Annotation of loncom/interface/lonnavmaps.pm, revision 1.118

1.72      bowersj2    1: 
1.2       www         2: # The LearningOnline Network with CAPA
                      3: # Navigate Maps Handler
1.1       www         4: #
1.118   ! bowersj2    5: # $Id: lonnavmaps.pm,v 1.117 2002/11/26 17:01:29 bowersj2 Exp $
1.20      albertel    6: #
                      7: # Copyright Michigan State University Board of Trustees
                      8: #
                      9: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
                     10: #
                     11: # LON-CAPA is free software; you can redistribute it and/or modify
                     12: # it under the terms of the GNU General Public License as published by
                     13: # the Free Software Foundation; either version 2 of the License, or
                     14: # (at your option) any later version.
                     15: #
                     16: # LON-CAPA is distributed in the hope that it will be useful,
                     17: # but WITHOUT ANY WARRANTY; without even the implied warranty of
                     18: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     19: # GNU General Public License for more details.
                     20: #
                     21: # You should have received a copy of the GNU General Public License
                     22: # along with LON-CAPA; if not, write to the Free Software
                     23: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
                     24: #
                     25: # /home/httpd/html/adm/gpl.txt
                     26: #
                     27: # http://www.lon-capa.org/
                     28: #
1.2       www        29: # (Page Handler
1.1       www        30: #
1.2       www        31: # (TeX Content Handler
1.1       www        32: #
1.2       www        33: # 05/29/00,05/30 Gerd Kortemeyer)
                     34: # 08/30,08/31,09/06,09/14,09/15,09/16,09/19,09/20,09/21,09/23,
                     35: # 10/02,10/10,10/14,10/16,10/18,10/19,10/31,11/6,11/14,11/16 Gerd Kortemeyer)
1.1       www        36: #
1.17      www        37: # 3/1/1,6/1,17/1,29/1,30/1,2/8,9/21,9/24,9/25 Gerd Kortemeyer
1.21      www        38: # YEAR=2002
                     39: # 1/1 Gerd Kortemeyer
1.105     bowersj2   40: # Oct-Nov Jeremy Bowers
1.2       www        41: 
1.1       www        42: package Apache::lonnavmaps;
                     43: 
                     44: use strict;
1.2       www        45: use Apache::Constants qw(:common :http);
1.18      albertel   46: use Apache::loncommon();
1.73      bowersj2   47: use POSIX qw (floor strftime);
1.2       www        48: 
1.1       www        49: sub handler {
1.99      bowersj2   50:     my $r = shift;
1.118   ! bowersj2   51:     real_handler($r);
        !            52: }
        !            53: 
        !            54: sub real_handler {
        !            55:     my $r = shift;
1.2       www        56: 
1.51      bowersj2   57:     &Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});
                     58: 
                     59:     # Handle header-only request
                     60:     if ($r->header_only) {
                     61:         if ($ENV{'browser.mathml'}) {
                     62:             $r->content_type('text/xml');
                     63:         } else {
                     64:             $r->content_type('text/html');
                     65:         }
                     66:         $r->send_http_header;
                     67:         return OK;
                     68:     }
                     69: 
                     70:     # Send header, don't cache this page
                     71:     if ($ENV{'browser.mathml'}) {
                     72:         $r->content_type('text/xml');
                     73:     } else {
                     74:         $r->content_type('text/html');
                     75:     }
                     76:     &Apache::loncommon::no_cache($r);
                     77:     $r->send_http_header;
                     78: 
1.106     bowersj2   79:     # Create the nav map
1.51      bowersj2   80:     my $navmap = Apache::lonnavmaps::navmap->new(
                     81:                         $ENV{"request.course.fn"}.".db",
1.80      bowersj2   82:                         $ENV{"request.course.fn"}."_parms.db", 1, 1);
1.51      bowersj2   83: 
1.55      bowersj2   84: 
                     85:     if (!defined($navmap)) {
                     86:         my $requrl = $r->uri;
                     87:         $ENV{'user.error.msg'} = "$requrl:bre:0:0:Course not initialized";
                     88:         return HTTP_NOT_ACCEPTABLE;
                     89:     }
1.64      bowersj2   90: 
1.111     bowersj2   91:     $r->print("<html><head>\n");
1.118   ! bowersj2   92:     $r->print("<title>Navigate Course Contents</title></head>");
1.111     bowersj2   93: 
1.64      bowersj2   94:     # Header
1.111     bowersj2   95:     $r->print(&Apache::loncommon::bodytag('Navigate Course Contents','',
1.64      bowersj2   96:                                           ''));
                     97:     $r->print('<script>window.focus();</script>');
1.101     bowersj2   98: 
1.95      bowersj2   99:     $r->print('<table border="0" cellpadding="2" cellspacing="0">');
1.64      bowersj2  100:     my $date=localtime;
1.95      bowersj2  101:     $r->print('<tr><td align="right" valign="bottom">Key:&nbsp;&nbsp;</td>');
1.101     bowersj2  102: 
                    103:     # Print discussions and feedback header
1.65      bowersj2  104:     if ($navmap->{LAST_CHECK}) {
1.95      bowersj2  105:         $r->print('<td align="center" valign="bottom">&nbsp;&nbsp;'.
                    106:                   '<img src="/adm/lonMisc/chat.gif"> New discussion since '.
1.73      bowersj2  107:                   strftime("%A, %b %e at %I:%M %P", localtime($navmap->{LAST_CHECK})).
1.95      bowersj2  108:                   '</td><td align="center" valign="bottom">&nbsp;&nbsp;'.
                    109:                   '<img src="/adm/lonMisc/feedback.gif"> New message (click to open)<p>'.
                    110:                   '</td>'); 
                    111:     } else {
                    112:         $r->print('<td align="center" valign="bottom">&nbsp;&nbsp;'.
                    113:                   '<img src="/adm/lonMisc/chat.gif"> Discussions</td><td align="center" valign="bottom">'.
                    114:                   '&nbsp;&nbsp;<img src="/adm/lonMisc/feedback.gif"> New message (click to open)'.
                    115:                   '</td>'); 
                    116:     }
                    117:     $r->print('</tr></table>');
1.101     bowersj2  118: 
1.95      bowersj2  119:     my $condition = 0;
                    120:     if ($ENV{'form.condition'}) {
                    121:         $condition = 1;
                    122:     }
                    123: 
1.118   ! bowersj2  124:     # Determine where the "here" marker is and where the screen jumps to.
        !           125:     my $SYMB = 1; my $URL = 2; my $NOTHING = 3; # symbolic constants
        !           126:     my $hereType; # the type of marker, $SYMB, $URL, or $NOTHING
        !           127:     my $here; # the actual URL or SYMB for the here marker
        !           128:     my $jumpType; # The type of the thing we have a jump for, $SYMB or $URL
        !           129:     my $jump; # the SYMB/URL of the resource we need to jump to
        !           130: 
        !           131:     if ( $ENV{'form.alreadyHere'} ) { # we came from a user's manipulation of the nav page
        !           132:         # If this is a click on a folder or something, we want to preserve the "here"
        !           133:         # from the querystring, and get the new "jump" marker
        !           134:         $hereType = $ENV{'form.hereType'};
        !           135:         $here = $ENV{'form.here'};
        !           136:         $jumpType = $ENV{'form.jumpType'} || $NOTHING;
        !           137:         $jump = $ENV{'form.jump'};
        !           138:     } else { # the user is visiting the nav map from the remote
        !           139:         # We're coming from the remote. We have either a url, a symb, or nothing,
        !           140:         # and we need to figure out what.
        !           141:         # Preference: Symb
        !           142:         
        !           143:         if ($ENV{'form.symb'}) {
        !           144:             $hereType = $jumpType = $SYMB;
        !           145:             $here = $jump = $ENV{'form.symb'};
        !           146:         } elsif ($ENV{'form.postdata'}) {
        !           147:             # couldn't find a symb, is there a URL?
        !           148:             my $currenturl = $ENV{'form.postdata'};
        !           149:             $currenturl=~s/^http\:\/\///;
        !           150:             $currenturl=~s/^[^\/]+//;
        !           151: 
        !           152:             $hereType = $jumpType = $URL;
        !           153:             $here = $jump = $currenturl;
        !           154:         } else {
        !           155:             # Nothing
        !           156:             $hereType = $jumpType = $NOTHING;
        !           157:         }
        !           158:     }
1.110     bowersj2  159: 
1.118   ! bowersj2  160:     
1.110     bowersj2  161:     # alreadyHere allows us to only open the maps necessary to view
                    162:     # the current location once, while at the same time remembering
                    163:     # the current location. Without that check, the user would never
                    164:     # be able to close those maps; the user would close it, and the
                    165:     # currenturl scan would re-open it.
1.118   ! bowersj2  166:     my $queryAdd = "&alreadyHere=1";
1.110     bowersj2  167: 
1.95      bowersj2  168:     if ($condition) {
1.118   ! bowersj2  169:         $r->print("<a href=\"navmaps?condition=0&filter=&$queryAdd" .
        !           170:                   "&hereType=$hereType&here=" . Apache::lonnet::escape($here) .
        !           171:                   "\">Close All Folders</a>");
1.65      bowersj2  172:     } else {
1.118   ! bowersj2  173:         $r->print("<a href=\"navmaps?condition=1&filter=&$queryAdd" .
        !           174:                   "&hereType=$hereType&here=" . Apache::lonnet::escape($here) . 
        !           175:                   "\">Open All Folders</a>");
1.65      bowersj2  176:     }
1.55      bowersj2  177: 
1.95      bowersj2  178:     $r->print('<br>&nbsp;');
                    179:     $r->rflush();
                    180: 
1.92      bowersj2  181:     # Now that we've displayed some stuff to the user, init the navmap
                    182:     $navmap->init();
                    183: 
1.55      bowersj2  184:     # Check that it's defined
                    185:     if (!($navmap->courseMapDefined())) {
                    186:         $r->print('<font size="+2" color="red">Coursemap undefined.</font>' .
                    187:                   '</body></html>');
                    188:         return OK;
                    189:     }
                    190: 
1.51      bowersj2  191:     # Grab a resource object so we have access to the constants; this
                    192:     # is technically not proper, but should be harmless
                    193:     my $res = $navmap->firstResource();
                    194: 
1.101     bowersj2  195:     # These are some data tables, which make it easy to change some of
                    196:     # of the specific visualization parameters if desired.
                    197: 
1.51      bowersj2  198:     # Defines a status->color mapping, null string means don't color
                    199:     my %colormap = 
1.54      bowersj2  200:     ( $res->NETWORK_FAILURE        => '',
1.59      bowersj2  201:       $res->CORRECT                => '',
1.112     bowersj2  202:       $res->EXCUSED                => '#3333FF',
1.59      bowersj2  203:       $res->PAST_DUE_ANSWER_LATER  => '',
                    204:       $res->PAST_DUE_NO_ANSWER     => '',
1.112     bowersj2  205:       $res->ANSWER_OPEN            => '#006600',
1.54      bowersj2  206:       $res->OPEN_LATER             => '',
1.59      bowersj2  207:       $res->TRIES_LEFT             => '',
                    208:       $res->INCORRECT              => '',
                    209:       $res->OPEN                   => '',
1.54      bowersj2  210:       $res->NOTHING_SET            => ''        );
1.59      bowersj2  211:     # And a special case in the nav map; what to do when the assignment
                    212:     # is not yet done and due in less then 24 hours
1.86      bowersj2  213:     my $hurryUpColor = "#FF0000";
1.59      bowersj2  214: 
1.115     bowersj2  215:     # Keep these mappings in sync with lonquickgrades, which uses the colors
                    216:     # instead of the icons.
1.59      bowersj2  217:     my %statusIconMap = 
1.66      bowersj2  218:         ( $res->NETWORK_FAILURE    => '',
                    219:           $res->NOTHING_SET        => '',
                    220:           $res->CORRECT            => 'navmap.correct.gif',
                    221:           $res->EXCUSED            => 'navmap.correct.gif',
                    222:           $res->PAST_DUE_NO_ANSWER => 'navmap.wrong.gif',
                    223:           $res->PAST_DUE_ANSWER_LATER => 'navmap.wrong.gif',
                    224:           $res->ANSWER_OPEN        => 'navmap.wrong.gif',
                    225:           $res->OPEN_LATER         => '',
                    226:           $res->TRIES_LEFT         => 'navmap.open.gif',
                    227:           $res->INCORRECT          => 'navmap.wrong.gif',
1.69      bowersj2  228:           $res->OPEN               => 'navmap.open.gif',
1.85      bowersj2  229:           $res->ATTEMPTED          => 'navmap.open.gif' );
1.69      bowersj2  230: 
                    231:     my %iconAltTags = 
                    232:         ( 'navmap.correct.gif' => 'Correct',
                    233:           'navmap.wrong.gif'   => 'Incorrect',
                    234:           'navmap.open.gif'    => 'Open' );
1.59      bowersj2  235: 
                    236:     my %condenseStatuses =
1.66      bowersj2  237:         ( $res->NETWORK_FAILURE    => 1,
                    238:           $res->NOTHING_SET        => 1,
                    239:           $res->CORRECT            => 1 );
1.51      bowersj2  240: 
                    241:     my %filterHash;
                    242:     # Figure out what we're not displaying
                    243:     foreach (split(/\,/, $ENV{"form.filter"})) {
                    244:         if ($_) {
                    245:             $filterHash{$_} = "1";
                    246:         }
                    247:     }
                    248: 
1.88      bowersj2  249:     # Is this a new-style course? If so, we want to suppress showing the top-level
                    250:     # maps in their own folders, in favor of "inlining" them.
                    251:     my $topResource = $navmap->getById("0.0");
1.63      bowersj2  252: 
1.51      bowersj2  253:     # Begin the HTML table
1.59      bowersj2  254:     # four cols: resource + indent, chat+feedback, icon, text string
1.85      bowersj2  255:     $r->print('<table cellspacing="0" cellpadding="3" border="0" bgcolor="#FFFFFF">' ."\n");
1.51      bowersj2  256: 
1.74      bowersj2  257:     # This needs to be updated to use symbs from the remote, 
                    258:     # instead of uris. The changes to this and the main rendering
                    259:     # loop should be obvious.
                    260:     # Here's a simple example of the iterator.
1.88      bowersj2  261:     # Preprocess the map: Look for current URL, force inlined maps to display
                    262: 
1.118   ! bowersj2  263:     my $mapIterator = $navmap->getIterator(undef, undef, undef, 1);
1.88      bowersj2  264:     my $found = 0;
                    265:     my $depth = 1;
1.118   ! bowersj2  266:     my $currentJumpIndex = 0; # keeps track of when the current resource is found,
1.91      bowersj2  267:                              # so we can back up a few and put the anchor above the
                    268:                              # current resource
1.118   ! bowersj2  269:     my $currentJumpDelta = 2; # change this to change how many resources are displayed
1.101     bowersj2  270:                              # before the current resource when using #current
1.88      bowersj2  271:     $mapIterator->next(); # discard the first BEGIN_MAP
                    272:     my $curRes = $mapIterator->next();
1.91      bowersj2  273:     my $counter = 0;
1.118   ! bowersj2  274:     my $foundJump = ($jumpType == $NOTHING); # look for jump point if we have one
        !           275:     my $looped = 0; 
1.116     bowersj2  276: 
                    277:     # We only need to do this if we need to open the maps to show the
1.118   ! bowersj2  278:     # current position. This will change the counter so we can't count
        !           279:     # for the jump marker with this loop.
1.116     bowersj2  280:     while ($depth > 0 && !$ENV{'form.alreadyHere'}) {
1.96      bowersj2  281:         if ($curRes == $mapIterator->BEGIN_MAP()) { $depth++; }
                    282:         if ($curRes == $mapIterator->END_MAP()) { $depth--; }
1.118   ! bowersj2  283:         if (ref($curRes) && !$ENV{'form.alreadyHere'} && 
        !           284:             ($hereType == $SYMB && $curRes->symb() eq $here) ||
        !           285:             ($hereType == $URL && $curRes->src() eq $here)) {
        !           286:             my $mapStack = $mapIterator->getStack();
        !           287:             
        !           288:             # Ensure the parent maps are open
        !           289:             for my $map (@{$mapStack}) {
        !           290:                 if ($condition) {
        !           291:                     undef $filterHash{$map->map_pc()};
        !           292:                 } else {
        !           293:                     $filterHash{$map->map_pc()} = 1;
        !           294:                 }
        !           295:             }
        !           296:             $ENV{'form.alreadyHere'} = 1;
        !           297:         }
        !           298:         $looped = 1;
        !           299: 
        !           300:         $curRes = $mapIterator->next();
        !           301:     }            
        !           302:     
        !           303:     $mapIterator = $navmap->getIterator(undef, undef, \%filterHash, 0);
        !           304:     $depth = 1;
        !           305:     $mapIterator->next();
        !           306:     $curRes = $mapIterator->next();
1.88      bowersj2  307: 
1.118   ! bowersj2  308:     while ($depth > 0 && !$foundJump) {
        !           309:         if ($curRes == $mapIterator->BEGIN_MAP()) { $depth++; }
        !           310:         if ($curRes == $mapIterator->END_MAP()) { $depth--; }
1.91      bowersj2  311:         if (ref($curRes)) { $counter++; }
                    312: 
1.118   ! bowersj2  313:         if (ref($curRes) && 
        !           314:             (($jumpType == $SYMB && $curRes->symb() eq $jump) ||
        !           315:             ($jumpType == $URL && $curRes->src() eq $jump))) {
1.88      bowersj2  316:             # If this is the correct resource, be sure to 
                    317:             # show it by making sure the containing maps
                    318:             # are open.
