Annotation of loncom/interface/lonhelper.pm, revision 1.26

1.1       bowersj2    1: # The LearningOnline Network with CAPA
                      2: # .helper XML handler to implement the LON-CAPA helper
                      3: #
1.26    ! bowersj2    4: # $Id: lonhelper.pm,v 1.25 2003/05/08 19:52:43 bowersj2 Exp $
1.1       bowersj2    5: #
                      6: # Copyright Michigan State University Board of Trustees
                      7: #
                      8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
                      9: #
                     10: # LON-CAPA is free software; you can redistribute it and/or modify
                     11: # it under the terms of the GNU General Public License as published by
                     12: # the Free Software Foundation; either version 2 of the License, or
                     13: # (at your option) any later version.
                     14: #
                     15: # LON-CAPA is distributed in the hope that it will be useful,
                     16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
                     17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
                     18: # GNU General Public License for more details.
                     19: #
                     20: # You should have received a copy of the GNU General Public License
                     21: # along with LON-CAPA; if not, write to the Free Software
                     22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
                     23: #
                     24: # /home/httpd/html/adm/gpl.txt
                     25: #
                     26: # http://www.lon-capa.org/
                     27: #
                     28: # (Page Handler
                     29: #
                     30: # (.helper handler
                     31: #
                     32: 
1.3       bowersj2   33: =pod
                     34: 
                     35: =head1 lonhelper - HTML Helper framework for LON-CAPA
                     36: 
                     37: Helpers, often known as "wizards", are well-established UI widgets that users
                     38: feel comfortable with. It can take a complicated multidimensional problem the
                     39: user has and turn it into a series of bite-sized one-dimensional questions.
                     40: 
                     41: For developers, helpers provide an easy way to bundle little bits of functionality
                     42: for the user, without having to write the tedious state-maintenence code.
                     43: 
                     44: Helpers are defined as XML documents, placed in the /home/httpd/html/adm/helpers 
                     45: directory and having the .helper file extension. For examples, see that directory.
                     46: 
                     47: All classes are in the Apache::lonhelper namespace.
                     48: 
                     49: =head2 lonhelper XML file format
                     50: 
                     51: A helper consists of a top-level <helper> tag which contains a series of states.
                     52: Each state contains one or more state elements, which are what the user sees, like
                     53: messages, resource selections, or date queries.
                     54: 
                     55: The helper tag is required to have one attribute, "title", which is the name
                     56: of the helper itself, such as "Parameter helper". 
                     57: 
                     58: =head2 State tags
                     59: 
                     60: State tags are required to have an attribute "name", which is the symbolic
1.7       bowersj2   61: name of the state and will not be directly seen by the user. The helper is
                     62: required to have one state named "START", which is the state the helper
1.5       bowersj2   63: will start with. By convention, this state should clearly describe what
1.3       bowersj2   64: the helper will do for the user, and may also include the first information
                     65: entry the user needs to do for the helper.
                     66: 
                     67: State tags are also required to have an attribute "title", which is the
                     68: human name of the state, and will be displayed as the header on top of 
                     69: the screen for the user.
                     70: 
                     71: =head2 Example Helper Skeleton
                     72: 
                     73: An example of the tags so far:
                     74: 
                     75:  <helper title="Example Helper">
                     76:    <state name="START" title="Demonstrating the Example Helper">
                     77:      <!-- notice this is the START state the wizard requires -->
                     78:      </state>
                     79:    <state name="GET_NAME" title="Enter Student Name">
                     80:      </state>
                     81:    </helper>
                     82: 
                     83: Of course this does nothing. In order for the wizard to do something, it is
                     84: necessary to put actual elements into the wizard. Documentation for each
                     85: of these elements follows.
                     86: 
1.13      bowersj2   87: =head2 Creating a Helper With Code, Not XML
                     88: 
                     89: In some situations, such as the printing wizard (see lonprintout.pm), 
                     90: writing the helper in XML would be too complicated, because of scope 
                     91: issues or the fact that the code actually outweighs the XML. It is
                     92: possible to create a helper via code, though it is a little odd.
                     93: 
                     94: Creating a helper via code is more like issuing commands to create
                     95: a helper then normal code writing. For instance, elements will automatically
                     96: be added to the last state created, so it's important to create the 
                     97: states in the correct order.
                     98: 
                     99: First, create a new helper:
                    100: 
                    101:  use Apache::lonhelper;
                    102: 
                    103:  my $helper = Apache::lonhelper::new->("Helper Title");
                    104: 
                    105: Next you'll need to manually add states to the helper:
                    106: 
                    107:  Apache::lonhelper::state->new("STATE_NAME", "State's Human Title");
                    108: 
                    109: You don't need to save a reference to it because all elements up until
                    110: the next state creation will automatically be added to this state.
                    111: 
                    112: Elements are created by populating the $paramHash in 
                    113: Apache::lonhelper::paramhash. To prevent namespace issues, retrieve 
                    114: a reference to that has with getParamHash:
                    115: 
                    116:  my $paramHash = Apache::lonhelper::getParamHash();
                    117: 
                    118: You will need to do this for each state you create.
                    119: 
                    120: Populate the $paramHash with the parameters for the element you wish
                    121: to add next; the easiest way to find out what those entries are is
                    122: to read the code. Some common ones are 'variable' to record the variable
                    123: to store the results in, and NEXTSTATE to record a next state transition.