1.91      bowersj2  319: 
1.101     bowersj2  320:             # This is why we have to use the main iterator instead of the
                    321:             # potentially faster DFS: The count has to be the same, so
                    322:             # the order has to be the same, which DFS won't give us.
1.118   ! bowersj2  323:             $currentJumpIndex = $counter;
        !           324:             $foundJump = 1;
1.88      bowersj2  325:         }
1.118   ! bowersj2  326: 
1.88      bowersj2  327:         $curRes = $mapIterator->next();
1.74      bowersj2  328:     }
1.88      bowersj2  329:     
1.53      bowersj2  330:     undef $res; # so we don't accidentally use it later
1.72      bowersj2  331:     my $indentLevel = 0;
1.61      bowersj2  332:     my $indentString = "<img src=\"/adm/lonIcons/whitespace1.gif\" width=\"25\" height=\"1\" alt=\"\" border=\"0\" />";
1.51      bowersj2  333: 
                    334:     my $isNewBranch = 0;
1.59      bowersj2  335:     my $now = time();
                    336:     my $in24Hours = $now + 24 * 60 * 60;
1.78      bowersj2  337:     my $displayedHereMarker = 0;
1.118   ! bowersj2  338:     my $displayedJumpMarker = 0;
1.88      bowersj2  339:     
1.72      bowersj2  340:     # We know the first thing is a BEGIN_MAP (see "$self->{STARTED}"
                    341:     # code in iterator->next), so ignore the first one
1.89      bowersj2  342:     $mapIterator = $navmap->getIterator(undef, undef, \%filterHash,
1.74      bowersj2  343:                                            $condition);
1.72      bowersj2  344:     $mapIterator->next();
1.89      bowersj2  345:     $curRes = $mapIterator->next();
1.90      bowersj2  346:     $depth = 1;
1.88      bowersj2  347: 
                    348:     my @backgroundColors = ("#FFFFFF", "#F6F6F6");
                    349:     my $rowNum = 0;
1.51      bowersj2  350: 
1.91      bowersj2  351:     $counter = 0;
                    352: 
1.72      bowersj2  353:     while ($depth > 0) {
1.51      bowersj2  354:         if ($curRes == $mapIterator->BEGIN_MAP() ||
1.52      bowersj2  355:             $curRes == $mapIterator->BEGIN_BRANCH()) {
1.51      bowersj2  356:             $indentLevel++;
                    357:         }
                    358:         if ($curRes == $mapIterator->END_MAP() ||
1.52      bowersj2  359:             $curRes == $mapIterator->END_BRANCH()) {
1.51      bowersj2  360:             $indentLevel--;
                    361:         }
1.52      bowersj2  362:         if ($curRes == $mapIterator->BEGIN_BRANCH()) {
                    363:             $isNewBranch = 1;
1.72      bowersj2  364:         }
1.96      bowersj2  365:         if ($curRes == $mapIterator->BEGIN_MAP()) { $depth++; }
                    366:         if ($curRes == $mapIterator->END_MAP()) { $depth--; }
1.51      bowersj2  367: 
1.91      bowersj2  368:         if (ref($curRes)) { $counter++; }
                    369: 
1.101     bowersj2  370:         # Is this resource being ignored because it is in a random-out
                    371:         # map and it was not selected?
1.68      bowersj2  372:         if (ref($curRes) && !advancedUser() && $curRes->randomout()) {
                    373:             $curRes = $mapIterator->next();
1.101     bowersj2  374:             next; # if yes, then just ignore this resource
1.68      bowersj2  375:         }
                    376: 
1.116     bowersj2  377:         if (ref($curRes)) {
1.51      bowersj2  378: 
1.113     bowersj2  379:             my $deltalevel = $isNewBranch? 1 : 0; # reserves space for branch icon
                    380: 
1.116     bowersj2  381:             if ($indentLevel - $deltalevel < 0) {
1.113     bowersj2  382:                 # If this would be at a negative depth (top-level maps in
                    383:                 # new-style courses, we want to suppress their title display)
                    384:                 # then ignore it.
                    385:                 $curRes = $mapIterator->next();
                    386:                 next;
                    387:             }
                    388: 
1.66      bowersj2  389:             # Step one: Decide which parts to show
                    390:             my @parts = @{$curRes->parts()};
                    391:             my $multipart = scalar(@parts) > 1;
                    392:             my $condensed = 0;
                    393:                 
1.51      bowersj2  394:             if ($curRes->is_problem()) {
1.101     bowersj2  395: 
1.66      bowersj2  396:                 # Is it multipart?
                    397:                 if ($multipart) {
                    398:                     # If it's multipart, see if part 0 is "open"
                    399:                     # if it is, display all parts, if it isn't,
                    400:                     # just display first
                    401:                     if (!$curRes->opendate("0")) {
1.101     bowersj2  402:                         # no parts are open, display as one part
                    403:                         @parts = ("0");
1.68      bowersj2  404:                         $condensed = 1;
1.66      bowersj2  405:                     } else {
                    406:                         # Otherwise, only display part 0 if we want to 
                    407:                         # attach feedback or email information to it
                    408:                         if ($curRes->hasDiscussion() || $curRes->getFeedback()) {
                    409:                             shift @parts;
                    410:                         } else {
                    411:                             # Now, we decide whether to condense the
                    412:                             # parts due to similarity
                    413:                             my $status = $curRes->status($parts[1]);
                    414:                             my $due = $curRes->duedate($parts[1]);
                    415:                             my $open = $curRes->opendate($parts[1]);
                    416:                             my $statusAllSame = 1;
                    417:                             my $dueAllSame = 1;
                    418:                             my $openAllSame = 1;
                    419:                             for (my $i = 2; $i < scalar(@parts); $i++) {
                    420:                                 if ($curRes->status($parts[$i]) != $status){
                    421:                                     $statusAllSame = 0;
                    422:                                 }
                    423:                                 if ($curRes->duedate($parts[$i]) != $due ) {
                    424:                                     $dueAllSame = 0;
                    425:                                 }
                    426:                                 if ($curRes->opendate($parts[$i]) != $open) {
                    427:                                     $openAllSame = 0;
                    428:                                 }
                    429:                             }
                    430:                             
                    431:                             # $allSame is true if all the statuses were
                    432:                             # the same. Now, if they are all the same and
                    433:                             # match one of the statuses to condense, or they
                    434:                             # are all open with the same due date, or they are
                    435:                             # all OPEN_LATER with the same open date, display the
                    436:                             # status of the first non-zero part (to get the 'correct'
                    437:                             # status right, since 0 is never 'correct' or 'open').
                    438:                             if (($statusAllSame && defined($condenseStatuses{$status})) ||
                    439:                                 ($dueAllSame && $status == $curRes->OPEN && $statusAllSame)||
                    440:                                 ($openAllSame && $status == $curRes->OPEN_LATER && $statusAllSame) ){
                    441:                                 @parts = ($parts[1]);
                    442:                                 $condensed = 1;
                    443:                             }
                    444:                         }
                    445:                     }
                    446:                 }
1.59      bowersj2  447: 
1.51      bowersj2  448:             } else {
1.84      bowersj2  449:                 $parts[0] = "0"; # this is to get past foreach loop below
1.51      bowersj2  450:                  # you can consider a non-problem resource as a resource
1.101     bowersj2  451:                   # with only one part without loss, and it simplifies the looping
1.51      bowersj2  452:             }
                    453: 
1.83      bowersj2  454:             # Is it a multipart problem with a single part, now in 
1.101     bowersj2  455:             # @parts with "0" filtered out? If so, 'forget' it's a multi-part
1.83      bowersj2  456:             # problem and treat it like a single-part problem.
                    457:             if ( scalar(@parts) == 1 ) {
                    458:                 $multipart = 0;
                    459:             }
                    460: 
1.66      bowersj2  461:             # Display one part, in event of network error.
                    462:             # If this is a single part, we can at least show the correct
1.101     bowersj2  463:             # status, but if it's multipart, we're lost, since we can't
                    464:             # retreive the metadata to count the parts
1.66      bowersj2  465:             if ($curRes->{RESOURCE_ERROR}) {
                    466:                 @parts = ("0");
                    467:             }
                    468: 
1.101     bowersj2  469:             # Step Two: Print the actual data.
                    470: 
                    471:             # For each part we intend to display...
1.51      bowersj2  472:             foreach my $part (@parts) {
1.59      bowersj2  473: 
1.68      bowersj2  474:                 my $nonLinkedText = ""; # unlinked stuff after title
1.51      bowersj2  475:                 
                    476:                 my $stack = $mapIterator->getStack();
                    477:                 my $src = getLinkForResource($stack);
                    478: 
1.101     bowersj2  479:                 # Pass the correct symb on the querystring, so the
                    480:                 # remote will figure out where we are if we click a link
1.51      bowersj2  481:                 my $srcHasQuestion = $src =~ /\?/;
                    482:                 my $link = $src.
                    483:                     ($srcHasQuestion?'&':'?') .
                    484:                     'symb='.&Apache::lonnet::escape($curRes->symb()).
                    485:                     '"';
1.101     bowersj2  486: 
1.106     bowersj2  487:                 my $title = $curRes->compTitle();
1.51      bowersj2  488:                 my $partLabel = "";
1.52      bowersj2  489:                 my $newBranchText = "";
                    490: 
                    491:                 # If this is a new branch, label it so
                    492:                 if ($isNewBranch) {
1.59      bowersj2  493:                     $newBranchText = "<img src=\"/adm/lonIcons/branch.gif\" border=\"0\">";
1.52      bowersj2  494:                     $isNewBranch = 0;
                    495:                 }
1.51      bowersj2  496: 
                    497:                 # links to open and close the folders
                    498:                 my $linkopen = "<a href=\"$link\">";
                    499:                 my $linkclose = "</a>";
                    500: 
1.61      bowersj2  501:                 my $icon = "<img src=\"/adm/lonIcons/html.gif\" alt=\"\" border=\"0\" />";
1.51      bowersj2  502:                 if ($curRes->is_problem()) { 
1.66      bowersj2  503:                     if ($part eq "0" || $condensed) {
                    504:                         $icon = '<img src="/adm/lonIcons/problem.gif" alt="" border=\"0\" />'; 
                    505:                     } else {
                    506:                         $icon = $indentString;
                    507:                     }
1.51      bowersj2  508:                 }
                    509: 
                    510:                 # Display the correct icon, link to open or shut map
                    511:                 if ($curRes->is_map()) { 
                    512:                     my $mapId = $curRes->map_pc();
1.82      bowersj2  513:                     my $nowOpen = (!defined($filterHash{$mapId}));
                    514:                     if ($condition) {$nowOpen = !$nowOpen;}
1.51      bowersj2  515:                     $icon = $nowOpen ?
1.77      bowersj2  516:                         "navmap.folder.closed.gif" : "navmap.folder.open.gif";
1.66      bowersj2  517:                     $icon = "<img src=\"/adm/lonIcons/$icon\" alt=\"\" border=\"0\" />";
1.52      bowersj2  518:                     $linkopen = "<a href=\"/adm/navmaps?filter=";
1.66      bowersj2  519:                     $linkopen .= ($nowOpen xor $condition) ? 
1.51      bowersj2  520:                         addToFilter(\%filterHash, $mapId) :
                    521:                         removeFromFilter(\%filterHash, $mapId);
1.118   ! bowersj2  522:                     $linkopen .= "&condition=$condition&$queryAdd" . 
        !           523:                         "&hereType=$hereType&here=" . 
        !           524:                         Apache::lonnet::escape($here) . "&jumpType=$SYMB&" .
        !           525:                         "jump=" . Apache::lonnet::escape($curRes->symb()) ."\">";
1.51      bowersj2  526:                     $linkclose = "</a>";
1.68      bowersj2  527: 
1.51      bowersj2  528:                 }
                    529:                 
                    530:                 my $colorizer = "";
1.86      bowersj2  531:                 my $color;
1.51      bowersj2  532:                 if ($curRes->is_problem()) {
1.115     bowersj2  533:                     $color = $colormap{$curRes->status};
1.74      bowersj2  534: 
1.115     bowersj2  535:                     if (dueInLessThen24Hours($curRes, $part) ||
                    536:                         lastTry($curRes, $part)) {
1.79      bowersj2  537:                         $color = $hurryUpColor;
                    538:                     }
1.115     bowersj2  539: 
1.51      bowersj2  540:                     if ($color ne "") {
                    541:                         $colorizer = "bgcolor=\"$color\"";
                    542:                     }
                    543:                 }
                    544: 
1.68      bowersj2  545:                 if ($curRes->randomout()) {
                    546:                     $nonLinkedText .= ' <i>(hidden)</i> ';
                    547:                 }
                    548: 
1.88      bowersj2  549:                 $rowNum++;
                    550:                 my $backgroundColor = $backgroundColors[$rowNum % scalar(@backgroundColors)];
                    551: 
1.91      bowersj2  552:                 # FIRST COL: The resource indentation, branch icon, name, and anchor
1.116     bowersj2  553:                 $r->print("  <tr bgcolor=\"$backgroundColor\"><td align=\"left\" valign=\"center\">\n");
1.51      bowersj2  554: 
1.101     bowersj2  555:                 # Print the anchor if necessary
1.118   ! bowersj2  556:                 if ($counter == $currentJumpIndex - $currentJumpDelta ) {
        !           557:                     $r->print('<a name="curloc" />');
        !           558:                     $displayedJumpMarker = 1;
1.91      bowersj2  559:                 }
                    560: 
1.51      bowersj2  561:                 # print indentation
1.116     bowersj2  562:                 for (my $i = 0; $i < $indentLevel - $deltalevel; $i++) {
1.51      bowersj2  563:                     $r->print($indentString);
                    564:                 }
                    565: 
1.61      bowersj2  566:                 $r->print("  ${newBranchText}${linkopen}$icon${linkclose}\n");
1.51      bowersj2  567: 
1.74      bowersj2  568:                 my $curMarkerBegin = "";
                    569:                 my $curMarkerEnd = "";
                    570: 
                    571:                 # Is this the current resource?
1.118   ! bowersj2  572:                 if (!$displayedHereMarker && 
        !           573:                     (($hereType == $SYMB && $curRes->symb eq $here) ||
        !           574:                     ($hereType == $URL && $curRes->src eq $here))) {
        !           575:                     $curMarkerBegin = '<font color="red" size="+2">&gt; </font>';
1.74      bowersj2  576:                     $curMarkerEnd = '<font color="red" size="+2"> &lt;</font>';
1.78      bowersj2  577:                     $displayedHereMarker = 1;
1.74      bowersj2  578:                 }
                    579: 
1.69      bowersj2  580:                 if ($curRes->is_problem() && $part ne "0" && !$condensed) { 
1.66      bowersj2  581:                     $partLabel = " (Part $part)"; 
                    582:                     $title = "";
                    583:                 }
1.83      bowersj2  584:                 if ($multipart && $condensed) {
1.68      bowersj2  585:                     $nonLinkedText .= ' (' . $curRes->countParts() . ' parts)';
1.66      bowersj2  586:                 }
1.59      bowersj2  587: 
1.74      bowersj2  588:                 $r->print("  $curMarkerBegin<a href=\"$link\">$title$partLabel</a> $curMarkerEnd $nonLinkedText");
1.66      bowersj2  589: 
1.118   ! bowersj2  590:                 #if ($curRes->{RESOURCE_ERROR}) {
        !           591:                 #    $r->print(&Apache::loncommon::help_open_topic ("Navmap_Host_Down",
        !           592:                 #                              '<font size="-1">Host down</font>'));
        !           593:                 #    }
1.66      bowersj2  594: 
1.113     bowersj2  595:                 $r->print("</td>\n");
                    596: 
1.101     bowersj2  597:                 # SECOND COL: Is there text, feedback, errors??
1.66      bowersj2  598:                 my $discussionHTML = ""; my $feedbackHTML = "";
                    599: 
                    600:                 if ($curRes->hasDiscussion()) {
                    601:                     $discussionHTML = $linkopen .
                    602:                         '<img border="0" src="/adm/lonMisc/chat.gif" />' .
                    603:                         $linkclose;
                    604:                 }
                    605: 
                    606:                 if ($curRes->getFeedback()) {
                    607:                     my $feedback = $curRes->getFeedback();
                    608:                     foreach (split(/\,/, $feedback)) {
                    609:                         if ($_) {
                    610:                             $feedbackHTML .= '&nbsp;<a href="/adm/email?display='
                    611:                                 . &Apache::lonnet::escape($_) . '">'
                    612:                                 . '<img src="/adm/lonMisc/feedback.gif" '
                    613:                                 . 'border="0" /></a>';
                    614:                         }
                    615:                     }
                    616:                 }
                    617: 
1.84      bowersj2  618:                 $r->print("<td width=\"75\" align=\"left\" valign=\"center\">$discussionHTML$feedbackHTML&nbsp;</td>");
1.66      bowersj2  619: 
                    620:                 # Is this the first displayed part of a multi-part problem
                    621:                 # that has not been condensed, so we should suppress these two
1.101     bowersj2  622:                 # columns so we don't display useless status info about part
                    623:                 # "0"?