                    124: 
                    125: Then create your element:
                    126: 
                    127:  $paramHash->{MESSAGETEXT} = "This is a message.";
                    128:  Apache::lonhelper::message->new();
                    129: 
                    130: The creation will take the $paramHash and bless it into a
                    131: Apache::lonhelper::message object. To create the next element, you need
                    132: to get a reference to the new, empty $paramHash:
                    133: 
                    134:  $paramHash = Apache::lonhelper::getParamHash();
                    135: 
                    136: and you can repeat creating elements that way. You can add states
                    137: and elements as needed.
                    138: 
                    139: See lonprintout.pm, subroutine printHelper for an example of this, where
                    140: we dynamically add some states to prevent security problems, for instance.
                    141: 
                    142: Normally the machinery in the XML format is sufficient; dynamically 
                    143: adding states can easily be done by wrapping the state in a <condition>
                    144: tag. This should only be used when the code dominates the XML content,
                    145: the code is so complicated that it is difficult to get access to
                    146: all of the information you need because of scoping issues, or so much
                    147: of the information used is persistent because would-be <exec> or 
                    148: <eval> blocks that using the {DATA} mechanism results in hard-to-read
                    149: and -maintain code.
                    150: 
                    151: It is possible to do some of the work with an XML fragment parsed by
1.17      bowersj2  152: lonxml; again, see lonprintout.pm for an example. In that case it is 
                    153: imperative that you call B<Apache::lonhelper::registerHelperTags()>
                    154: before parsing XML fragments and B<Apache::lonhelper::unregisterHelperTags()>
                    155: when you are done. See lonprintout.pm for examples of this usage in the
                    156: printHelper subroutine.
1.13      bowersj2  157: 
1.3       bowersj2  158: =cut
                    159: 
1.1       bowersj2  160: package Apache::lonhelper;
1.2       bowersj2  161: use Apache::Constants qw(:common);
                    162: use Apache::File;
1.3       bowersj2  163: use Apache::lonxml;
1.2       bowersj2  164: 
1.7       bowersj2  165: # Register all the tags with the helper, so the helper can 
                    166: # push and pop them
                    167: 
                    168: my @helperTags;
                    169: 
                    170: sub register {
                    171:     my ($namespace, @tags) = @_;
                    172: 
                    173:     for my $tag (@tags) {
                    174:         push @helperTags, [$namespace, $tag];
                    175:     }
                    176: }
                    177: 
1.2       bowersj2  178: BEGIN {
1.7       bowersj2  179:     Apache::lonxml::register('Apache::lonhelper', 
                    180:                              ('helper'));
                    181:       register('Apache::lonhelper', ('state'));
1.2       bowersj2  182: }
                    183: 
1.7       bowersj2  184: # Since all helpers are only three levels deep (helper tag, state tag, 
1.3       bowersj2  185: # substate type), it's easier and more readble to explicitly track 
                    186: # those three things directly, rather then futz with the tag stack 
                    187: # every time.
                    188: my $helper;
                    189: my $state;
                    190: my $substate;
1.4       bowersj2  191: # To collect parameters, the contents of the subtags are collected
                    192: # into this paramHash, then passed to the element object when the 
                    193: # end of the element tag is located.
                    194: my $paramHash; 
1.2       bowersj2  195: 
1.25      bowersj2  196: # Note from Jeremy 5-8-2003: It is *vital* that the real handler be called
                    197: # as a subroutine from the handler, or very mysterious things might happen.
                    198: # I don't know exactly why, but it seems that the scope where the Apache
                    199: # server enters the perl handler is treated differently from the rest of
                    200: # the handler. This also seems to manifest itself in the debugger as entering
                    201: # the perl handler in seemingly random places (sometimes it starts in the
                    202: # compiling phase, sometimes in the handler execution phase where it runs
                    203: # the code and stepping into the "1;" the module ends with goes into the handler,
                    204: # sometimes starting directly with the handler); I think the cause is related.
                    205: # In the debugger, this means that breakpoints are ignored until you step into
                    206: # a function and get out of what must be a "faked up scope" in the Apache->
                    207: # mod_perl connection. In this code, it was manifesting itself in the existence
                    208: # of two seperate file-scoped $helper variables, one set to the value of the
                    209: # helper in the helper constructor, and one referenced by the handler on the
                    210: # "$helper->process()" line. The second was therefore never set, and was still
                    211: # undefined when I tried to call process on it.
                    212: # By pushing the "real handler" down into the "real scope", everybody except the 
                    213: # actual handler function directly below this comment gets the same $helper and
                    214: # everybody is happy.
                    215: # The upshot of all of this is that for safety when a handler is  using 
                    216: # file-scoped variables in LON-CAPA, the handler should be pushed down one 
                    217: # call level, as I do here, to ensure that the top-level handler function does
                    218: # not get a different file scope from the rest of the code.
                    219: sub handler {
                    220:     my $r = shift;
                    221:     return real_handler($r);
                    222: }
                    223: 
1.13      bowersj2  224: # For debugging purposes, one can send a second parameter into this
                    225: # function, the 'uri' of the helper you wish to have rendered, and
                    226: # call this from other handlers.