1.66      bowersj2  624:                 my $firstDisplayed = !$condensed && $multipart && $part eq "0";
                    625: 
1.69      bowersj2  626:                 # THIRD COL: Problem status icon
1.66      bowersj2  627:                 if ($curRes->is_problem() &&
                    628:                     !$firstDisplayed) {
                    629:                     my $icon = $statusIconMap{$curRes->status($part)};
1.69      bowersj2  630:                     my $alt = $iconAltTags{$icon};
1.66      bowersj2  631:                     if ($icon) {
1.84      bowersj2  632:                         $r->print("<td width=\"30\" valign=\"center\" width=\"50\" align=\"right\">$linkopen<img width=\"25\" height=\"25\" src=\"/adm/lonIcons/$icon\" border=\"0\" alt=\"$alt\" />$linkclose</td>\n");
1.66      bowersj2  633:                     } else {
1.84      bowersj2  634:                         $r->print("<td width=\"30\">&nbsp;</td>\n");
1.66      bowersj2  635:                     }
                    636:                 } else { # not problem, no icon
1.84      bowersj2  637:                     $r->print("<td width=\"30\">&nbsp;</td>\n");
1.66      bowersj2  638:                 }
                    639: 
1.69      bowersj2  640:                 # FOURTH COL: Text description
1.86      bowersj2  641:                 $r->print("<td align=\"right\" valign=\"center\">\n");
1.51      bowersj2  642:                 
1.61      bowersj2  643:                 if ($curRes->kind() eq "res" &&
                    644:                     $curRes->is_problem() &&
1.66      bowersj2  645:                     !$firstDisplayed) {
1.86      bowersj2  646:                     $r->print ("<font color=\"$color\"><b>") if ($color);
1.53      bowersj2  647:                     $r->print (getDescription($curRes, $part));
1.86      bowersj2  648:                     $r->print ("</b></font>") if ($color);
1.51      bowersj2  649:                 }
1.68      bowersj2  650:                 if ($curRes->is_map() && advancedUser() && $curRes->randompick()) {
                    651:                     $r->print('(randomly select ' . $curRes->randompick() .')');
                    652:                 }
1.59      bowersj2  653: 
1.84      bowersj2  654:                 $r->print("&nbsp;</td></tr>\n");
1.113     bowersj2  655: 
                    656:                 if (!($counter % 20)) { $r->rflush(); }
                    657:                 if ($counter == 2) { $r->rflush(); }
1.51      bowersj2  658:             }
                    659:         }
                    660:         $curRes = $mapIterator->next();
                    661:     }
                    662: 
1.118   ! bowersj2  663:     $r->print("</table>");
        !           664: 
        !           665:     # Print out the part that jumps to #curloc if it exists
        !           666:     if ($displayedJumpMarker) {
        !           667:         $r->print('<script>location += "#curloc";</script>');
        !           668:     }
        !           669: 
        !           670:     $r->print("</body></html>");
1.51      bowersj2  671: 
1.59      bowersj2  672:     $navmap->untieHashes();
                    673: 
1.51      bowersj2  674:     return OK;
                    675: }
                    676: 
                    677: # Convenience functions: Returns a string that adds or subtracts
                    678: # the second argument from the first hash, appropriate for the 
                    679: # query string that determines which folders to recurse on
                    680: sub addToFilter {
                    681:     my $hashIn = shift;
                    682:     my $addition = shift;
                    683:     my %hash = %$hashIn;
                    684:     $hash{$addition} = 1;
                    685: 
                    686:     return join (",", keys(%hash));
                    687: }
                    688: 
                    689: sub removeFromFilter {
                    690:     my $hashIn = shift;
                    691:     my $subtraction = shift;
                    692:     my %hash = %$hashIn;
                    693: 
                    694:     delete $hash{$subtraction};
                    695:     return join(",", keys(%hash));
                    696: }
                    697: 
                    698: # Convenience function: Given a stack returned from getStack on the iterator,
                    699: # return the correct src() value.
                    700: # Later, this should add an anchor when we start putting anchors in pages.
                    701: sub getLinkForResource {
                    702:     my $stack = shift;
                    703:     my $res;
                    704: 
                    705:     # Check to see if there are any pages in the stack
                    706:     foreach $res (@$stack) {
                    707:         if (defined($res) && $res->is_page()) {
                    708:             return $res->src();
                    709:         }
                    710:     }
                    711: 
                    712:     # Failing that, return the src of the last resource that is defined
                    713:     # (when we first recurse on a map, it puts an undefined resource
                    714:     # on the bottom because $self->{HERE} isn't defined yet, and we
                    715:     # want the src for the map anyhow)
                    716:     foreach (@$stack) {
                    717:         if (defined($_)) { $res = $_; }
                    718:     }
                    719: 
                    720:     return $res->src();
                    721: }
                    722: 
1.53      bowersj2  723: # Convenience function: This seperates the logic of how to create
                    724: # the problem text strings ("Due: DATE", "Open: DATE", "Not yet assigned",
                    725: # etc.) into a seperate function. It takes a resource object as the
                    726: # first parameter, and the part number of the resource as the second.
                    727: # It's basically a big switch statement on the status of the resource.
                    728: 
                    729: sub getDescription {
                    730:     my $res = shift;
                    731:     my $part = shift;
1.69      bowersj2  732:     my $status = $res->status($part);
1.53      bowersj2  733: 
                    734:     if ($status == $res->NETWORK_FAILURE) { return ""; }
                    735:     if ($status == $res->NOTHING_SET) {
                    736:         return "Not currently assigned.";
                    737:     }
                    738:     if ($status == $res->OPEN_LATER) {
1.73      bowersj2  739:         return "Open " . timeToHumanString($res->opendate($part));
1.53      bowersj2  740:     }
                    741:     if ($status == $res->OPEN) {
1.79      bowersj2  742:         if ($res->duedate($part)) {
1.73      bowersj2  743:             return "Due " . timeToHumanString($res->duedate($part));
1.66      bowersj2  744:         } else {
                    745:             return "Open, no due date";
                    746:         }
1.53      bowersj2  747:     }
1.54      bowersj2  748:     if ($status == $res->PAST_DUE_ANSWER_LATER) {
1.73      bowersj2  749:         return "Answer open " . timeToHumanString($res->answerdate($part));
1.54      bowersj2  750:     }
                    751:     if ($status == $res->PAST_DUE_NO_ANSWER) {
1.73      bowersj2  752:         return "Was due " . timeToHumanString($res->duedate($part));
1.53      bowersj2  753:     }
                    754:     if ($status == $res->ANSWER_OPEN) {
                    755:         return "Answer available";
                    756:     }
1.59      bowersj2  757:     if ($status == $res->EXCUSED) {
1.66      bowersj2  758:         return "Excused by instructor";
1.59      bowersj2  759:     }
1.69      bowersj2  760:     if ($status == $res->ATTEMPTED) {
                    761:         return "Not yet graded.";
                    762:     }
1.59      bowersj2  763:     if ($status == $res->TRIES_LEFT) {
1.79      bowersj2  764:         my $tries = $res->tries($part);
                    765:         my $maxtries = $res->maxtries($part);
                    766:         my $triesString = "";
                    767:         if ($tries && $maxtries) {
                    768:             $triesString = "<font size=\"-1\"><i>($tries of $maxtries tries used)</i></font>";
                    769:             if ($maxtries > 1 && $maxtries - $tries == 1) {
                    770:                 $triesString = "<b>$triesString</b>";
                    771:             }
                    772:         }
1.66      bowersj2  773:         if ($res->duedate()) {
1.73      bowersj2  774:             return "Due " . timeToHumanString($res->duedate($part)) .
1.66      bowersj2  775:                 " $triesString";
                    776:         } else {
                    777:             return "No due date $triesString";
                    778:         }
1.59      bowersj2  779:     }
1.53      bowersj2  780: }
                    781: 
1.115     bowersj2  782: # Convenience function, so others can use it: Is the problem due in less then
                    783: # 24 hours, and still can be done?
                    784: 
                    785: sub dueInLessThen24Hours {
                    786:     my $res = shift;
                    787:     my $part = shift;
                    788:     my $status = $res->status($part);
                    789: 
                    790:     return ($status == $res->OPEN() || $status == $res->ATTEMPTED() ||
                    791:             $status == $res->TRIES_LEFT()) &&
                    792:            $res->duedate() && $res->duedate() < time()+(24*60*60) &&
                    793:            $res->duedate() > time();
                    794: }
                    795: 
                    796: # Convenience function, so others can use it: Is there only one try remaining for the
                    797: # part, with more then one try to begin with, not due yet and still can be done?
                    798: sub lastTry {
                    799:     my $res = shift;
                    800:     my $part = shift;
                    801: 
                    802:     my $tries = $res->tries($part);
                    803:     my $maxtries = $res->maxtries($part);
                    804:     return $tries && $maxtries && $maxtries > 1 &&
                    805:         $maxtries - $tries == 1 && $res->duedate() &&
                    806:         $res->duedate() > time();
                    807: }
                    808: 
1.101     bowersj2  809: # This puts a human-readable name on the ENV variable.
1.68      bowersj2  810: sub advancedUser {
                    811:     return $ENV{'user.adv'};
                    812: }
                    813: 
1.73      bowersj2  814: 
                    815: # timeToHumanString takes a time number and converts it to a
                    816: # human-readable representation, meant to be used in the following
                    817: # manner:
                    818: # print "Due $timestring"
                    819: # print "Open $timestring"
                    820: # print "Answer available $timestring"
                    821: # Very, very, very, VERY English-only... goodness help a localizer on
                    822: # this func...
1.53      bowersj2  823: sub timeToHumanString {
1.58      albertel  824:     my ($time) = @_;
                    825:     # zero, '0' and blank are bad times
1.73      bowersj2  826:     if (!$time) {
                    827:         return 'never';
                    828:     }
                    829: 
                    830:     my $now = time();
                    831: 
                    832:     my @time = localtime($time);
                    833:     my @now = localtime($now);
                    834: 
                    835:     # Positive = future
                    836:     my $delta = $time - $now;
                    837: 
                    838:     my $minute = 60;
                    839:     my $hour = 60 * $minute;
                    840:     my $day = 24 * $hour;
                    841:     my $week = 7 * $day;
                    842:     my $inPast = 0;
                    843: 
                    844:     # Logic in comments:
                    845:     # Is it now? (extremely unlikely)
                    846:     if ( $delta == 0 ) {
                    847:         return "this instant";
                    848:     }
                    849: 
                    850:     if ($delta < 0) {
                    851:         $inPast = 1;
                    852:         $delta = -$delta;
                    853:     }
                    854: 
                    855:     if ( $delta > 0 ) {
1.101     bowersj2  856: 
1.73      bowersj2  857:         my $tense = $inPast ? " ago" : "";
                    858:         my $prefix = $inPast ? "" : "in ";
1.101     bowersj2  859:         
                    860:         # Less then a minute
1.73      bowersj2  861:         if ( $delta < $minute ) {
                    862:             if ($delta == 1) { return "${prefix}1 second$tense"; }
                    863:             return "$prefix$delta seconds$tense";
                    864:         }
                    865: 
1.101     bowersj2  866:         # Less then an hour
1.73      bowersj2  867:         if ( $delta < $hour ) {
                    868:             # If so, use minutes
                    869:             my $minutes = floor($delta / 60);
                    870:             if ($minutes == 1) { return "${prefix}1 minute$tense"; }
                    871:             return "$prefix$minutes minutes$tense";
                    872:         }
                    873:         
                    874:         # Is it less then 24 hours away? If so,
                    875:         # display hours + minutes
                    876:         if ( $delta < $hour * 24) {
                    877:             my $hours = floor($delta / $hour);
                    878:             my $minutes = floor(($delta % $hour) / $minute);
                    879:             my $hourString = "$hours hours";
                    880:             my $minuteString = ", $minutes minutes";
                    881:             if ($hours == 1) {
                    882:                 $hourString = "1 hour";
                    883:             }
                    884:             if ($minutes == 1) {
                    885:                 $minuteString = ", 1 minute";
                    886:             }
                    887:             if ($minutes == 0) {
                    888:                 $minuteString = "";
                    889:             }
                    890:             return "$prefix$hourString$minuteString$tense";
                    891:         }
                    892: 
                    893:         # Less then 5 days away, display day of the week and
                    894:         # HH:MM
                    895:         if ( $delta < $day * 5 ) {
1.85      bowersj2  896:             my $timeStr = strftime("%A, %b %e at %I:%M %P", localtime($time));
1.73      bowersj2  897:             $timeStr =~ s/12:00 am/midnight/;
                    898:             $timeStr =~ s/12:00 pm/noon/;
                    899:             return ($inPast ? "last " : "next ") .
                    900:                 $timeStr;
                    901:         }
                    902:         
                    903:         # Is it this year?
                    904:         if ( $time[5] == $now[5]) {
                    905:             # Return on Month Day, HH:MM meridian
                    906:             my $timeStr = strftime("on %A, %b %e at %I:%M %P", localtime($time));
                    907:             $timeStr =~ s/12:00 am/midnight/;
                    908:             $timeStr =~ s/12:00 pm/noon/;
                    909:             return $timeStr;
                    910:         }
                    911: 
                    912:         # Not this year, so show the year
                    913:         my $timeStr = strftime("on %A, %b %e %G at %I:%M %P", localtime($time));
                    914:         $timeStr =~ s/12:00 am/midnight/;
                    915:         $timeStr =~ s/12:00 pm/noon/;
                    916:         return $timeStr;
1.58      albertel  917:     }
1.53      bowersj2  918: }
                    919: 
1.51      bowersj2  920: 1;
                    921: 
                    922: package Apache::lonnavmaps::navmap;
                    923: 
                    924: =pod
                    925: 
                    926: lonnavmaps provides functions and objects for dealing with the compiled course hashes generated when a user enters the course, and also provides the Apache handler for the "Navigation Map" button.
                    927: 
                    928: =head1 navmap object: Encapsulating the compiled nav map
                    929: 
                    930: navmap is an object that encapsulates a compiled course map and provides a reasonable interface to it.
                    931: 
                    932: Most notably it provides a way to navigate the map sensibly and a flexible iterator that makes it easy to write various renderers based on nav maps.
                    933: 
                    934: You must obtain resource objects through the navmap object.
                    935: 
                    936: =head2 Methods
                    937: 
                    938: =over 4
                    939: 
1.70      bowersj2  940: =item * B<new>(navHashFile, parmHashFile, genCourseAndUserOptions, genMailDiscussStatus): Binds a new navmap object to the compiled nav map hash and parm hash given as filenames. genCourseAndUserOptions is a flag saying whether the course options and user options hash should be generated. This is for when you are using the parameters of the resources that require them; see documentation in resource object documentation. genMailDiscussStatus causes the nav map to retreive information about the email and discussion status of resources. Returns the navmap object if this is successful, or B<undef> if not. You must check for undef; errors will occur when you try to use the other methods otherwise.
1.51      bowersj2  941: 
                    942: =item * B<getIterator>(first, finish, filter, condition): See iterator documentation below.
                    943: 
                    944: =cut
                    945: 
                    946: use strict;
                    947: use GDBM_File;
                    948: 
                    949: sub new {
                    950:     # magic invocation to create a class instance
                    951:     my $proto = shift;
                    952:     my $class = ref($proto) || $proto;
                    953:     my $self = {};
                    954: 
                    955:     $self->{NAV_HASH_FILE} = shift;
                    956:     $self->{PARM_HASH_FILE} = shift;
                    957:     $self->{GENERATE_COURSE_USER_OPT} = shift;
1.55      bowersj2  958:     $self->{GENERATE_EMAIL_DISCUSS_STATUS} = shift;
1.51      bowersj2  959: 
1.101     bowersj2  960:     # Resource cache stores navmap resources as we reference them. We generate
1.51      bowersj2  961:     # them on-demand so we don't pay for creating resources unless we use them.
                    962:     $self->{RESOURCE_CACHE} = {};
                    963: 
                    964:     # Network failure flag, if we accessed the course or user opt and
                    965:     # failed
                    966:     $self->{NETWORK_FAILURE} = 0;
                    967: 
                    968:     # tie the nav hash
                    969:     my %navmaphash;
                    970:     if (!(tie(%navmaphash, 'GDBM_File', $self->{NAV_HASH_FILE},
                    971:               &GDBM_READER(), 0640))) {
                    972:         return undef;
                    973:     }
                    974:     
                    975:     my %parmhash;
                    976:     if (!(tie(%parmhash, 'GDBM_File', $self->{PARM_HASH_FILE},
                    977:               &GDBM_READER(), 0640)))
                    978:     {
1.66      bowersj2  979:         untie $self->{PARM_HASH};
1.51      bowersj2  980:         return undef;
                    981:     }
1.115     bowersj2  982: 
                    983:     # Now copy the hashes for speed (?)