1.25      bowersj2  227: sub real_handler {
1.3       bowersj2  228:     my $r = shift;
1.13      bowersj2  229:     my $uri = shift;
                    230:     if (!defined($uri)) { $uri = $r->uri(); }
                    231:     $ENV{'request.uri'} = $uri;
                    232:     my $filename = '/home/httpd/html' . $uri;
1.2       bowersj2  233:     my $fh = Apache::File->new($filename);
                    234:     my $file;
1.3       bowersj2  235:     read $fh, $file, 100000000;
                    236: 
                    237:     # Send header, don't cache this page
                    238:     if ($r->header_only) {
                    239:         if ($ENV{'browser.mathml'}) {
                    240:             $r->content_type('text/xml');
                    241:         } else {
                    242:             $r->content_type('text/html');
                    243:         }
                    244:         $r->send_http_header;
                    245:         return OK;
                    246:     }
                    247:     if ($ENV{'browser.mathml'}) {
                    248:         $r->content_type('text/xml');
                    249:     } else {
                    250:         $r->content_type('text/html');
                    251:     }
                    252:     $r->send_http_header;
                    253:     $r->rflush();
1.2       bowersj2  254: 
1.3       bowersj2  255:     # Discard result, we just want the objects that get created by the
                    256:     # xml parsing
                    257:     &Apache::lonxml::xmlparse($r, 'helper', $file);
1.2       bowersj2  258: 
1.13      bowersj2  259:     $helper->process();
                    260: 
1.3       bowersj2  261:     $r->print($helper->display());
1.7       bowersj2  262:    return OK;
1.2       bowersj2  263: }
                    264: 
1.13      bowersj2  265: sub registerHelperTags {
                    266:     for my $tagList (@helperTags) {
                    267:         Apache::lonxml::register($tagList->[0], $tagList->[1]);
                    268:     }
                    269: }
                    270: 
                    271: sub unregisterHelperTags {
                    272:     for my $tagList (@helperTags) {
                    273:         Apache::lonxml::deregister($tagList->[0], $tagList->[1]);
                    274:     }
                    275: }
                    276: 
1.2       bowersj2  277: sub start_helper {
                    278:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                    279: 
                    280:     if ($target ne 'helper') {
                    281:         return '';
                    282:     }
1.7       bowersj2  283: 
1.13      bowersj2  284:     registerHelperTags();
                    285: 
                    286:     Apache::lonhelper::helper->new($token->[2]{'title'});
1.4       bowersj2  287:     return '';
1.2       bowersj2  288: }
                    289: 
                    290: sub end_helper {
                    291:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                    292:     
1.3       bowersj2  293:     if ($target ne 'helper') {
                    294:         return '';
                    295:     }
1.7       bowersj2  296: 
1.13      bowersj2  297:     unregisterHelperTags();
1.7       bowersj2  298: 
1.4       bowersj2  299:     return '';
1.2       bowersj2  300: }
1.1       bowersj2  301: 
1.3       bowersj2  302: sub start_state {
                    303:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                    304: 
                    305:     if ($target ne 'helper') {
                    306:         return '';
                    307:     }
                    308: 
1.13      bowersj2  309:     Apache::lonhelper::state->new($token->[2]{'name'},
                    310:                                   $token->[2]{'title'});
1.3       bowersj2  311:     return '';
                    312: }
                    313: 
1.13      bowersj2  314: # Use this to get the param hash from other files.
                    315: sub getParamHash {
                    316:     return $paramHash;
                    317: }
                    318: 
                    319: # Use this to get the helper, if implementing elements in other files
                    320: # (like lonprintout.pm)
                    321: sub getHelper {
                    322:     return $helper;
                    323: }
                    324: 
1.3       bowersj2  325: # don't need this, so ignore it
                    326: sub end_state {
                    327:     return '';
                    328: }
                    329: 
1.1       bowersj2  330: 1;
                    331: 
1.3       bowersj2  332: package Apache::lonhelper::helper;
                    333: 
                    334: use Digest::MD5 qw(md5_hex);
                    335: use HTML::Entities;
                    336: use Apache::loncommon;
                    337: use Apache::File;
                    338: 
                    339: sub new {
                    340:     my $proto = shift;
                    341:     my $class = ref($proto) || $proto;
                    342:     my $self = {};
                    343: 
                    344:     $self->{TITLE} = shift;
                    345:     
1.25      bowersj2  346:     Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});
                    347: 
1.3       bowersj2  348:     # If there is a state from the previous form, use that. If there is no
                    349:     # state, use the start state parameter.
                    350:     if (defined $ENV{"form.CURRENT_STATE"})
                    351:     {
                    352: 	$self->{STATE} = $ENV{"form.CURRENT_STATE"};
                    353:     }
                    354:     else
                    355:     {
                    356: 	$self->{STATE} = "START";
                    357:     }
                    358: 
                    359:     $self->{TOKEN} = $ENV{'form.TOKEN'};
                    360:     # If a token was passed, we load that in. Otherwise, we need to create a 
                    361:     # new storage file
                    362:     # Tried to use standard Tie'd hashes, but you can't seem to take a 
                    363:     # reference to a tied hash and write to it. I'd call that a wart.
                    364:     if ($self->{TOKEN}) {
                    365:         # Validate the token before trusting it
                    366:         if ($self->{TOKEN} !~ /^[a-f0-9]{32}$/) {
                    367:             # Not legit. Return nothing and let all hell break loose.
                    368:             # User shouldn't be doing that!
                    369:             return undef;
                    370:         }
                    371: 
                    372:         # Get the hash.
                    373:         $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN}); # Note the token is not the literal file
                    374:         
                    375:         my $file = Apache::File->new($self->{FILENAME});
                    376:         my $contents = <$file>;
1.5       bowersj2  377: 
                    378:         # Now load in the contents
                    379:         for my $value (split (/&/, $contents)) {
                    380:             my ($name, $value) = split(/=/, $value);
                    381:             $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
                    382:             $self->{VARS}->{$name} = $value;
                    383:         }
                    384: 
1.3       bowersj2  385:         $file->close();
                    386:     } else {
                    387:         # Only valid if we're just starting.