                    984:     my %realnav; my %realparm;
                    985:     foreach (%navmaphash) { $realnav{$_} = $navmaphash{$_}; }
                    986:     foreach (%parmhash) { $realparm{$_} = $navmaphash{$_}; }
                    987:     $self->{NAV_HASH} = \%realnav;
                    988:     $self->{PARM_HASH} = \%realparm;
1.51      bowersj2  989: 
1.92      bowersj2  990:     bless($self);
1.115     bowersj2  991:     $self->untieHashes();
1.92      bowersj2  992:         
                    993:     return $self;
                    994: }
                    995: 
                    996: sub init {
1.93      bowersj2  997:     my $self = shift;
1.92      bowersj2  998: 
1.51      bowersj2  999:     # If the course opt hash and the user opt hash should be generated,
                   1000:     # generate them
                   1001:     if ($self->{GENERATE_COURSE_USER_OPT}) {
                   1002:         my $uname=$ENV{'user.name'};
                   1003:         my $udom=$ENV{'user.domain'};
                   1004:         my $uhome=$ENV{'user.home'};
                   1005:         my $cid=$ENV{'request.course.id'};
                   1006:         my $chome=$ENV{'course.'.$cid.'.home'};
                   1007:         my ($cdom,$cnum)=split(/\_/,$cid);
                   1008:         
                   1009:         my $userprefix=$uname.'_'.$udom.'_';
                   1010:         
1.99      bowersj2 1011:         my %courserdatas; my %useropt; my %courseopt; my %userrdatas;
1.51      bowersj2 1012:         unless ($uhome eq 'no_host') { 
                   1013: # ------------------------------------------------- Get coursedata (if present)
                   1014:             unless ((time-$courserdatas{$cid.'.last_cache'})<240) {
                   1015:                 my $reply=&Apache::lonnet::reply('dump:'.$cdom.':'.$cnum.
                   1016:                                                  ':resourcedata',$chome);
                   1017:                 if ($reply!~/^error\:/) {
                   1018:                     $courserdatas{$cid}=$reply;
                   1019:                     $courserdatas{$cid.'.last_cache'}=time;
                   1020:                 }
                   1021:                 # check to see if network failed
                   1022:                 elsif ( $reply=~/no.such.host/i || $reply=~/con.*lost/i )
                   1023:                 {
                   1024:                     $self->{NETWORK_FAILURE} = 1;
                   1025:                 }
                   1026:             }
                   1027:             foreach (split(/\&/,$courserdatas{$cid})) {
                   1028:                 my ($name,$value)=split(/\=/,$_);
                   1029:                 $courseopt{$userprefix.&Apache::lonnet::unescape($name)}=
                   1030:                     &Apache::lonnet::unescape($value);
                   1031:             }
                   1032: # --------------------------------------------------- Get userdata (if present)
                   1033:             unless ((time-$userrdatas{$uname.'___'.$udom.'.last_cache'})<240) {
                   1034:                 my $reply=&Apache::lonnet::reply('dump:'.$udom.':'.$uname.':resourcedata',$uhome);
                   1035:                 if ($reply!~/^error\:/) {
                   1036:                     $userrdatas{$uname.'___'.$udom}=$reply;
                   1037:                     $userrdatas{$uname.'___'.$udom.'.last_cache'}=time;
                   1038:                 }
                   1039:                 # check to see if network failed
                   1040:                 elsif ( $reply=~/no.such.host/i || $reply=~/con.*lost/i )
                   1041:                 {
                   1042:                     $self->{NETWORK_FAILURE} = 1;
                   1043:                 }
                   1044:             }
                   1045:             foreach (split(/\&/,$userrdatas{$uname.'___'.$udom})) {
                   1046:                 my ($name,$value)=split(/\=/,$_);
                   1047:                 $useropt{$userprefix.&Apache::lonnet::unescape($name)}=
                   1048:                     &Apache::lonnet::unescape($value);
                   1049:             }
1.55      bowersj2 1050:             $self->{COURSE_OPT} = \%courseopt;
                   1051:             $self->{USER_OPT} = \%useropt;
1.51      bowersj2 1052:         }
                   1053:     }   
                   1054: 
1.55      bowersj2 1055:     if ($self->{GENERATE_EMAIL_DISCUSS_STATUS}) {
                   1056:         my $cid=$ENV{'request.course.id'};
                   1057:         my ($cdom,$cnum)=split(/\_/,$cid);
                   1058:         
                   1059:         my %emailstatus = &Apache::lonnet::dump('email_status');
1.56      bowersj2 1060:         my $logoutTime = $emailstatus{'logout'};
                   1061:         my $courseLeaveTime = $emailstatus{'logout_'.$ENV{'request.course.id'}};
1.55      bowersj2 1062:         $self->{LAST_CHECK} = ($courseLeaveTime > $logoutTime ?
                   1063:                                $courseLeaveTime : $logoutTime);
1.56      bowersj2 1064:         my %discussiontime = &Apache::lonnet::dump('discussiontimes', 
1.55      bowersj2 1065:                                                    $cdom, $cnum);
                   1066:         my %feedback=();
                   1067:         my %error=();
                   1068:         my $keys = &Apache::lonnet::reply('keys:'.
                   1069:                                           $ENV{'user.domain'}.':'.
                   1070:                                           $ENV{'user.name'}.':nohist_email',
                   1071:                                           $ENV{'user.home'});
                   1072: 
                   1073:         foreach my $msgid (split(/\&/, $keys)) {
                   1074:             $msgid=&Apache::lonnet::unescape($msgid);
                   1075:             my $plain=&Apache::lonnet::unescape(&Apache::lonnet::unescape($msgid));
                   1076:             if ($plain=~/(Error|Feedback) \[([^\]]+)\]/) {
                   1077:                 my ($what,$url)=($1,$2);
                   1078:                 my %status=
                   1079:                     &Apache::lonnet::get('email_status',[$msgid]);
                   1080:                 if ($status{$msgid}=~/^error\:/) { 
                   1081:                     $status{$msgid}=''; 
                   1082:                 }
                   1083:                 
                   1084:                 if (($status{$msgid} eq 'new') || 
                   1085:                     (!$status{$msgid})) { 
                   1086:                     if ($what eq 'Error') {
                   1087:                         $error{$url}.=','.$msgid; 
                   1088:                     } else {
                   1089:                         $feedback{$url}.=','.$msgid;
                   1090:                     }
                   1091:                 }
                   1092:             }
                   1093:         }
                   1094:         
                   1095:         $self->{FEEDBACK} = \%feedback;
                   1096:         $self->{ERROR_MSG} = \%error; # what is this? JB
                   1097:         $self->{DISCUSSION_TIME} = \%discussiontime;
                   1098:         $self->{EMAIL_STATUS} = \%emailstatus;
                   1099:         
                   1100:     }    
1.84      bowersj2 1101: 
                   1102:     $self->{PARM_CACHE} = {};
1.55      bowersj2 1103: }
1.51      bowersj2 1104: 
1.115     bowersj2 1105: # Internal function: Takes a key to look up in the nav hash and implements internal
                   1106: # memory caching of that key.
                   1107: sub navhash {
                   1108:     my $self = shift; my $key = shift;
                   1109:     return $self->{NAV_HASH}->{$key};
                   1110: }
                   1111: 
1.55      bowersj2 1112: # Checks to see if coursemap is defined, matching test in old lonnavmaps
                   1113: sub courseMapDefined {
                   1114:     my $self = shift;
                   1115:     my $uri = &Apache::lonnet::clutter($ENV{'request.course.uri'});
                   1116: 
1.115     bowersj2 1117:     my $firstres = $self->navhash("map_start_$uri");
                   1118:     my $lastres = $self->navhash("map_finish_$uri");
1.55      bowersj2 1119:     return $firstres && $lastres;
1.51      bowersj2 1120: }
                   1121: 
                   1122: sub getIterator {
                   1123:     my $self = shift;
1.98      bowersj2 1124:     my $iterator = Apache::lonnavmaps::iterator->new($self, shift, shift,
1.101     bowersj2 1125:                                                      shift, undef, shift);
1.51      bowersj2 1126:     return $iterator;
                   1127: }
                   1128: 
                   1129: # unties the hash when done
                   1130: sub untieHashes {
                   1131:     my $self = shift;
1.60      bowersj2 1132:     untie %{$self->{NAV_HASH}} if ($self->{HASH_TIED});
                   1133:     untie %{$self->{PARM_HASH}} if ($self->{HASH_TIED});
1.51      bowersj2 1134:     $self->{HASH_TIED} = 0;
                   1135: }
                   1136: 
                   1137: # when the object is destroyed, be sure to untie all the hashes we tied.
                   1138: sub DESTROY {
                   1139:     my $self = shift;
                   1140:     $self->untieHashes();
                   1141: }
                   1142: 
1.59      bowersj2 1143: # Private function: Does the given resource (as a symb string) have
                   1144: # current discussion? Returns 0 if chat/mail data not extracted.
                   1145: sub hasDiscussion {
                   1146:     my $self = shift;
                   1147:     my $symb = shift;
                   1148:     if (!defined($self->{DISCUSSION_TIME})) { return 0; }
                   1149: 
                   1150:     return $self->{DISCUSSION_TIME}->{$symb} >
1.66      bowersj2 1151:            $self->{LAST_CHECK};
1.59      bowersj2 1152: }
                   1153: 
                   1154: # Private function: Does the given resource (as a symb string) have
                   1155: # current feedback? Returns the string in the feedback hash, which
                   1156: # will be false if it does not exist.
                   1157: sub getFeedback { 
                   1158:     my $self = shift;
                   1159:     my $symb = shift;
                   1160: 
                   1161:     if (!defined($self->{FEEDBACK})) { return ""; }
                   1162:     
                   1163:     return $self->{FEEDBACK}->{$symb};
                   1164: }
                   1165: 
1.51      bowersj2 1166: =pod
                   1167: 
                   1168: =item * B<getById>(id): Based on the ID of the resource (1.1, 3.2, etc.), get a resource object for that resource. This method, or other methods that use it (as in the resource object) is the only proper way to obtain a resource object.
                   1169: 
                   1170: =cut
                   1171: 
                   1172: # The strategy here is to cache the resource objects, and only construct them
                   1173: # as we use them. The real point is to prevent reading any more from the tied
                   1174: # hash then we have to, which should hopefully alleviate speed problems.
                   1175: # Caching is just an incidental detail I throw in because it makes sense.
                   1176: 
                   1177: sub getById {
                   1178:     my $self = shift;
                   1179:     my $id = shift;
                   1180: 
                   1181:     if (defined ($self->{RESOURCE_CACHE}->{$id}))
                   1182:     {
                   1183:         return $self->{RESOURCE_CACHE}->{$id};
                   1184:     }
                   1185: 
                   1186:     # resource handles inserting itself into cache.
                   1187:     return Apache::lonnavmaps::resource->new($self, $id);
                   1188: }
                   1189: 
                   1190: =pod
                   1191: 
                   1192: =item * B<firstResource>(): Returns a resource object reference corresponding to the first resource in the navmap.
                   1193: 
                   1194: =cut
                   1195: 
                   1196: sub firstResource {
                   1197:     my $self = shift;
1.115     bowersj2 1198:     my $firstResource = $self->navhash('map_start_' .
                   1199:                      &Apache::lonnet::clutter($ENV{'request.course.uri'}));
1.51      bowersj2 1200:     return $self->getById($firstResource);
                   1201: }
                   1202: 
                   1203: =pod
                   1204: 
                   1205: =item * B<finishResource>(): Returns a resource object reference corresponding to the last resource in the navmap.
                   1206: 
                   1207: =cut
                   1208: 
                   1209: sub finishResource {
                   1210:     my $self = shift;
1.115     bowersj2 1211:     my $firstResource = $self->navhash('map_finish_' .
                   1212:                      &Apache::lonnet::clutter($ENV{'request.course.uri'}));
1.51      bowersj2 1213:     return $self->getById($firstResource);
                   1214: }
                   1215: 
1.101     bowersj2 1216: # Parmval reads the parm hash and cascades the lookups. parmval_real does
                   1217: # the actual lookup; parmval caches the results.
1.51      bowersj2 1218: sub parmval {
                   1219:     my $self = shift;
                   1220:     my ($what,$symb)=@_;
1.84      bowersj2 1221:     my $hashkey = $what."|||".$symb;
                   1222: 
                   1223:     if (defined($self->{PARM_CACHE}->{$hashkey})) {
                   1224:         return $self->{PARM_CACHE}->{$hashkey};
                   1225:     }
                   1226: 
                   1227:     my $result = $self->parmval_real($what, $symb);
                   1228:     $self->{PARM_CACHE}->{$hashkey} = $result;
                   1229:     return $result;
                   1230: }
                   1231: 
                   1232: sub parmval_real {
                   1233:     my $self = shift;
                   1234:     my ($what,$symb) = @_;
                   1235: 
1.51      bowersj2 1236:     my $cid=$ENV{'request.course.id'};
                   1237:     my $csec=$ENV{'request.course.sec'};
                   1238:     my $uname=$ENV{'user.name'};
                   1239:     my $udom=$ENV{'user.domain'};
                   1240: 
                   1241:     unless ($symb) { return ''; }
                   1242:     my $result='';
                   1243: 
                   1244:     my ($mapname,$id,$fn)=split(/\_\_\_/,$symb);
                   1245: 
                   1246: # ----------------------------------------------------- Cascading lookup scheme
                   1247:     my $rwhat=$what;
                   1248:     $what=~s/^parameter\_//;
                   1249:     $what=~s/\_/\./;
                   1250: 
                   1251:     my $symbparm=$symb.'.'.$what;
                   1252:     my $mapparm=$mapname.'___(all).'.$what;
                   1253:     my $usercourseprefix=$uname.'_'.$udom.'_'.$cid;
                   1254: 
                   1255:     my $seclevel= $usercourseprefix.'.['.$csec.'].'.$what;
                   1256:     my $seclevelr=$usercourseprefix.'.['.$csec.'].'.$symbparm;
                   1257:     my $seclevelm=$usercourseprefix.'.['.$csec.'].'.$mapparm;
                   1258: 
                   1259:     my $courselevel= $usercourseprefix.'.'.$what;
                   1260:     my $courselevelr=$usercourseprefix.'.'.$symbparm;
                   1261:     my $courselevelm=$usercourseprefix.'.'.$mapparm;
                   1262: 
                   1263:     my $useropt = $self->{USER_OPT};
                   1264:     my $courseopt = $self->{COURSE_OPT};
                   1265:     my $parmhash = $self->{PARM_HASH};
                   1266: 
                   1267: # ---------------------------------------------------------- first, check user
                   1268:     if ($uname and defined($useropt)) {
1.57      albertel 1269:         if (defined($$useropt{$courselevelr})) { return $$useropt{$courselevelr}; }
                   1270:         if (defined($$useropt{$courselevelm})) { return $$useropt{$courselevelm}; }
                   1271:         if (defined($$useropt{$courselevel})) { return $$useropt{$courselevel}; }
1.51      bowersj2 1272:     }
                   1273: 
                   1274: # ------------------------------------------------------- second, check course
                   1275:     if ($csec and defined($courseopt)) {
1.57      albertel 1276:         if (defined($$courseopt{$seclevelr})) { return $$courseopt{$seclevelr}; }
                   1277:         if (defined($$courseopt{$seclevelm})) { return $$courseopt{$seclevelm}; }
                   1278:         if (defined($$courseopt{$seclevel})) { return $$courseopt{$seclevel}; }
1.51      bowersj2 1279:     }
                   1280: 
                   1281:     if (defined($courseopt)) {
1.57      albertel 1282:         if (defined($$courseopt{$courselevelr})) { return $$courseopt{$courselevelr}; }
                   1283:         if (defined($$courseopt{$courselevelm})) { return $$courseopt{$courselevelm}; }
                   1284:         if (defined($$courseopt{$courselevel})) { return $$courseopt{$courselevel}; }
1.51      bowersj2 1285:     }
                   1286: 
                   1287: # ----------------------------------------------------- third, check map parms
                   1288: 
                   1289:     my $thisparm=$$parmhash{$symbparm};
1.57      albertel 1290:     if (defined($thisparm)) { return $thisparm; }
1.51      bowersj2 1291: 
                   1292: # ----------------------------------------------------- fourth , check default
                   1293: 
                   1294:     my $default=&Apache::lonnet::metadata($fn,$rwhat.'.default');
1.57      albertel 1295:     if (defined($default)) { return $default}
1.51      bowersj2 1296: 
                   1297: # --------------------------------------------------- fifth , cascade up parts
                   1298: 
                   1299:     my ($space,@qualifier)=split(/\./,$rwhat);
                   1300:     my $qualifier=join('.',@qualifier);
                   1301:     unless ($space eq '0') {
                   1302:         my ($part,$id)=split(/\_/,$space);
                   1303:         if ($id) {
                   1304:             my $partgeneral=$self->parmval($part.".$qualifier",$symb);
1.57      albertel 1305:             if (defined($partgeneral)) { return $partgeneral; }
1.51      bowersj2 1306:         } else {
                   1307:             my $resourcegeneral=$self->parmval("0.$qualifier",$symb);
1.57      albertel 1308:             if (defined($resourcegeneral)) { return $resourcegeneral; }
1.51      bowersj2 1309:         }
                   1310:     }
                   1311:     return '';
                   1312: }
                   1313: 
                   1314: 
                   1315: 1;
                   1316: 
                   1317: package Apache::lonnavmaps::iterator;
                   1318: 
                   1319: =pod
                   1320: 
                   1321: =back
                   1322: 
                   1323: =head1 navmap Iterator
                   1324: 
                   1325: An I<iterator> encapsulates the logic required to traverse a data structure. navmap uses an iterator to traverse the course map according to the criteria you wish to use.
                   1326: 
                   1327: To obtain an iterator, call the B<getIterator>() function of a B<navmap> object. (Do not instantiate Apache::lonnavmaps::iterator directly.) This will return a reference to the iterator:
                   1328: 
                   1329: C<my $resourceIterator = $navmap-E<gt>getIterator();>
                   1330: 
                   1331: To get the next thing from the iterator, call B<next>:
                   1332: 
                   1333: C<my $nextThing = $resourceIterator-E<gt>next()>
                   1334: 
                   1335: getIterator behaves as follows:
                   1336: 
                   1337: =over 4
                   1338: 
1.116     bowersj2 1339: =item * B<getIterator>(firstResource, finishResource, filterHash, condition, forceTop): All parameters are optional. firstResource is a resource reference corresponding to where the iterator should start. It defaults to navmap->firstResource() for the corresponding nav map. finishResource corresponds to where you want the iterator to end, defaulting to navmap->finishResource(). filterHash is a hash used as a set containing strings representing the resource IDs, defaulting to empty. Condition is a 1 or 0 that sets what to do with the filter hash: If a 0, then only resource that exist IN the filterHash will be recursed on. If it is a 1, only resources NOT in the filterHash will be recursed on. Defaults to 0. forceTop is a boolean value. If it is false (default), the iterator will only return the first level of map that is not just a single, 'redirecting' map. If true, the iterator will return all information, starting with the top-level map, regardless of content.
1.51      bowersj2 1340: 
1.101     bowersj2 1341: Thus, by default, only top-level resources will be shown. Change the condition to a 1 without changing the hash, and all resources will be shown. Changing the condition to 1 and including some values in the hash will allow you to selectively suppress parts of the navmap, while leaving it on 0 and adding things to the hash will allow you to selectively add parts of the nav map. See the handler code for examples.
1.51      bowersj2 1342: 
                   1343: The iterator will return either a reference to a resource object, or a token representing something in the map, such as the beginning of a new branch. The possible tokens are:
                   1344: 
                   1345: =over 4
                   1346: 
1.70      bowersj2 1347: =item * BEGIN_MAP: A new map is being recursed into. This is returned I<after> the map resource itself is returned.
                   1348: 
                   1349: =item * END_MAP: The map is now done.
                   1350: 
                   1351: =item * BEGIN_BRANCH: A branch is now starting. The next resource returned will be the first in that branch.
                   1352: 
                   1353: =item * END_BRANCH: The branch is now done.
1.51      bowersj2 1354: 
                   1355: =back
                   1356: 
1.70      bowersj2 1357: The tokens are retreivable via methods on the iterator object, i.e., $iterator->END_MAP.
                   1358: 
1.116     bowersj2 1359: Maps can contain empty resources. The iterator will automatically skip over such resources, but will still treat the structure correctly. Thus, a complicated map with several branches, but consisting entirely of empty resources except for one beginning or ending resource, will cause a lot of BRANCH_STARTs and BRANCH_ENDs, but only one resource will be returned.
                   1360: 
1.70      bowersj2 1361: =back
1.51      bowersj2 1362: 
                   1363: =cut
                   1364: 
                   1365: # Here are the tokens for the iterator:
                   1366: 
                   1367: sub BEGIN_MAP { return 1; }    # begining of a new map
                   1368: sub END_MAP { return 2; }      # end of the map
                   1369: sub BEGIN_BRANCH { return 3; } # beginning of a branch
                   1370: sub END_BRANCH { return 4; }   # end of a branch
1.89      bowersj2 1371: sub FORWARD { return 1; }      # go forward
                   1372: sub BACKWARD { return 2; }
1.51      bowersj2 1373: 
1.96      bowersj2 1374: sub min {
                   1375:     (my $a, my $b) = @_;
                   1376:     if ($a < $b) { return $a; } else { return $b; }
                   1377: }
                   1378: 
1.107     bowersj2 1379: # In the CVS repository, documentation of this algorithm is included 
                   1380: # in /doc/lonnavdocs, as a PDF and .tex source. Markers like **1**
                   1381: # will reference the same location in the text as the part of the
                   1382: # algorithm is running through.
                   1383: 
1.94      bowersj2 1384: sub new {
                   1385:     # magic invocation to create a class instance
                   1386:     my $proto = shift;
                   1387:     my $class = ref($proto) || $proto;
                   1388:     my $self = {};
                   1389: 
                   1390:     $self->{NAV_MAP} = shift;
                   1391:     return undef unless ($self->{NAV_MAP});
                   1392: 
                   1393:     # Handle the parameters
                   1394:     $self->{FIRST_RESOURCE} = shift || $self->{NAV_MAP}->firstResource();
                   1395:     $self->{FINISH_RESOURCE} = shift || $self->{NAV_MAP}->finishResource();
                   1396: 
                   1397:     # If the given resources are just the ID of the resource, get the
                   1398:     # objects
                   1399:     if (!ref($self->{FIRST_RESOURCE})) { $self->{FIRST_RESOURCE} = 
                   1400:              $self->{NAV_MAP}->getById($self->{FIRST_RESOURCE}); }
                   1401:     if (!ref($self->{FINISH_RESOURCE})) { $self->{FINISH_RESOURCE} = 
                   1402:              $self->{NAV_MAP}->getById($self->{FINISH_RESOURCE}); }
                   1403: 
                   1404:     $self->{FILTER} = shift;
                   1405: 
                   1406:     # A hash, used as a set, of resource already seen
                   1407:     $self->{ALREADY_SEEN} = shift;
                   1408:     if (!defined($self->{ALREADY_SEEN})) { $self->{ALREADY_SEEN} = {} };
                   1409:     $self->{CONDITION} = shift;
                   1410: 
1.116     bowersj2 1411:     # Do we want to automatically follow "redirection" maps?
                   1412:     $self->{FORCE_TOP} = shift;
                   1413: 
1.94      bowersj2 1414:     # Now, we need to pre-process the map, by walking forward and backward
                   1415:     # over the parts of the map we're going to look at.
1.96      bowersj2 1416: 
1.97      bowersj2 1417:     # The processing steps are exactly the same, except for a few small 
                   1418:     # changes, so I bundle those up in the following list of two elements:
                   1419:     # (direction_to_iterate, VAL_name, next_resource_method_to_call,
                   1420:     # first_resource).
                   1421:     # This prevents writing nearly-identical code twice.
                   1422:     my @iterations = ( [FORWARD(), 'TOP_DOWN_VAL', 'getNext', 
                   1423:                         'FIRST_RESOURCE'],
                   1424:                        [BACKWARD(), 'BOT_UP_VAL', 'getPrevious', 
                   1425:                         'FINISH_RESOURCE'] );
                   1426: 
1.98      bowersj2 1427:     my $maxDepth = 0; # tracks max depth
                   1428: 
1.116     bowersj2 1429:     # If there is only one resource in this map, and it's a map, we
                   1430:     # want to remember that, so the user can ask for the first map
                   1431:     # that isn't just a redirector.
                   1432:     my $resource; my $resourceCount = 0;
                   1433: 
1.107     bowersj2 1434:     # **1**
                   1435: 
1.97      bowersj2 1436:     foreach my $pass (@iterations) {
                   1437:         my $direction = $pass->[0];
                   1438:         my $valName = $pass->[1];
                   1439:         my $nextResourceMethod = $pass->[2];
                   1440:         my $firstResourceName = $pass->[3];
                   1441: 
                   1442:         my $iterator = Apache::lonnavmaps::DFSiterator->new($self->{NAV_MAP}, 
                   1443:                                                             $self->{FIRST_RESOURCE},
                   1444:                                                             $self->{FINISH_RESOURCE},
                   1445:                                                             {}, undef, 0, $direction);
1.96      bowersj2 1446:     
1.97      bowersj2 1447:         # prime the recursion
                   1448:         $self->{$firstResourceName}->{DATA}->{$valName} = 0;
1.98      bowersj2 1449:         my $depth = 0;
1.97      bowersj2 1450:         $iterator->next();
                   1451:         my $curRes = $iterator->next();
1.98      bowersj2 1452:         while ($depth > -1) {
1.97      bowersj2 1453:             if ($curRes == $iterator->BEGIN_MAP()) { $depth++; }
                   1454:             if ($curRes == $iterator->END_MAP()) { $depth--; }
1.96      bowersj2 1455:         
1.97      bowersj2 1456:             if (ref($curRes)) {
1.116     bowersj2 1457:                 # If there's only one resource, this will save it
1.117     bowersj2 1458:                 # we have to filter empty resources from consideration here,
                   1459:                 # or even "empty", redirecting maps have two (start & finish)
                   1460:                 # or three (start, finish, plus redirector)
                   1461:                 if($direction == FORWARD && $curRes->src()) { 
                   1462:                     $resource = $curRes; $resourceCount++; 
                   1463:                 }
1.97      bowersj2 1464:                 my $resultingVal = $curRes->{DATA}->{$valName};
                   1465:                 my $nextResources = $curRes->$nextResourceMethod();
1.116     bowersj2 1466:                 my $nextCount = scalar(@{$nextResources});
1.104     bowersj2 1467: 
1.116     bowersj2 1468:                 if ($nextCount == 1) { # **3**
1.97      bowersj2 1469:                     my $current = $nextResources->[0]->{DATA}->{$valName} || 999999999;
                   1470:                     $nextResources->[0]->{DATA}->{$valName} = min($resultingVal, $current);
                   1471:                 }
                   1472:                 
1.116     bowersj2 1473:                 if ($nextCount > 1) { # **4**
1.97      bowersj2 1474:                     foreach my $res (@{$nextResources}) {
                   1475:                         my $current = $res->{DATA}->{$valName} || 999999999;
                   1476:                         $res->{DATA}->{$valName} = min($current, $resultingVal + 1);
                   1477:                     }
                   1478:                 }
                   1479:             }
1.96      bowersj2 1480:             
1.107     bowersj2 1481:             # Assign the final val (**2**)
1.97      bowersj2 1482:             if (ref($curRes) && $direction == BACKWARD()) {
1.98      bowersj2 1483:                 my $finalDepth = min($curRes->{DATA}->{TOP_DOWN_VAL},
                   1484:                                      $curRes->{DATA}->{BOT_UP_VAL});
                   1485:                 
                   1486:                 $curRes->{DATA}->{DISPLAY_DEPTH} = $finalDepth;
                   1487:                 if ($finalDepth > $maxDepth) {$maxDepth = $finalDepth;}
                   1488:                 }
1.97      bowersj2 1489:             $curRes = $iterator->next();
1.96      bowersj2 1490:         }
                   1491:     }
1.94      bowersj2 1492: 
1.116     bowersj2 1493:     # Check: Was this only one resource, a map?
                   1494:     if ($resourceCount == 1 && $resource->is_map() && !$self->{FORCE_TOP}) { 
                   1495:         my $firstResource = $resource->map_start();
                   1496:         my $finishResource = $resource->map_finish();
                   1497:         return 
                   1498:             Apache::lonnavmaps::iterator->new($self->{NAV_MAP}, $firstResource,
                   1499:                                               $finishResource, $self->{FILTER},
                   1500:                                               $self->{ALREADY_SEEN}, 
                   1501:                                               $self->{CONDITION}, 0);
                   1502:         
                   1503:     }
                   1504: 
1.98      bowersj2 1505:     # Set up some bookkeeping information.
                   1506:     $self->{CURRENT_DEPTH} = 0;
                   1507:     $self->{MAX_DEPTH} = $maxDepth;
                   1508:     $self->{STACK} = [];
                   1509:     $self->{RECURSIVE_ITERATOR_FLAG} = 0;
                   1510: 
                   1511:     for (my $i = 0; $i <= $self->{MAX_DEPTH}; $i++) {
                   1512:         push @{$self->{STACK}}, [];
                   1513:     }
                   1514: 
1.107     bowersj2 1515:     # Prime the recursion w/ the first resource **5**
1.98      bowersj2 1516:     push @{$self->{STACK}->[0]}, $self->{FIRST_RESOURCE};
                   1517:     $self->{ALREADY_SEEN}->{$self->{FIRST_RESOURCE}->{ID}} = 1;
                   1518: 
                   1519:     bless ($self);
                   1520: 
                   1521:     return $self;
                   1522: }
                   1523: 
                   1524: sub next {
                   1525:     my $self = shift;
                   1526: 
                   1527:     if ($self->{RECURSIVE_ITERATOR_FLAG}) {
                   1528:         # grab the next from the recursive iterator 
                   1529:         my $next = $self->{RECURSIVE_ITERATOR}->next();
                   1530: 
                   1531:         # is it a begin or end map? If so, update the depth
                   1532:         if ($next == BEGIN_MAP() ) { $self->{RECURSIVE_DEPTH}++; }
                   1533:         if ($next == END_MAP() ) { $self->{RECURSIVE_DEPTH}--; }
                   1534: 
                   1535:         # Are we back at depth 0? If so, stop recursing
                   1536:         if ($self->{RECURSIVE_DEPTH} == 0) {
                   1537:             $self->{RECURSIVE_ITERATOR_FLAG} = 0;
                   1538:         }
                   1539: 
                   1540:         return $next;
                   1541:     }
                   1542: 
                   1543:     if (defined($self->{FORCE_NEXT})) {
                   1544:         my $tmp = $self->{FORCE_NEXT};
                   1545:         $self->{FORCE_NEXT} = undef;
                   1546:         return $tmp;
                   1547:     }
                   1548: 
                   1549:     # Have we not yet begun? If not, return BEGIN_MAP and
                   1550:     # remember we've started.
                   1551:     if ( !$self->{STARTED} ) { 
                   1552:         $self->{STARTED} = 1;
                   1553:         return $self->BEGIN_MAP();
                   1554:     }
                   1555: 
                   1556:     # Here's the guts of the iterator.
                   1557:     
                   1558:     # Find the next resource, if any.
                   1559:     my $found = 0;
                   1560:     my $i = $self->{MAX_DEPTH};
                   1561:     my $newDepth;
                   1562:     my $here;
                   1563:     while ( $i >= 0 && !$found ) {
1.107     bowersj2 1564:         if ( scalar(@{$self->{STACK}->[$i]}) > 0 ) { # **6**
                   1565:             $here = pop @{$self->{STACK}->[$i]}; # **7**
1.98      bowersj2 1566:             $found = 1;
                   1567:             $newDepth = $i;
                   1568:         }
                   1569:         $i--;
                   1570:     }
                   1571: 
                   1572:     # If we still didn't find anything, we're done.
                   1573:     if ( !$found ) {
                   1574:         # We need to get back down to the correct branch depth
                   1575:         if ( $self->{CURRENT_DEPTH} > 0 ) {
                   1576:             $self->{CURRENT_DEPTH}--;
                   1577:             return END_BRANCH();
                   1578:         } else {
                   1579:             return END_MAP();
                   1580:         }
                   1581:     }
                   1582: 
1.104     bowersj2 1583:     # If this is not a resource, it must be an END_BRANCH marker we want
                   1584:     # to return directly.
1.107     bowersj2 1585:     if (!ref($here)) { # **8**
1.104     bowersj2 1586:         if ($here == END_BRANCH()) { # paranoia, in case of later extension
                   1587:             $self->{CURRENT_DEPTH}--;
                   1588:             return $here;
                   1589:         }
                   1590:     }
                   1591: 
                   1592:     # Otherwise, it is a resource and it's safe to store in $self->{HERE}
                   1593:     $self->{HERE} = $here;
                   1594: 
1.98      bowersj2 1595:     # Get to the right level
                   1596:     if ( $self->{CURRENT_DEPTH} > $newDepth ) {
                   1597:         push @{$self->{STACK}->[$newDepth]}, $here;
                   1598:         $self->{CURRENT_DEPTH}--;
                   1599:         return END_BRANCH();
                   1600:     }
                   1601:     if ( $self->{CURRENT_DEPTH} < $newDepth) {
                   1602:         push @{$self->{STACK}->[$newDepth]}, $here;
                   1603:         $self->{CURRENT_DEPTH}++;
                   1604:         return BEGIN_BRANCH();
                   1605:     }
                   1606: 
                   1607:     # If we made it here, we have the next resource, and we're at the
                   1608:     # right branch level. So let's examine the resource for where
                   1609:     # we can get to from here.