                    388:         if ($self->{STATE} ne 'START') {
                    389:             return undef;
                    390:         }
                    391:         # Must create the storage
                    392:         $self->{TOKEN} = md5_hex($ENV{'user.name'} . $ENV{'user.domain'} .
                    393:                                  time() . rand());
                    394:         $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN});
                    395:     }
                    396: 
                    397:     # OK, we now have our persistent storage.
                    398: 
                    399:     if (defined $ENV{"form.RETURN_PAGE"})
                    400:     {
                    401: 	$self->{RETURN_PAGE} = $ENV{"form.RETURN_PAGE"};
                    402:     }
                    403:     else
                    404:     {
                    405: 	$self->{RETURN_PAGE} = $ENV{REFERER};
                    406:     }
                    407: 
                    408:     $self->{STATES} = {};
                    409:     $self->{DONE} = 0;
                    410: 
1.9       bowersj2  411:     # Used by various helpers for various things; see lonparm.helper
                    412:     # for an example.
                    413:     $self->{DATA} = {};
                    414: 
1.13      bowersj2  415:     $helper = $self;
                    416: 
                    417:     # Establish the $paramHash
                    418:     $paramHash = {};
                    419: 
1.3       bowersj2  420:     bless($self, $class);
                    421:     return $self;
                    422: }
                    423: 
                    424: # Private function; returns a string to construct the hidden fields
                    425: # necessary to have the helper track state.
                    426: sub _saveVars {
                    427:     my $self = shift;
                    428:     my $result = "";
                    429:     $result .= '<input type="hidden" name="CURRENT_STATE" value="' .
                    430:         HTML::Entities::encode($self->{STATE}) . "\" />\n";
                    431:     $result .= '<input type="hidden" name="TOKEN" value="' .
                    432:         $self->{TOKEN} . "\" />\n";
                    433:     $result .= '<input type="hidden" name="RETURN_PAGE" value="' .
                    434:         HTML::Entities::encode($self->{RETURN_PAGE}) . "\" />\n";
                    435: 
                    436:     return $result;
                    437: }
                    438: 
                    439: # Private function: Create the querystring-like representation of the stored
                    440: # data to write to disk.
                    441: sub _varsInFile {
                    442:     my $self = shift;
                    443:     my @vars = ();
                    444:     for my $key (keys %{$self->{VARS}}) {
                    445:         push @vars, &Apache::lonnet::escape($key) . '=' .
                    446:             &Apache::lonnet::escape($self->{VARS}->{$key});
                    447:     }
                    448:     return join ('&', @vars);
                    449: }
                    450: 
1.5       bowersj2  451: # Use this to declare variables.
                    452: # FIXME: Document this
                    453: sub declareVar {
                    454:     my $self = shift;
                    455:     my $var = shift;
                    456: 
                    457:     if (!defined($self->{VARS}->{$var})) {
                    458:         $self->{VARS}->{$var} = '';
                    459:     }
                    460: 
                    461:     my $envname = 'form.' . $var . '.forminput';
                    462:     if (defined($ENV{$envname})) {
                    463:         $self->{VARS}->{$var} = $ENV{$envname};
                    464:     }
                    465: }
                    466: 
1.3       bowersj2  467: sub changeState {
                    468:     my $self = shift;
                    469:     $self->{STATE} = shift;
                    470: }
                    471: 
                    472: sub registerState {
                    473:     my $self = shift;
                    474:     my $state = shift;
                    475: 
                    476:     my $stateName = $state->name();
                    477:     $self->{STATES}{$stateName} = $state;
                    478: }
                    479: 
1.13      bowersj2  480: sub process {
1.3       bowersj2  481:     my $self = shift;
                    482: 
                    483:     # Phase 1: Post processing for state of previous screen (which is actually
                    484:     # the "current state" in terms of the helper variables), if it wasn't the 
                    485:     # beginning state.
                    486:     if ($self->{STATE} ne "START" || $ENV{"form.SUBMIT"} eq "Next ->") {
                    487: 	my $prevState = $self->{STATES}{$self->{STATE}};
1.13      bowersj2  488:         $prevState->postprocess();
1.3       bowersj2  489:     }
                    490:     
                    491:     # Note, to handle errors in a state's input that a user must correct,
                    492:     # do not transition in the postprocess, and force the user to correct
                    493:     # the error.
                    494: 
                    495:     # Phase 2: Preprocess current state
                    496:     my $startState = $self->{STATE};
1.17      bowersj2  497:     my $state = $self->{STATES}->{$startState};
1.3       bowersj2  498:     
1.13      bowersj2  499:     # For debugging, print something here to determine if you're going
                    500:     # to an undefined state.
1.3       bowersj2  501:     if (!defined($state)) {
1.13      bowersj2  502:         return;
1.3       bowersj2  503:     }
                    504:     $state->preprocess();
                    505: 
                    506:     # Phase 3: While the current state is different from the previous state,
                    507:     # keep processing.
1.17      bowersj2  508:     while ( $startState ne $self->{STATE} && 
                    509:             defined($self->{STATES}->{$self->{STATE}}) )
1.3       bowersj2  510:     {
                    511: 	$startState = $self->{STATE};
1.17      bowersj2  512: 	$state = $self->{STATES}->{$startState};
1.3       bowersj2  513: 	$state->preprocess();
                    514:     }
                    515: 
1.13      bowersj2  516:     return;
                    517: } 
                    518: 
                    519: # 1: Do the post processing for the previous state.
                    520: # 2: Do the preprocessing for the current state.
                    521: # 3: Check to see if state changed, if so, postprocess current and move to next.
                    522: #    Repeat until state stays stable.