                   1610: 
                   1611:     # So we need to look at all the resources we can get to from here,
                   1612:     # categorize them if we haven't seen them, remember if we have a new
                   1613:     my $nextUnfiltered = $here->getNext();
1.104     bowersj2 1614:     my $maxDepthAdded = -1;
                   1615:     
1.98      bowersj2 1616:     for (@$nextUnfiltered) {
                   1617:         if (!defined($self->{ALREADY_SEEN}->{$_->{ID}})) {
1.104     bowersj2 1618:             my $depth = $_->{DATA}->{DISPLAY_DEPTH};
                   1619:             push @{$self->{STACK}->[$depth]}, $_;
1.98      bowersj2 1620:             $self->{ALREADY_SEEN}->{$_->{ID}} = 1;
1.104     bowersj2 1621:             if ($maxDepthAdded < $depth) { $maxDepthAdded = $depth; }
1.98      bowersj2 1622:         }
                   1623:     }
1.104     bowersj2 1624: 
                   1625:     # Is this the end of a branch? If so, all of the resources examined above
                   1626:     # led to lower levels then the one we are currently at, so we push a END_BRANCH
                   1627:     # marker onto the stack so we don't forget.
                   1628:     # Example: For the usual A(BC)(DE)F case, when the iterator goes down the
                   1629:     # BC branch and gets to C, it will see F as the only next resource, but it's
                   1630:     # one level lower. Thus, this is the end of the branch, since there are no
                   1631:     # more resources added to this level or above.
1.111     bowersj2 1632:     # We don't do this if the examined resource is the finish resource,
                   1633:     # because the condition given above is true, but the "END_MAP" will
                   1634:     # take care of things and we should already be at depth 0.
1.104     bowersj2 1635:     my $isEndOfBranch = $maxDepthAdded < $self->{CURRENT_DEPTH};
1.111     bowersj2 1636:     if ($isEndOfBranch && $here != $self->{FINISH_RESOURCE}) { # **9**
1.104     bowersj2 1637:         push @{$self->{STACK}->[$self->{CURRENT_DEPTH}]}, END_BRANCH();
                   1638:     }
                   1639: 
1.98      bowersj2 1640:     # That ends the main iterator logic. Now, do we want to recurse
                   1641:     # down this map (if this resource is a map)?
                   1642:     if ($self->{HERE}->is_map() &&
                   1643:         (defined($self->{FILTER}->{$self->{HERE}->map_pc()}) xor $self->{CONDITION})) {
                   1644:         $self->{RECURSIVE_ITERATOR_FLAG} = 1;
                   1645:         my $firstResource = $self->{HERE}->map_start();
                   1646:         my $finishResource = $self->{HERE}->map_finish();
                   1647: 
                   1648:         $self->{RECURSIVE_ITERATOR} = 
                   1649:             Apache::lonnavmaps::iterator->new($self->{NAV_MAP}, $firstResource,
                   1650:                                               $finishResource, $self->{FILTER},
                   1651:                                               $self->{ALREADY_SEEN}, $self->{CONDITION});
                   1652:     }
                   1653: 
1.116     bowersj2 1654:     # If this is a blank resource, don't actually return it.
1.117     bowersj2 1655:     # Should you ever find you need it, make sure to add an option to the code
                   1656:     #  that you can use; other things depend on this behavior.
1.116     bowersj2 1657:     if (!$self->{HERE}->src()) {
                   1658:         return $self->next();
                   1659:     }
                   1660: 
1.98      bowersj2 1661:     return $self->{HERE};
                   1662: 
                   1663: }
                   1664: 
                   1665: =pod
                   1666: 
                   1667: The other method available on the iterator is B<getStack>, which returns an array populated with the current 'stack' of maps, as references to the resource objects. Example: This is useful when making the navigation map, as we need to check whether we are under a page map to see if we need to link directly to the resource, or to the page. The first elements in the array will correspond to the top of the stack (most inclusive map).
                   1668: 
                   1669: =cut
                   1670: 
                   1671: sub getStack {
                   1672:     my $self=shift;
                   1673: 
                   1674:     my @stack;
                   1675: 
                   1676:     $self->populateStack(\@stack);
                   1677: 
                   1678:     return \@stack;
                   1679: }
                   1680: 
                   1681: # Private method: Calls the iterators recursively to populate the stack.
                   1682: sub populateStack {
                   1683:     my $self=shift;
                   1684:     my $stack = shift;
                   1685: 
                   1686:     push @$stack, $self->{HERE} if ($self->{HERE});
                   1687: 
                   1688:     if ($self->{RECURSIVE_ITERATOR_FLAG}) {
                   1689:         $self->{RECURSIVE_ITERATOR}->populateStack($stack);
                   1690:     }
1.94      bowersj2 1691: }
                   1692: 
                   1693: 1;
                   1694: 
                   1695: package Apache::lonnavmaps::DFSiterator;
                   1696: 
1.100     bowersj2 1697: # Not documented in the perldoc: This is a simple iterator that just walks
                   1698: #  through the nav map and presents the resources in a depth-first search
                   1699: #  fashion, ignorant of conditionals, randomized resources, etc. It presents
                   1700: #  BEGIN_MAP and END_MAP, but does not understand branches at all. It is
                   1701: #  useful for pre-processing of some kind, and is in fact used by the main
                   1702: #  iterator that way, but that's about it.
                   1703: # One could imagine merging this into the init routine of the main iterator,
                   1704: #  but this might as well be left seperate, since it is possible some other
                   1705: #  use might be found for it. - Jeremy
1.94      bowersj2 1706: 
1.117     bowersj2 1707: # Unlike the main iterator, this DOES return all resources, even blank ones.
                   1708: #  The main iterator needs them to correctly preprocess the map.
                   1709: 
1.94      bowersj2 1710: sub BEGIN_MAP { return 1; }    # begining of a new map
                   1711: sub END_MAP { return 2; }      # end of the map
                   1712: sub FORWARD { return 1; }      # go forward
                   1713: sub BACKWARD { return 2; }
                   1714: 
1.100     bowersj2 1715: # Params: Nav map ref, first resource id/ref, finish resource id/ref,
                   1716: #         filter hash ref (or undef), already seen hash or undef, condition
                   1717: #         (as in main iterator), direction FORWARD or BACKWARD (undef->forward).
1.51      bowersj2 1718: sub new {
                   1719:     # magic invocation to create a class instance
                   1720:     my $proto = shift;
                   1721:     my $class = ref($proto) || $proto;
                   1722:     my $self = {};
                   1723: 
                   1724:     $self->{NAV_MAP} = shift;
                   1725:     return undef unless ($self->{NAV_MAP});
                   1726: 
                   1727:     $self->{FIRST_RESOURCE} = shift || $self->{NAV_MAP}->firstResource();
                   1728:     $self->{FINISH_RESOURCE} = shift || $self->{NAV_MAP}->finishResource();
                   1729: 
                   1730:     # If the given resources are just the ID of the resource, get the
                   1731:     # objects
                   1732:     if (!ref($self->{FIRST_RESOURCE})) { $self->{FIRST_RESOURCE} = 
                   1733:              $self->{NAV_MAP}->getById($self->{FIRST_RESOURCE}); }
                   1734:     if (!ref($self->{FINISH_RESOURCE})) { $self->{FINISH_RESOURCE} = 
                   1735:              $self->{NAV_MAP}->getById($self->{FINISH_RESOURCE}); }
                   1736: 
                   1737:     $self->{FILTER} = shift;
                   1738: 
                   1739:     # A hash, used as a set, of resource already seen
                   1740:     $self->{ALREADY_SEEN} = shift;
                   1741:     if (!defined($self->{ALREADY_SEEN})) { $self->{ALREADY_SEEN} = {} };
1.63      bowersj2 1742:     $self->{CONDITION} = shift;
1.89      bowersj2 1743:     $self->{DIRECTION} = shift || FORWARD();
1.51      bowersj2 1744: 
1.100     bowersj2 1745:     # Flag: Have we started yet?
1.51      bowersj2 1746:     $self->{STARTED} = 0;
                   1747: 
                   1748:     # Should we continue calling the recursive iterator, if any?
                   1749:     $self->{RECURSIVE_ITERATOR_FLAG} = 0;
                   1750:     # The recursive iterator, if any
                   1751:     $self->{RECURSIVE_ITERATOR} = undef;
                   1752:     # Are we recursing on a map, or a branch?
                   1753:     $self->{RECURSIVE_MAP} = 1; # we'll manually unset this when recursing on branches
                   1754:     # And the count of how deep it is, so that this iterator can keep track of
                   1755:     # when to pick back up again.
                   1756:     $self->{RECURSIVE_DEPTH} = 0;
                   1757: 
                   1758:     # For keeping track of our branches, we maintain our own stack
1.100     bowersj2 1759:     $self->{STACK} = [];
1.51      bowersj2 1760: 
                   1761:     # Start with the first resource
1.89      bowersj2 1762:     if ($self->{DIRECTION} == FORWARD) {
1.100     bowersj2 1763:         push @{$self->{STACK}}, $self->{FIRST_RESOURCE};
1.89      bowersj2 1764:     } else {
1.100     bowersj2 1765:         push @{$self->{STACK}}, $self->{FINISH_RESOURCE};
1.89      bowersj2 1766:     }
1.51      bowersj2 1767: 
                   1768:     bless($self);
                   1769:     return $self;
                   1770: }
                   1771: 
                   1772: sub next {
                   1773:     my $self = shift;
                   1774:     
                   1775:     # Are we using a recursive iterator? If so, pull from that and
                   1776:     # watch the depth; we want to resume our level at the correct time.
1.98      bowersj2 1777:     if ($self->{RECURSIVE_ITERATOR_FLAG}) {
1.51      bowersj2 1778:         # grab the next from the recursive iterator
                   1779:         my $next = $self->{RECURSIVE_ITERATOR}->next();
                   1780:         
                   1781:         # is it a begin or end map? Update depth if so
                   1782:         if ($next == BEGIN_MAP() ) { $self->{RECURSIVE_DEPTH}++; }
                   1783:         if ($next == END_MAP() ) { $self->{RECURSIVE_DEPTH}--; }
                   1784: 
                   1785:         # Are we back at depth 0? If so, stop recursing.
                   1786:         if ($self->{RECURSIVE_DEPTH} == 0) {
                   1787:             $self->{RECURSIVE_ITERATOR_FLAG} = 0;
                   1788:         }
                   1789:         
                   1790:         return $next;
                   1791:     }
                   1792: 
                   1793:     # Is there a current resource to grab? If not, then return
1.100     bowersj2 1794:     # END_MAP, which will end the iterator.
                   1795:     if (scalar(@{$self->{STACK}}) == 0) {
                   1796:         return $self->END_MAP();
1.51      bowersj2 1797:     }
                   1798: 
                   1799:     # Have we not yet begun? If not, return BEGIN_MAP and 
                   1800:     # remember that we've started.
                   1801:     if ( !$self->{STARTED} ) {
                   1802:         $self->{STARTED} = 1;
                   1803:         return $self->BEGIN_MAP;
                   1804:     }
                   1805: 
                   1806:     # Get the next resource in the branch
1.100     bowersj2 1807:     $self->{HERE} = pop @{$self->{STACK}};
1.52      bowersj2 1808: 
1.100     bowersj2 1809:     # remember that we've seen this, so we don't return it again later
1.51      bowersj2 1810:     $self->{ALREADY_SEEN}->{$self->{HERE}->{ID}} = 1;
                   1811:     
                   1812:     # Get the next possible resources
1.90      bowersj2 1813:     my $nextUnfiltered;
1.89      bowersj2 1814:     if ($self->{DIRECTION} == FORWARD()) {
1.90      bowersj2 1815:         $nextUnfiltered = $self->{HERE}->getNext();
1.89      bowersj2 1816:     } else {
1.90      bowersj2 1817:         $nextUnfiltered = $self->{HERE}->getPrevious();
1.89      bowersj2 1818:     }
1.51      bowersj2 1819:     my $next = [];
                   1820: 
                   1821:     # filter the next possibilities to remove things we've 
1.100     bowersj2 1822:     # already seen.
1.51      bowersj2 1823:     foreach (@$nextUnfiltered) {
1.52      bowersj2 1824:         if (!defined($self->{ALREADY_SEEN}->{$_->{ID}})) {
                   1825:             push @$next, $_;
                   1826:         }
1.51      bowersj2 1827:     }
                   1828: 
                   1829:     while (@$next) {
1.100     bowersj2 1830:         # copy the next possibilities over to the stack
                   1831:         push @{$self->{STACK}}, shift @$next;
1.51      bowersj2 1832:     }
                   1833: 
                   1834:     # If this is a map and we want to recurse down it... (not filtered out)
1.70      bowersj2 1835:     if ($self->{HERE}->is_map() && 
1.63      bowersj2 1836:          (defined($self->{FILTER}->{$self->{HERE}->map_pc()}) xor $self->{CONDITION})) { 
1.51      bowersj2 1837:         $self->{RECURSIVE_ITERATOR_FLAG} = 1;
                   1838:         my $firstResource = $self->{HERE}->map_start();
                   1839:         my $finishResource = $self->{HERE}->map_finish();
                   1840: 
                   1841:         $self->{RECURSIVE_ITERATOR} =
1.94      bowersj2 1842:           Apache::lonnavmaps::DFSiterator->new ($self->{NAV_MAP}, $firstResource, 
1.63      bowersj2 1843:                      $finishResource, $self->{FILTER}, $self->{ALREADY_SEEN},
1.91      bowersj2 1844:                                              $self->{CONDITION}, $self->{DIRECTION});
1.51      bowersj2 1845:     }
                   1846: 
                   1847:     return $self->{HERE};
                   1848: }
                   1849: 
1.1       www      1850: 1;
1.2       www      1851: 
1.51      bowersj2 1852: package Apache::lonnavmaps::resource;
                   1853: 
                   1854: use Apache::lonnet;
                   1855: 
                   1856: =pod
                   1857: 
                   1858: =head1 Object: resource
                   1859: 
                   1860: A resource object encapsulates a resource in a resource map, allowing easy manipulation of the resource, querying the properties of the resource (including user properties), and represents a reference that can be used as the canonical representation of the resource by lonnavmap clients like renderers.
                   1861: 
                   1862: A resource only makes sense in the context of a navmap, as some of the data is stored in the navmap object.
                   1863: 
                   1864: You will probably never need to instantiate this object directly. Use Apache::lonnavmap::navmap, and use the "start" method to obtain the starting resource.
                   1865: 
                   1866: =head2 Public Members
                   1867: 
                   1868: resource objects have a hash called DATA ($resourceRef->{DATA}) that you can store whatever you want in. This allows you to easily do two-pass algorithms without worrying about managing your own resource->data hash.
                   1869: 
                   1870: =head2 Methods
                   1871: 
                   1872: =over 4
                   1873: 
1.70      bowersj2 1874: =item * B<new>($navmapRef, $idString): The first arg is a reference to the parent navmap object. The second is the idString of the resource itself. Very rarely, if ever, called directly. Use the nav map->getByID() method.
                   1875: 
                   1876: =back
1.51      bowersj2 1877: 
                   1878: =cut
                   1879: 
                   1880: sub new {
                   1881:     # magic invocation to create a class instance
                   1882:     my $proto = shift;
                   1883:     my $class = ref($proto) || $proto;
                   1884:     my $self = {};
                   1885: 
                   1886:     $self->{NAV_MAP} = shift;
                   1887:     $self->{ID} = shift;
                   1888: 
                   1889:     # Store this new resource in the parent nav map's cache.
                   1890:     $self->{NAV_MAP}->{RESOURCE_CACHE}->{$self->{ID}} = $self;
1.66      bowersj2 1891:     $self->{RESOURCE_ERROR} = 0;
1.51      bowersj2 1892: 
                   1893:     # A hash that can be used by two-pass algorithms to store data
                   1894:     # about this resource in. Not used by the resource object
                   1895:     # directly.
                   1896:     $self->{DATA} = {};
                   1897:    
                   1898:     bless($self);
                   1899:     
                   1900:     return $self;
                   1901: }
                   1902: 
1.70      bowersj2 1903: # private function: simplify the NAV_HASH lookups we keep doing
                   1904: # pass the name, and to automatically append my ID, pass a true val on the
                   1905: # second param
                   1906: sub navHash {
                   1907:     my $self = shift;
                   1908:     my $param = shift;
                   1909:     my $id = shift;
1.115     bowersj2 1910:     return $self->{NAV_MAP}->navhash($param . ($id?$self->{ID}:""));
1.70      bowersj2 1911: }
                   1912: 
1.51      bowersj2 1913: =pod
                   1914: 
1.70      bowersj2 1915: B<Metadata Retreival>
                   1916: 
1.101     bowersj2 1917: These are methods that help you retrieve metadata about the resource: Method names are based on the fields in the compiled course representation.
1.70      bowersj2 1918: 
                   1919: =over 4
                   1920: 
1.106     bowersj2 1921: =item * B<compTitle>: Returns a "composite title", that is equal to $res->title() if the resource has a title, and is otherwise the last part of the URL (e.g., "problem.problem").
                   1922: 
1.70      bowersj2 1923: =item * B<ext>: Returns true if the resource is external.
                   1924: 
                   1925: =item * B<goesto>: Returns the "goesto" value from the compiled nav map. (It is likely you want to use B<getNext> instead.)
                   1926: 
                   1927: =item * B<kind>: Returns the kind of the resource from the compiled nav map.