                    523: # 4: Render the current state to the screen as an HTML page.
                    524: sub display {
                    525:     my $self = shift;
                    526: 
                    527:     my $state = $self->{STATES}{$self->{STATE}};
                    528: 
                    529:     my $result = "";
                    530: 
1.17      bowersj2  531:     if (!defined($state)) {
                    532:         $result = "<font color='#ff0000'>Error: state '$state' not defined!</font>";
                    533:         return $result;
                    534:     }
                    535: 
1.3       bowersj2  536:     # Phase 4: Display.
                    537:     my $stateTitle = $state->title();
                    538:     my $bodytag = &Apache::loncommon::bodytag("$self->{TITLE}",'','');
                    539: 
                    540:     $result .= <<HEADER;
                    541: <html>
                    542:     <head>
                    543:         <title>LON-CAPA Helper: $self->{TITLE}</title>
                    544:     </head>
                    545:     $bodytag
                    546: HEADER
1.14      bowersj2  547:     if (!$state->overrideForm()) { $result.="<form name='helpform' method='GET'>"; }
1.3       bowersj2  548:     $result .= <<HEADER;
                    549:         <table border="0"><tr><td>
                    550:         <h2><i>$stateTitle</i></h2>
                    551: HEADER
                    552: 
                    553:     if (!$state->overrideForm()) {
                    554:         $result .= $self->_saveVars();
                    555:     }
                    556:     $result .= $state->render() . "<p>&nbsp;</p>";
                    557: 
                    558:     if (!$state->overrideForm()) {
                    559:         $result .= '<center>';
                    560:         if ($self->{STATE} ne $self->{START_STATE}) {
                    561:             #$result .= '<input name="SUBMIT" type="submit" value="&lt;- Previous" />&nbsp;&nbsp;';
                    562:         }
                    563:         if ($self->{DONE}) {
                    564:             my $returnPage = $self->{RETURN_PAGE};
                    565:             $result .= "<a href=\"$returnPage\">End Helper</a>";
                    566:         }
                    567:         else {
                    568:             $result .= '<input name="back" type="button" ';
                    569:             $result .= 'value="&lt;- Previous" onclick="history.go(-1)" /> ';
                    570:             $result .= '<input name="SUBMIT" type="submit" value="Next -&gt;" />';
                    571:         }
                    572:         $result .= "</center>\n";
                    573:     }
                    574: 
1.13      bowersj2  575:     #foreach my $key (keys %{$self->{VARS}}) {
                    576:     #    $result .= "|$key| -> " . $self->{VARS}->{$key} . "<br />";
                    577:     #}
1.5       bowersj2  578: 
1.3       bowersj2  579:     $result .= <<FOOTER;
                    580:               </td>
                    581:             </tr>
                    582:           </table>
                    583:         </form>
                    584:     </body>
                    585: </html>
                    586: FOOTER
                    587: 
                    588:     # Handle writing out the vars to the file
                    589:     my $file = Apache::File->new('>'.$self->{FILENAME});
                    590:     print $file $self->_varsInFile();
                    591: 
                    592:     return $result;
                    593: }
                    594: 
                    595: 1;
                    596: 
                    597: package Apache::lonhelper::state;
                    598: 
                    599: # States bundle things together and are responsible for compositing the
1.4       bowersj2  600: # various elements together. It is not generally necessary for users to
                    601: # use the state object directly, so it is not perldoc'ed.
                    602: 
                    603: # Basically, all the states do is pass calls to the elements and aggregate
                    604: # the results.
1.3       bowersj2  605: 
                    606: sub new {
                    607:     my $proto = shift;
                    608:     my $class = ref($proto) || $proto;
                    609:     my $self = {};
                    610: 
                    611:     $self->{NAME} = shift;
                    612:     $self->{TITLE} = shift;
                    613:     $self->{ELEMENTS} = [];
                    614: 
                    615:     bless($self, $class);
                    616: 
                    617:     $helper->registerState($self);
                    618: 
1.13      bowersj2  619:     $state = $self;
                    620: 
1.3       bowersj2  621:     return $self;
                    622: }
                    623: 
                    624: sub name {
                    625:     my $self = shift;
                    626:     return $self->{NAME};
                    627: }
                    628: 
                    629: sub title {
                    630:     my $self = shift;
                    631:     return $self->{TITLE};
                    632: }
                    633: 
1.4       bowersj2  634: sub preprocess {
                    635:     my $self = shift;
                    636:     for my $element (@{$self->{ELEMENTS}}) {
                    637:         $element->preprocess();
                    638:     }
                    639: }
                    640: 
1.6       bowersj2  641: # FIXME: Document that all postprocesses must return a true value or
                    642: # the state transition will be overridden
1.4       bowersj2  643: sub postprocess {
                    644:     my $self = shift;
1.6       bowersj2  645: 
                    646:     # Save the state so we can roll it back if we need to.
                    647:     my $originalState = $helper->{STATE};
                    648:     my $everythingSuccessful = 1;
                    649: 
1.4       bowersj2  650:     for my $element (@{$self->{ELEMENTS}}) {
1.6       bowersj2  651:         my $result = $element->postprocess();
                    652:         if (!$result) { $everythingSuccessful = 0; }
                    653:     }
                    654: 
                    655:     # If not all the postprocesses were successful, override
                    656:     # any state transitions that may have occurred. It is the
                    657:     # responsibility of the states to make sure they have 
                    658:     # error handling in that case.
                    659:     if (!$everythingSuccessful) {
                    660:         $helper->{STATE} = $originalState;
1.4       bowersj2  661:     }
                    662: }
                    663: 
1.13      bowersj2  664: # Override the form if any element wants to.