                   1928: 
1.101     bowersj2 1929: =item * B<randomout>: Returns true if this resource was chosen to NOT be shown to the user by the random map selection feature. In other words, this is usually false.
1.51      bowersj2 1930: 
1.70      bowersj2 1931: =item * B<randompick>: Returns true for a map if the randompick feature is being used on the map. (?)
                   1932: 
                   1933: =item * B<src>: Returns the source for the resource.
                   1934: 
                   1935: =item * B<symb>: Returns the symb for the resource.
                   1936: 
                   1937: =item * B<title>: Returns the title of the resource.
                   1938: 
                   1939: =item * B<to>: Returns the "to" value from the compiled nav map. (It is likely you want to use B<getNext> instead.)
1.51      bowersj2 1940: 
                   1941: =back
                   1942: 
                   1943: =cut
                   1944: 
                   1945: # These info functions can be used directly, as they don't return
                   1946: # resource information.
1.85      bowersj2 1947: sub comesfrom { my $self=shift; return $self->navHash("comesfrom_", 1); }
1.70      bowersj2 1948: sub ext { my $self=shift; return $self->navHash("ext_", 1) eq 'true:'; }
1.85      bowersj2 1949: sub from { my $self=shift; return $self->navHash("from_", 1); }
1.51      bowersj2 1950: sub goesto { my $self=shift; return $self->navHash("goesto_", 1); }
                   1951: sub kind { my $self=shift; return $self->navHash("kind_", 1); }
1.68      bowersj2 1952: sub randomout { my $self=shift; return $self->navHash("randomout_", 1); }
                   1953: sub randompick { 
                   1954:     my $self = shift;
                   1955:     return $self->{NAV_MAP}->{PARM_HASH}->{$self->symb .
                   1956:                                                '.0.parameter_randompick'};
                   1957: }
1.51      bowersj2 1958: sub src { 
                   1959:     my $self=shift;
                   1960:     return $self->navHash("src_", 1);
                   1961: }
                   1962: sub symb {
                   1963:     my $self=shift;
                   1964:     (my $first, my $second) = $self->{ID} =~ /(\d+).(\d+)/;
                   1965:     my $symbSrc = &Apache::lonnet::declutter($self->src());
                   1966:     return &Apache::lonnet::declutter(
                   1967:          $self->navHash('map_id_'.$first)) 
                   1968:         . '___' . $second . '___' . $symbSrc;
                   1969: }
1.70      bowersj2 1970: sub title { my $self=shift; return $self->navHash("title_", 1); }
                   1971: sub to { my $self=shift; return $self->navHash("to_", 1); }
1.106     bowersj2 1972: sub compTitle {
                   1973:     my $self = shift;
                   1974:     my $title = $self->title();
                   1975:     if (!$title) {
                   1976:         $title = $self->src();
                   1977:         $title = substr($title, rindex($title, '/') + 1);
                   1978:     }
                   1979:     return $title;
                   1980: }
1.70      bowersj2 1981: =pod
                   1982: 
                   1983: B<Predicate Testing the Resource>
                   1984: 
                   1985: These methods are shortcuts to deciding if a given resource has a given property.
                   1986: 
                   1987: =over 4
                   1988: 
                   1989: =item * B<is_map>: Returns true if the resource is a map type.
                   1990: 
                   1991: =item * B<is_problem>: Returns true if the resource is a problem type, false otherwise. (Looks at the extension on the src field; might need more to work correctly.)
                   1992: 
                   1993: =item * B<is_page>: Returns true if the resource is a page.
                   1994: 
                   1995: =item * B<is_problem>: Returns true if the resource is a problem.
                   1996: 
1.101     bowersj2 1997: =item * B<is_sequence>: Returns true if the resource is a sequence.
1.70      bowersj2 1998: 
                   1999: =back
                   2000: 
                   2001: =cut
                   2002: 
                   2003: 
                   2004: sub is_html {
1.51      bowersj2 2005:     my $self=shift;
                   2006:     my $src = $self->src();
1.70      bowersj2 2007:     return ($src =~ /html$/);
1.51      bowersj2 2008: }
1.70      bowersj2 2009: sub is_map { my $self=shift; return defined($self->navHash("is_map_", 1)); }
                   2010: sub is_page {
1.51      bowersj2 2011:     my $self=shift;
                   2012:     my $src = $self->src();
1.70      bowersj2 2013:     return ($src =~ /page$/);
1.51      bowersj2 2014: }
1.70      bowersj2 2015: sub is_problem {
1.51      bowersj2 2016:     my $self=shift;
                   2017:     my $src = $self->src();
1.70      bowersj2 2018:     return ($src =~ /problem$/);
1.51      bowersj2 2019: }
1.70      bowersj2 2020: sub is_sequence {
1.51      bowersj2 2021:     my $self=shift;
                   2022:     my $src = $self->src();
1.70      bowersj2 2023:     return ($src =~ /sequence$/);
1.51      bowersj2 2024: }
                   2025: 
1.101     bowersj2 2026: # Private method: Shells out to the parmval in the nav map, handler parts.
1.51      bowersj2 2027: sub parmval {
                   2028:     my $self = shift;
                   2029:     my $what = shift;
                   2030:     my $part = shift || "0";
                   2031:     return $self->{NAV_MAP}->parmval($part.'.'.$what, $self->symb());
                   2032: }
                   2033: 
1.70      bowersj2 2034: =pod
                   2035: 
                   2036: B<Map Methods>
                   2037: 
                   2038: These methods are useful for getting information about the map properties of the resource, if the resource is a map (B<is_map>).
                   2039: 
                   2040: =over 4
                   2041: 
                   2042: =item * B<map_finish>: Returns a reference to a resource object corresponding to the finish resource of the map.
                   2043: 
                   2044: =item * B<map_pc>: Returns the pc value of the map, which is the first number that appears in the resource ID of the resources in the map, and is the number that appears around the middle of the symbs of the resources in that map.
                   2045: 
                   2046: =item * B<map_start>: Returns a reference to a resource object corresponding to the start resource of the map.
                   2047: 
                   2048: =item * B<map_type>: Returns a string with the type of the map in it.
                   2049: 
                   2050: =back
1.51      bowersj2 2051: 
1.70      bowersj2 2052: =cut
1.51      bowersj2 2053: 
                   2054: sub map_finish {
                   2055:     my $self = shift;
                   2056:     my $src = $self->src();
                   2057:     my $res = $self->navHash("map_finish_$src", 0);
                   2058:     $res = $self->{NAV_MAP}->getById($res);
                   2059:     return $res;
                   2060: }
1.70      bowersj2 2061: sub map_pc {
                   2062:     my $self = shift;
                   2063:     my $src = $self->src();
                   2064:     return $self->navHash("map_pc_$src", 0);
                   2065: }
1.51      bowersj2 2066: sub map_start {
                   2067:     my $self = shift;
                   2068:     my $src = $self->src();
                   2069:     my $res = $self->navHash("map_start_$src", 0);
                   2070:     $res = $self->{NAV_MAP}->getById($res);
                   2071:     return $res;
                   2072: }
                   2073: sub map_type {
                   2074:     my $self = shift;
                   2075:     my $pc = $self->map_pc();
                   2076:     return $self->navHash("map_type_$pc", 0);
                   2077: }
                   2078: 
                   2079: 
                   2080: 
                   2081: #####
                   2082: # Property queries
                   2083: #####
                   2084: 
                   2085: # These functions will be responsible for returning the CORRECT
                   2086: # VALUE for the parameter, no matter what. So while they may look
                   2087: # like direct calls to parmval, they can be more then that.
                   2088: # So, for instance, the duedate function should use the "duedatetype"
                   2089: # information, rather then the resource object user.
                   2090: 
                   2091: =pod
                   2092: 
                   2093: =head2 Resource Parameters
                   2094: 
1.70      bowersj2 2095: In order to use the resource parameters correctly, the nav map must have been instantiated with genCourseAndUserOptions set to true, so the courseopt and useropt is read correctly. Then, you can call these functions to get the relevant parameters for the resource. Each function defaults to part "0", but can be directed to another part by passing the part as the parameter.
1.51      bowersj2 2096: 
                   2097: These methods are responsible for getting the parameter correct, not merely reflecting the contents of the GDBM hashes. As we move towards dates relative to other dates, these methods should be updated to reflect that. (Then, anybody using these methods won't have to update their code.)
                   2098: 
                   2099: =over 4
                   2100: 
                   2101: =item * B<acc>: Get the Client IP/Name Access Control information.
                   2102: 
                   2103: =item * B<answerdate>: Get the answer-reveal date for the problem.
                   2104: 
                   2105: =item * B<duedate>: Get the due date for the problem.
                   2106: 
                   2107: =item * B<tries>: Get the number of tries the student has used on the problem.
                   2108: 
                   2109: =item * B<maxtries>: Get the number of max tries allowed.
                   2110: 
                   2111: =item * B<opendate>: Get the open date for the problem.
                   2112: 
                   2113: =item * B<sig>: Get the significant figures setting.
                   2114: 
                   2115: =item * B<tol>: Get the tolerance for the problem.
                   2116: 
1.70      bowersj2 2117: =item * B<tries>: Get the number of tries the user has already used on the problem.
                   2118: 
1.51      bowersj2 2119: =item * B<type>: Get the question type for the problem.
                   2120: 
                   2121: =item * B<weight>: Get the weight for the problem.
                   2122: 
                   2123: =back
                   2124: 
                   2125: =cut
                   2126: 
                   2127: sub acc {
                   2128:     (my $self, my $part) = @_;
                   2129:     return $self->parmval("acc", $part);
                   2130: }
                   2131: sub answerdate {
                   2132:     (my $self, my $part) = @_;
                   2133:     # Handle intervals
                   2134:     if ($self->parmval("answerdate.type", $part) eq 'date_interval') {
                   2135:         return $self->duedate($part) + 
                   2136:             $self->parmval("answerdate", $part);
                   2137:     }
                   2138:     return $self->parmval("answerdate", $part);
1.106     bowersj2 2139: }
1.108     bowersj2 2140: sub awarded { my $self = shift; return $self->queryRestoreHash('awarded', shift); }
1.51      bowersj2 2141: sub duedate {
                   2142:     (my $self, my $part) = @_;
                   2143:     return $self->parmval("duedate", $part);
                   2144: }
                   2145: sub maxtries {
                   2146:     (my $self, my $part) = @_;
                   2147:     return $self->parmval("maxtries", $part);
                   2148: }
                   2149: sub opendate {
                   2150:     (my $self, my $part) = @_;
                   2151:     if ($self->parmval("opendate.type", $part) eq 'date_interval') {
                   2152:         return $self->duedate($part) -
                   2153:             $self->parmval("opendate", $part);
                   2154:     }
                   2155:     return $self->parmval("opendate");
                   2156: }
                   2157: sub sig {
                   2158:     (my $self, my $part) = @_;
                   2159:     return $self->parmval("sig", $part);
                   2160: }
                   2161: sub tol {
                   2162:     (my $self, my $part) = @_;
                   2163:     return $self->parmval("tol", $part);
                   2164: }
1.108     bowersj2 2165: sub tries { 
                   2166:     my $self = shift; 
                   2167:     my $tries = $self->queryRestoreHash('tries', shift);
                   2168:     if (!defined($tries)) { return '0';}
1.51      bowersj2 2169:     return $tries;
                   2170: }
1.70      bowersj2 2171: sub type {
                   2172:     (my $self, my $part) = @_;
                   2173:     return $self->parmval("type", $part);
                   2174: }
1.109     bowersj2 2175: sub weight { 
                   2176:     my $self = shift; my $part = shift;
1.70      bowersj2 2177:     return $self->parmval("weight", $part);
                   2178: }
1.51      bowersj2 2179: 
                   2180: # Multiple things need this
                   2181: sub getReturnHash {
                   2182:     my $self = shift;
                   2183:     
                   2184:     if (!defined($self->{RETURN_HASH})) {
1.84      bowersj2 2185:         my %tmpHash  = &Apache::lonnet::restore($self->symb());
1.51      bowersj2 2186:         $self->{RETURN_HASH} = \%tmpHash;
                   2187:     }
                   2188: }       
                   2189: 
                   2190: ######
                   2191: # Status queries
                   2192: ######
                   2193: 
                   2194: # These methods query the status of problems.
                   2195: 
                   2196: # If we need to count parts, this function determines the number of
                   2197: # parts from the metadata. When called, it returns a reference to a list
                   2198: # of strings corresponding to the parts. (Thus, using it in a scalar context
                   2199: # tells you how many parts you have in the problem:
                   2200: # $partcount = scalar($resource->countParts());
                   2201: # Don't use $self->{PARTS} directly because you don't know if it's been
                   2202: # computed yet.
                   2203: 
                   2204: =pod
                   2205: 
                   2206: =head2 Resource misc
                   2207: 
                   2208: Misc. functions for the resource.
                   2209: 
                   2210: =over 4
                   2211: 
1.59      bowersj2 2212: =item * B<hasDiscussion>: Returns a false value if there has been discussion since the user last logged in, true if there has. Always returns false if the discussion data was not extracted when the nav map was constructed.
                   2213: 
                   2214: =item * B<getFeedback>: Gets the feedback for the resource and returns the raw feedback string for the resource, or the null string if there is no feedback or the email data was not extracted when the nav map was constructed. Usually used like this:
                   2215: 
                   2216:  for (split(/\,/, $res->getFeedback())) {
                   2217:     my $link = &Apache::lonnet::escape($_);
                   2218:     ...
                   2219: 
                   2220: and use the link as appropriate.
                   2221: 
                   2222: =cut
                   2223: 
                   2224: sub hasDiscussion {
                   2225:     my $self = shift;
                   2226:     return $self->{NAV_MAP}->hasDiscussion($self->symb());
                   2227: }
                   2228: 
                   2229: sub getFeedback {
                   2230:     my $self = shift;
1.85      bowersj2 2231:     return $self->{NAV_MAP}->getFeedback($self->src());
1.59      bowersj2 2232: }
                   2233: 
                   2234: =pod
                   2235: 
1.70      bowersj2 2236: =item * B<parts>(): Returns a list reference containing sorted strings corresponding to each part of the problem. To count the number of parts, use the list in a scalar context, and subtract one if greater then two. (One part problems have a part 0. Multi-parts have a part 0, plus a part for each part. Filtering part 0 if you want it is up to you.)
1.51      bowersj2 2237: 
1.70      bowersj2 2238: =item * B<countParts>(): Returns the number of parts of the problem a student can answer. Thus, for single part problems, returns 1. For multipart, it returns the number of parts in the problem, not including psuedo-part 0. Thus, B<parts> may return an array with fewer parts in it then countParts might lead you to believe.
1.51      bowersj2 2239: 
                   2240: =back
                   2241: 
                   2242: =cut
                   2243: 
                   2244: sub parts {
                   2245:     my $self = shift;
                   2246: 
1.67      bowersj2 2247:     if ($self->ext) { return ['0']; }
                   2248: 
1.51      bowersj2 2249:     $self->extractParts();
                   2250:     return $self->{PARTS};
                   2251: }
                   2252: 
                   2253: sub countParts {
                   2254:     my $self = shift;
                   2255:     
                   2256:     my $parts = $self->parts();
1.66      bowersj2 2257: 
                   2258:     if ($self->{RESOURCE_ERROR}) {
                   2259:         return 0;
                   2260:     }
                   2261: 
                   2262:     if (scalar(@{$parts}) < 2) { return 1;}
1.51      bowersj2 2263: 
                   2264:     return scalar(@{$parts}) - 1;
                   2265: }
                   2266: 
                   2267: # Private function: Extracts the parts information and saves it
                   2268: sub extractParts { 
                   2269:     my $self = shift;
                   2270:     
                   2271:     return if ($self->{PARTS});
1.67      bowersj2 2272:     return if ($self->ext);
1.51      bowersj2 2273: 
                   2274:     $self->{PARTS} = [];
                   2275: 
1.82      bowersj2 2276:     # Retrieve part count, if this is a problem
                   2277:     if ($self->is_problem()) {
                   2278:         my $metadata = &Apache::lonnet::metadata($self->src(), 'allpossiblekeys');
                   2279:         if (!$metadata) {
                   2280:             $self->{RESOURCE_ERROR} = 1;
                   2281:             $self->{PARTS} = [];
                   2282:             return;
                   2283:         }
                   2284:         
                   2285:         foreach (split(/\,/,$metadata)) {
                   2286:             if ($_ =~ /^parameter\_(.*)\_opendate$/) {
                   2287:                 push @{$self->{PARTS}}, $1;
                   2288:             }
1.51      bowersj2 2289:         }
1.82      bowersj2 2290:         
                   2291:         
                   2292:         # Is this possible to do in one line? - Jeremy
                   2293:         my @sortedParts = sort @{$self->{PARTS}};
                   2294:         $self->{PARTS} = \@sortedParts;
1.51      bowersj2 2295:     }
                   2296: 
                   2297:     return;
                   2298: }
                   2299: 
                   2300: =pod
                   2301: 
                   2302: =head2 Resource Status
                   2303: 
1.101     bowersj2 2304: Problem resources have status information, reflecting their various dates and completion statuses. 
1.51      bowersj2 2305: 
                   2306: There are two aspects to the status: the date-related information and the completion information.