                    665: # two elements overriding the form will make a mess, but that should
                    666: # be considered helper author error ;-)
1.4       bowersj2  667: sub overrideForm {
1.13      bowersj2  668:     my $self = shift;
                    669:     for my $element (@{$self->{ELEMENTS}}) {
                    670:         if ($element->overrideForm()) {
                    671:             return 1;
                    672:         }
                    673:     }
1.4       bowersj2  674:     return 0;
                    675: }
                    676: 
                    677: sub addElement {
                    678:     my $self = shift;
                    679:     my $element = shift;
                    680:     
                    681:     push @{$self->{ELEMENTS}}, $element;
                    682: }
                    683: 
                    684: sub render {
                    685:     my $self = shift;
                    686:     my @results = ();
                    687: 
                    688:     for my $element (@{$self->{ELEMENTS}}) {
                    689:         push @results, $element->render();
                    690:     }
                    691:     return join("\n", @results);
                    692: }
                    693: 
                    694: 1;
                    695: 
                    696: package Apache::lonhelper::element;
                    697: # Support code for elements
                    698: 
                    699: =pod
                    700: 
                    701: =head2 Element Base Class
                    702: 
                    703: The Apache::lonhelper::element base class provides support methods for
                    704: the elements to use, such as a multiple value processer.
                    705: 
                    706: B<Methods>:
                    707: 
                    708: =over 4
                    709: 
                    710: =item * process_multiple_choices(formName, varName): Process the form 
                    711: element named "formName" and place the selected items into the helper 
                    712: variable named varName. This is for things like checkboxes or 
                    713: multiple-selection listboxes where the user can select more then 
                    714: one entry. The selected entries are delimited by triple pipes in 
1.5       bowersj2  715: the helper variables, like this:  
                    716: 
                    717:  CHOICE_1|||CHOICE_2|||CHOICE_3
1.4       bowersj2  718: 
                    719: =back
                    720: 
1.25      bowersj2  721: B<finalcode tag>
                    722: 
                    723: Each element can contain a "finalcode" tag that, when the special FINAL
                    724: helper state is used, will be executed, surrounded by "sub { my $helper = shift;"
                    725: and "}". It is expected to return a string describing what it did, which 
                    726: may be an empty string. See course initialization helper for an example. This is
                    727: generally intended for helpers like the course initialization helper, which consist
                    728: of several panels, each of which is performing some sort of bite-sized functionality.
                    729: 
                    730: B<defaultvalue tag>
                    731: 
                    732: Each element that accepts user input can contain a "defaultvalue" tag that,
                    733: when surrounded by "sub { my $helper = shift; my $state = shift; " and "}",
                    734: will form a subroutine that when called will provide a default value for
                    735: the element. How this value is interpreted by the element is specific to
                    736: the element itself, and possibly the settings the element has (such as 
                    737: multichoice vs. single choice for <choices> tags). 
                    738: 
                    739: This is also intended for things like the course initialization wizard, where the
                    740: user is setting various parameters. By correctly grabbing current settings 
                    741: and including them into the helper, it allows the user to come back to the
                    742: helper later and re-execute it, without needing to worry about overwriting
                    743: some setting accidentally.
                    744: 
                    745: Again, see the course initialization helper for examples.
                    746: 
1.4       bowersj2  747: =cut
                    748: 
1.5       bowersj2  749: BEGIN {
1.7       bowersj2  750:     &Apache::lonhelper::register('Apache::lonhelper::element',
1.25      bowersj2  751:                                  ('nextstate', 'finalcode',
                    752:                                   'defaultvalue'));
1.5       bowersj2  753: }
                    754: 
1.4       bowersj2  755: # Because we use the param hash, this is often a sufficent
                    756: # constructor
                    757: sub new {
                    758:     my $proto = shift;
                    759:     my $class = ref($proto) || $proto;
                    760:     my $self = $paramHash;
                    761:     bless($self, $class);
                    762: 
                    763:     $self->{PARAMS} = $paramHash;
                    764:     $self->{STATE} = $state;
                    765:     $state->addElement($self);
                    766:     
                    767:     # Ensure param hash is not reused
                    768:     $paramHash = {};
                    769: 
                    770:     return $self;
                    771: }   
                    772: 
1.5       bowersj2  773: sub start_nextstate {
                    774:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                    775: 
                    776:     if ($target ne 'helper') {
                    777:         return '';
                    778:     }
                    779:     
                    780:     $paramHash->{NEXTSTATE} = &Apache::lonxml::get_all_text('/nextstate',
                    781:                                                              $parser);
                    782:     return '';
                    783: }
                    784: 
                    785: sub end_nextstate { return ''; }
                    786: 
1.25      bowersj2  787: sub start_finalcode {
                    788:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                    789: 
                    790:     if ($target ne 'helper') {
                    791:         return '';
                    792:     }
                    793:     
                    794:     $paramHash->{FINAL_CODE} = &Apache::lonxml::get_all_text('/finalcode',
                    795:                                                              $parser);
                    796:     return '';
                    797: }
                    798: 
                    799: sub end_finalcode { return ''; }
                    800: 
                    801: sub start_defaultvalue {
                    802:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                    803: 
                    804:     if ($target ne 'helper') {
                    805:         return '';
                    806:     }
                    807:     
                    808:     $paramHash->{DEFAULT_VALUE} = &Apache::lonxml::get_all_text('/defaultvalue',
                    809:                                                              $parser);
                    810:     $paramHash->{DEFAULT_VALUE} = 'sub { my $helper = shift; my $state = shift;' .
                    811:         $paramHash->{DEFAULT_VALUE} . '}';
                    812:     return '';
                    813: }
                    814: 
                    815: sub end_defaultvalue { return ''; }
                    816: 
1.4       bowersj2  817: sub preprocess {
                    818:     return 1;
                    819: }
                    820: 
                    821: sub postprocess {
                    822:     return 1;
                    823: }
                    824: 
                    825: sub render {
                    826:     return '';
                    827: }
                    828: 
1.13      bowersj2  829: sub overrideForm {
                    830:     return 0;
                    831: }
                    832: 
1.3       bowersj2  833: sub process_multiple_choices {
                    834:     my $self = shift;
                    835:     my $formname = shift;
                    836:     my $var = shift;
                    837: 
1.14      bowersj2  838:     # Must extract values from data directly, as there
                    839:     # may be more then one.
                    840:     my @values;
                    841:     for my $formparam (split (/&/, $ENV{QUERY_STRING})) {
                    842:         my ($name, $value) = split(/=/, $formparam);
                    843:         if ($name ne $formname) {
                    844:             next;
1.3       bowersj2  845:         }
1.14      bowersj2  846:         $value =~ tr/+/ /;
                    847:         $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
                    848:         push @values, $value;
1.3       bowersj2  849:     }
1.14      bowersj2  850:     $helper->{VARS}->{$var} = join('|||', @values);
1.3       bowersj2  851:     
                    852:     return;
                    853: }
                    854: 
1.4       bowersj2  855: 1;
                    856: 
                    857: package Apache::lonhelper::message;
                    858: 
                    859: =pod
                    860: 
                    861: =head2 Element: message
                    862: 
                    863: Message elements display the contents of their <message_text> tags, and
1.5       bowersj2  864: transition directly to the state in the <nextstate> tag. Example:
1.4       bowersj2  865: 
                    866:  <message>
1.5       bowersj2  867:    <nextstate>GET_NAME</nextstate>
1.4       bowersj2  868:    <message_text>This is the <b>message</b> the user will see, 
                    869:                  <i>HTML allowed</i>.</message_text>
                    870:    </message>
                    871: 
1.5       bowersj2  872: This will display the HTML message and transition to the <nextstate> if
1.7       bowersj2  873: given. The HTML will be directly inserted into the helper, so if you don't
1.4       bowersj2  874: want text to run together, you'll need to manually wrap the <message_text>
                    875: in <p> tags, or whatever is appropriate for your HTML.
                    876: 
1.5       bowersj2  877: Message tags do not add in whitespace, so if you want it, you'll need to add
                    878: it into states. This is done so you can inline some elements, such as 
                    879: the <date> element, right between two messages, giving the appearence that 
                    880: the <date> element appears inline. (Note the elements can not be embedded
                    881: within each other.)
                    882: 
1.4       bowersj2  883: This is also a good template for creating your own new states, as it has
                    884: very little code beyond the state template.
                    885: 
                    886: =cut
                    887: 
                    888: no strict;
                    889: @ISA = ("Apache::lonhelper::element");
                    890: use strict;
                    891: 
                    892: BEGIN {
1.7       bowersj2  893:     &Apache::lonhelper::register('Apache::lonhelper::message',
1.10      bowersj2  894:                               ('message'));
1.3       bowersj2  895: }
                    896: 
1.5       bowersj2  897: sub new {
                    898:     my $ref = Apache::lonhelper::element->new();
                    899:     bless($ref);
                    900: }
1.4       bowersj2  901: 
                    902: # CONSTRUCTION: Construct the message element from the XML
                    903: sub start_message {
                    904:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                    905: 
                    906:     if ($target ne 'helper') {
                    907:         return '';
                    908:     }
1.10      bowersj2  909: 
                    910:     $paramHash->{MESSAGE_TEXT} = &Apache::lonxml::get_all_text('/message',
                    911:                                                                $parser);
                    912: 
                    913:     if (defined($token->[2]{'nextstate'})) {
                    914:         $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
                    915:     }
1.4       bowersj2  916:     return '';
1.3       bowersj2  917: }
                    918: 
1.10      bowersj2  919: sub end_message {
1.4       bowersj2  920:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                    921: 
                    922:     if ($target ne 'helper') {
                    923:         return '';
                    924:     }
1.10      bowersj2  925:     Apache::lonhelper::message->new();
                    926:     return '';
1.5       bowersj2  927: }
                    928: 
                    929: sub render {
                    930:     my $self = shift;
                    931: 
                    932:     return $self->{MESSAGE_TEXT};
                    933: }
                    934: # If a NEXTSTATE was given, switch to it
                    935: sub postprocess {
                    936:     my $self = shift;
                    937:     if (defined($self->{NEXTSTATE})) {
                    938:         $helper->changeState($self->{NEXTSTATE});
                    939:     }
1.6       bowersj2  940: 
                    941:     return 1;
1.5       bowersj2  942: }
                    943: 1;
                    944: 
                    945: package Apache::lonhelper::choices;
                    946: 
                    947: =pod
                    948: 
                    949: =head2 Element: choices
                    950: 
                    951: Choice states provide a single choice to the user as a text selection box.
                    952: A "choice" is two pieces of text, one which will be displayed to the user
                    953: (the "human" value), and one which will be passed back to the program
                    954: (the "computer" value). For instance, a human may choose from a list of
                    955: resources on disk by title, while your program wants the file name.
                    956: 
                    957: <choices> takes an attribute "variable" to control which helper variable
                    958: the result is stored in.