                   2307: 
                   2308: Idiomatic usage of these two methods would probably look something like
                   2309: 
                   2310:  foreach ($resource->parts()) {
                   2311:     my $dateStatus = $resource->getDateStatus($_);
                   2312:     my $completionStatus = $resource->getCompletionStatus($_);
                   2313: 
1.70      bowersj2 2314:     or
                   2315: 
                   2316:     my $status = $resource->status($_);
                   2317: 
1.51      bowersj2 2318:     ... use it here ...
                   2319:  }
                   2320: 
1.101     bowersj2 2321: Which you use depends on exactly what you are looking for. The status() function has been optimized for the nav maps display and may not precisely match what you need elsewhere.
                   2322: 
                   2323: The symbolic constants shown below can be accessed through the resource object: $res->OPEN.
                   2324: 
1.51      bowersj2 2325: =over 4
                   2326: 
1.70      bowersj2 2327: =item * B<getDateStatus>($part): ($part defaults to 0). A convenience function that returns a symbolic constant telling you about the date status of the part. The possible return values are:
1.51      bowersj2 2328: 
                   2329: =back
                   2330: 
                   2331: B<Date Codes>
                   2332: 
                   2333: =over 4
                   2334: 
                   2335: =item * B<OPEN_LATER>: The problem will be opened later.
                   2336: 
                   2337: =item * B<OPEN>: Open and not yet due.
                   2338: 
1.59      bowersj2 2339: 
1.54      bowersj2 2340: =item * B<PAST_DUE_ANSWER_LATER>: The due date has passed, but the answer date has not yet arrived.
                   2341: 
                   2342: =item * B<PAST_DUE_NO_ANSWER>: The due date has passed and there is no answer opening date set.
1.51      bowersj2 2343: 
                   2344: =item * B<ANSWER_OPEN>: The answer date is here.
                   2345: 
                   2346: =item * B<NETWORK_FAILURE>: The information is unknown due to network failure.
                   2347: 
                   2348: =back
                   2349: 
                   2350: =cut
                   2351: 
                   2352: # Apparently the compiler optimizes these into constants automatically
1.54      bowersj2 2353: sub OPEN_LATER             { return 0; }
                   2354: sub OPEN                   { return 1; }
                   2355: sub PAST_DUE_NO_ANSWER     { return 2; }
                   2356: sub PAST_DUE_ANSWER_LATER  { return 3; }
                   2357: sub ANSWER_OPEN            { return 4; }
                   2358: sub NOTHING_SET            { return 5; } 
                   2359: sub NETWORK_FAILURE        { return 100; }
                   2360: 
                   2361: # getDateStatus gets the date status for a given problem part. 
                   2362: # Because answer date, due date, and open date are fully independent
                   2363: # (i.e., it is perfectly possible to *only* have an answer date), 
                   2364: # we have to completely cover the 3x3 maxtrix of (answer, due, open) x
                   2365: # (past, future, none given). This function handles this with a decision
                   2366: # tree. Read the comments to follow the decision tree.
1.51      bowersj2 2367: 
                   2368: sub getDateStatus {
                   2369:     my $self = shift;
                   2370:     my $part = shift;
                   2371:     $part = "0" if (!defined($part));
1.54      bowersj2 2372: 
                   2373:     # Always return network failure if there was one.
1.51      bowersj2 2374:     return $self->NETWORK_FAILURE if ($self->{NAV_MAP}->{NETWORK_FAILURE});
                   2375: 
                   2376:     my $now = time();
                   2377: 
1.53      bowersj2 2378:     my $open = $self->opendate($part);
                   2379:     my $due = $self->duedate($part);
                   2380:     my $answer = $self->answerdate($part);
                   2381: 
                   2382:     if (!$open && !$due && !$answer) {
                   2383:         # no data on the problem at all
                   2384:         # should this be the same as "open later"? think multipart.
                   2385:         return $self->NOTHING_SET;
                   2386:     }
1.59      bowersj2 2387:     if (!$open || $now < $open) {return $self->OPEN_LATER}
                   2388:     if (!$due || $now < $due) {return $self->OPEN}
                   2389:     if ($answer && $now < $answer) {return $self->PAST_DUE_ANSWER_LATER}
                   2390:     if ($answer) { return $self->ANSWER_OPEN; }
1.54      bowersj2 2391:     return PAST_DUE_NO_ANSWER;
1.51      bowersj2 2392: }
                   2393: 
                   2394: =pod
                   2395: 
                   2396: B<>
                   2397: 
                   2398: =over 4
                   2399: 
                   2400: =item * B<getCompletionStatus>($part): ($part defaults to 0.) A convenience function that returns a symbolic constant telling you about the completion status of the part, with the following possible results:
                   2401: 
                   2402: =back 
                   2403: 
                   2404: B<Completion Codes>
                   2405: 
                   2406: =over 4
                   2407: 
                   2408: =item * B<NOT_ATTEMPTED>: Has not been attempted at all.
                   2409: 
                   2410: =item * B<INCORRECT>: Attempted, but wrong by student.
                   2411: 
                   2412: =item * B<INCORRECT_BY_OVERRIDE>: Attempted, but wrong by instructor override.
                   2413: 
                   2414: =item * B<CORRECT>: Correct or correct by instructor.
                   2415: 
                   2416: =item * B<CORRECT_BY_OVERRIDE>: Correct by instructor override.
                   2417: 
                   2418: =item * B<EXCUSED>: Excused. Not yet implemented.
                   2419: 
                   2420: =item * B<NETWORK_FAILURE>: Information not available due to network failure.
                   2421: 
1.69      bowersj2 2422: =item * B<ATTEMPTED>: Attempted, and not yet graded.
                   2423: 
1.51      bowersj2 2424: =back
                   2425: 
                   2426: =cut
                   2427: 
1.53      bowersj2 2428: sub NOT_ATTEMPTED         { return 10; }
                   2429: sub INCORRECT             { return 11; }
                   2430: sub INCORRECT_BY_OVERRIDE { return 12; }
                   2431: sub CORRECT               { return 13; }
                   2432: sub CORRECT_BY_OVERRIDE   { return 14; }
                   2433: sub EXCUSED               { return 15; }
1.69      bowersj2 2434: sub ATTEMPTED             { return 16; }
1.51      bowersj2 2435: 
                   2436: sub getCompletionStatus {
                   2437:     my $self = shift;
                   2438:     return $self->NETWORK_FAILURE if ($self->{NAV_MAP}->{NETWORK_FAILURE});
                   2439: 
1.108     bowersj2 2440:     my $status = $self->queryRestoreHash('solved', shift);
1.51      bowersj2 2441: 
                   2442:     # Left as seperate if statements in case we ever do more with this
                   2443:     if ($status eq 'correct_by_student') {return $self->CORRECT;}
                   2444:     if ($status eq 'correct_by_override') {return $self->CORRECT_BY_OVERRIDE; }
                   2445:     if ($status eq 'incorrect_attempted') {return $self->INCORRECT; }
                   2446:     if ($status eq 'incorrect_by_override') {return $self->INCORRECT_BY_OVERRIDE; }
                   2447:     if ($status eq 'excused') {return $self->EXCUSED; }
1.69      bowersj2 2448:     if ($status eq 'ungraded_attempted') {return $self->ATTEMPTED; }
1.51      bowersj2 2449:     return $self->NOT_ATTEMPTED;
1.108     bowersj2 2450: }
                   2451: 
                   2452: sub queryRestoreHash {
                   2453:     my $self = shift;
                   2454:     my $hashentry = shift;
                   2455:     my $part = shift;
                   2456:     $part = "0" if (!defined($part));
                   2457:     return $self->NETWORK_FAILURE if ($self->{NAV_MAP}->{NETWORK_FAILURE});
                   2458: 
                   2459:     $self->getReturnHash();
                   2460: 
                   2461:     return $self->{RETURN_HASH}->{'resource.'.$part.'.'.$hashentry};
1.51      bowersj2 2462: }
                   2463: 
                   2464: =pod
                   2465: 
                   2466: B<Composite Status>
                   2467: 
1.101     bowersj2 2468: Along with directly returning the date or completion status, the resource object includes a convenience function B<status>() that will combine the two status tidbits into one composite status that can represent the status of the resource as a whole. The precise logic is documented in the comments of the status method. The following results may be returned, all available as methods on the resource object ($res->NETWORK_FAILURE):
1.51      bowersj2 2469: 
                   2470: =over 4
                   2471: 
1.70      bowersj2 2472: =item * B<NETWORK_FAILURE>: The network has failed and the information is not available.
1.51      bowersj2 2473: 
1.70      bowersj2 2474: =item * B<NOTHING_SET>: No dates have been set for this problem (part) at all. (Because only certain parts of a multi-part problem may be assigned, this can not be collapsed into "open later", as we don't know a given part will EVER be opened. For single part, this is the same as "OPEN_LATER".)
1.53      bowersj2 2475: 
1.70      bowersj2 2476: =item * B<CORRECT>: For any reason at all, the part is considered correct.
1.51      bowersj2 2477: 
1.70      bowersj2 2478: =item * B<EXCUSED>: For any reason at all, the problem is excused.
1.51      bowersj2 2479: 
1.70      bowersj2 2480: =item * B<PAST_DUE_NO_ANSWER>: The problem is past due, not considered correct, and no answer date is set.
1.54      bowersj2 2481: 
1.70      bowersj2 2482: =item * B<PAST_DUE_ANSWER_LATER>: The problem is past due, not considered correct, and an answer date in the future is set.
1.51      bowersj2 2483: 
1.70      bowersj2 2484: =item * B<ANSWER_OPEN>: The problem is past due, not correct, and the answer is now available.
1.51      bowersj2 2485: 
1.70      bowersj2 2486: =item * B<OPEN_LATER>: The problem is not yet open.
1.51      bowersj2 2487: 
1.70      bowersj2 2488: =item * B<TRIES_LEFT>: The problem is open, has been tried, is not correct, but there are tries left.
1.51      bowersj2 2489: 
1.70      bowersj2 2490: =item * B<INCORRECT>: The problem is open, and all tries have been used without getting the correct answer.
1.51      bowersj2 2491: 
1.70      bowersj2 2492: =item * B<OPEN>: The item is open and not yet tried.
1.51      bowersj2 2493: 
1.70      bowersj2 2494: =item * B<ATTEMPTED>: The problem has been attempted.
1.69      bowersj2 2495: 
1.51      bowersj2 2496: =back
                   2497: 
                   2498: =cut
                   2499: 
                   2500: sub TRIES_LEFT { return 10; }
                   2501: 
                   2502: sub status {
                   2503:     my $self = shift;
                   2504:     my $part = shift;
                   2505:     if (!defined($part)) { $part = "0"; }
                   2506:     my $completionStatus = $self->getCompletionStatus($part);
                   2507:     my $dateStatus = $self->getDateStatus($part);
                   2508: 
                   2509:     # What we have is a two-dimensional matrix with 4 entries on one
                   2510:     # dimension and 5 entries on the other, which we want to colorize,
1.54      bowersj2 2511:     # plus network failure and "no date data at all".
1.51      bowersj2 2512: 
1.53      bowersj2 2513:     if ($completionStatus == NETWORK_FAILURE) { return NETWORK_FAILURE; }
1.51      bowersj2 2514: 
                   2515:     # There are a few whole rows we can dispose of:
1.53      bowersj2 2516:     if ($completionStatus == CORRECT ||
                   2517:         $completionStatus == CORRECT_BY_OVERRIDE ) {
1.69      bowersj2 2518:         return CORRECT; 
                   2519:     }
                   2520: 
                   2521:     if ($completionStatus == ATTEMPTED) {
                   2522:         return ATTEMPTED;
1.53      bowersj2 2523:     }
                   2524: 
                   2525:     # If it's EXCUSED, then return that no matter what
                   2526:     if ($completionStatus == EXCUSED) {
                   2527:         return EXCUSED; 
1.51      bowersj2 2528:     }
                   2529: 
1.53      bowersj2 2530:     if ($dateStatus == NOTHING_SET) {
                   2531:         return NOTHING_SET;
1.51      bowersj2 2532:     }
                   2533: 
1.69      bowersj2 2534:     # Now we're down to a 4 (incorrect, incorrect_override, not_attempted)
                   2535:     # by 4 matrix (date statuses).
1.51      bowersj2 2536: 
1.54      bowersj2 2537:     if ($dateStatus == PAST_DUE_ANSWER_LATER ||
1.59      bowersj2 2538:         $dateStatus == PAST_DUE_NO_ANSWER ) {
1.54      bowersj2 2539:         return $dateStatus; 
1.51      bowersj2 2540:     }
                   2541: 
1.53      bowersj2 2542:     if ($dateStatus == ANSWER_OPEN) {
                   2543:         return ANSWER_OPEN;
1.51      bowersj2 2544:     }
                   2545: 
                   2546:     # Now: (incorrect, incorrect_override, not_attempted) x 
                   2547:     # (open_later), (open)
                   2548:     
1.53      bowersj2 2549:     if ($dateStatus == OPEN_LATER) {
                   2550:         return OPEN_LATER;
1.51      bowersj2 2551:     }
                   2552: 
                   2553:     # If it's WRONG...
1.53      bowersj2 2554:     if ($completionStatus == INCORRECT || $completionStatus == INCORRECT_BY_OVERRIDE) {
1.51      bowersj2 2555:         # and there are TRIES LEFT:
1.79      bowersj2 2556:         if ($self->tries($part) < $self->maxtries($part) || !$self->maxtries($part)) {
1.53      bowersj2 2557:             return TRIES_LEFT;
1.51      bowersj2 2558:         }
1.53      bowersj2 2559:         return INCORRECT; # otherwise, return orange; student can't fix this
1.51      bowersj2 2560:     }
                   2561: 
                   2562:     # Otherwise, it's untried and open
1.53      bowersj2 2563:     return OPEN; 
1.51      bowersj2 2564: }
                   2565: 
                   2566: =pod
                   2567: 
                   2568: =head2 Resource/Nav Map Navigation
                   2569: 
                   2570: =over 4
                   2571: 
1.101     bowersj2 2572: =item * B<getNext>(): Retreive an array of the possible next resources after this one. Always returns an array, even in the one- or zero-element case. 
1.85      bowersj2 2573: 
1.101     bowersj2 2574: =item * B<getPrevious>(): Retreive an array of the possible previous resources from this one. Always returns an array, even in the one- or zero-element case. 
1.51      bowersj2 2575: 
                   2576: =cut
                   2577: 
                   2578: sub getNext {
                   2579:     my $self = shift;
                   2580:     my @branches;
                   2581:     my $to = $self->to();
1.85      bowersj2 2582:     foreach my $branch ( split(/,/, $to) ) {
1.51      bowersj2 2583:         my $choice = $self->{NAV_MAP}->getById($branch);
                   2584:         my $next = $choice->goesto();
                   2585:         $next = $self->{NAV_MAP}->getById($next);
                   2586: 
1.101     bowersj2 2587:         # Don't remember it if the student doesn't have browse priviledges
                   2588:         # future note: this may properly belong in the client of the resource
1.114     bowersj2 2589:         my $browsePriv = $self->{BROWSE_PRIV};
                   2590:         if (!defined($browsePriv)) {
                   2591:             $browsePriv = &Apache::lonnet::allowed('bre', $self->src);
                   2592:             $self->{BROWSE_PRIV} = $browsePriv;
                   2593:         }
1.102     bowersj2 2594:         if (!($browsePriv ne '2' && $browsePriv ne 'F')) {
1.101     bowersj2 2595:             push @branches, $next;
                   2596:         }
1.85      bowersj2 2597:     }
                   2598:     return \@branches;
                   2599: }
                   2600: 
                   2601: sub getPrevious {
                   2602:     my $self = shift;
                   2603:     my @branches;
                   2604:     my $from = $self->from();
                   2605:     foreach my $branch ( split /,/, $from) {
                   2606:         my $choice = $self->{NAV_MAP}->getById($branch);
                   2607:         my $prev = $choice->comesfrom();
                   2608:         $prev = $self->{NAV_MAP}->getById($prev);
                   2609: 
1.101     bowersj2 2610:         # Don't remember it if the student doesn't have browse priviledges
                   2611:         # future note: this may properly belong in the client of the resource
1.114     bowersj2 2612:         my $browsePriv = $self->{BROWSE_PRIV};
                   2613:         if (!defined($browsePriv)) {
                   2614:             $browsePriv = &Apache::lonnet::allowed('bre', $self->src);
                   2615:             $self->{BROWSE_PRIV} = $browsePriv;
                   2616:         }
1.103     bowersj2 2617:         if (!($browsePriv ne '2' && $browsePriv ne 'F')) {
1.87      www      2618:             push @branches, $prev;
1.85      bowersj2 2619:         }
1.51      bowersj2 2620:     }
                   2621:     return \@branches;
                   2622: }
                   2623: 
                   2624: =pod
1.2       www      2625: 
1.51      bowersj2 2626: =back
1.2       www      2627: 
1.51      bowersj2 2628: =cut
1.2       www      2629: 
1.51      bowersj2 2630: 1;
1.2       www      2631: 
1.51      bowersj2 2632: __END__
1.2       www      2633: 
                   2634: 

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