                    959: 
                    960: <choices> takes an attribute "multichoice" which, if set to a true
                    961: value, will allow the user to select multiple choices.
                    962: 
1.26    ! bowersj2  963: <choices> takes an attribute "allowempty" which, if set to a true 
        !           964: value, will allow the user to select none of the choices without raising
        !           965: an error message.
        !           966: 
1.5       bowersj2  967: B<SUB-TAGS>
                    968: 
                    969: <choices> can have the following subtags:
                    970: 
                    971: =over 4
                    972: 
                    973: =item * <nextstate>state_name</nextstate>: If given, this will cause the
                    974:       choice element to transition to the given state after executing. If
                    975:       this is used, do not pass nextstates to the <choice> tag.
                    976: 
                    977: =item * <choice />: If the choices are static,
                    978:       this element will allow you to specify them. Each choice
                    979:       contains  attribute, "computer", as described above. The
                    980:       content of the tag will be used as the human label.
                    981:       For example,  
                    982:       <choice computer='234-12-7312'>Bobby McDormik</choice>.
                    983: 
1.13      bowersj2  984:       <choice> can take a parameter "eval", which if set to
                    985:       a true value, will cause the contents of the tag to be
                    986:       evaluated as it would be in an <eval> tag; see <eval> tag
                    987:       below.
                    988: 
1.5       bowersj2  989: <choice> may optionally contain a 'nextstate' attribute, which
                    990: will be the state transisitoned to if the choice is made, if
                    991: the choice is not multichoice.
                    992: 
                    993: =back
                    994: 
                    995: To create the choices programmatically, either wrap the choices in 
                    996: <condition> tags (prefered), or use an <exec> block inside the <choice>
                    997: tag. Store the choices in $state->{CHOICES}, which is a list of list
                    998: references, where each list has three strings. The first is the human
                    999: name, the second is the computer name. and the third is the option
                   1000: next state. For example:
                   1001: 
                   1002:  <exec>
                   1003:     for (my $i = 65; $i < 65 + 26; $i++) {
                   1004:         push @{$state->{CHOICES}}, [chr($i), $i, 'next'];
                   1005:     }
                   1006:  </exec>
                   1007: 
                   1008: This will allow the user to select from the letters A-Z (in ASCII), while
                   1009: passing the ASCII value back into the helper variables, and the state
                   1010: will in all cases transition to 'next'.
                   1011: 
                   1012: You can mix and match methods of creating choices, as long as you always 
                   1013: "push" onto the choice list, rather then wiping it out. (You can even 
                   1014: remove choices programmatically, but that would probably be bad form.)
                   1015: 
1.25      bowersj2 1016: B<defaultvalue support>
                   1017: 
                   1018: Choices supports default values both in multichoice and single choice mode.
                   1019: In single choice mode, have the defaultvalue tag's function return the 
                   1020: computer value of the box you want checked. If the function returns a value
                   1021: that does not correspond to any of the choices, the default behavior of selecting
                   1022: the first choice will be preserved.
                   1023: 
                   1024: For multichoice, return a string with the computer values you want checked,
                   1025: delimited by triple pipes. Note this matches how the result of the <choices>
                   1026: tag is stored in the {VARS} hash.
                   1027: 
1.5       bowersj2 1028: =cut
                   1029: 
                   1030: no strict;
                   1031: @ISA = ("Apache::lonhelper::element");
                   1032: use strict;
                   1033: 
                   1034: BEGIN {
1.7       bowersj2 1035:     &Apache::lonhelper::register('Apache::lonhelper::choices',
1.5       bowersj2 1036:                               ('choice', 'choices'));
                   1037: }
                   1038: 
                   1039: sub new {
                   1040:     my $ref = Apache::lonhelper::element->new();
                   1041:     bless($ref);
                   1042: }
                   1043: 
                   1044: # CONSTRUCTION: Construct the message element from the XML
                   1045: sub start_choices {
                   1046:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1047: 
                   1048:     if ($target ne 'helper') {
                   1049:         return '';
                   1050:     }
                   1051: 
                   1052:     # Need to initialize the choices list, so everything can assume it exists
1.24      sakharuk 1053:     $paramHash->{'variable'} = $token->[2]{'variable'} if (!defined($paramHash->{'variable'}));
1.5       bowersj2 1054:     $helper->declareVar($paramHash->{'variable'});
                   1055:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1.26    ! bowersj2 1056:     $paramHash->{'allowempty'} = $token->[2]{'allowempty'};
1.5       bowersj2 1057:     $paramHash->{CHOICES} = [];
                   1058:     return '';
                   1059: }
                   1060: 
                   1061: sub end_choices {
                   1062:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1063: 
                   1064:     if ($target ne 'helper') {
                   1065:         return '';
                   1066:     }
                   1067:     Apache::lonhelper::choices->new();
                   1068:     return '';
                   1069: }
                   1070: 
                   1071: sub start_choice {
                   1072:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1073: 
                   1074:     if ($target ne 'helper') {
                   1075:         return '';
                   1076:     }
                   1077: 
                   1078:     my $computer = $token->[2]{'computer'};
                   1079:     my $human = &Apache::lonxml::get_all_text('/choice',
                   1080:                                               $parser);
                   1081:     my $nextstate = $token->[2]{'nextstate'};
1.13      bowersj2 1082:     my $evalFlag = $token->[2]{'eval'};
                   1083:     push @{$paramHash->{CHOICES}}, [$human, $computer, $nextstate, 
                   1084:                                     $evalFlag];
1.5       bowersj2 1085:     return '';
                   1086: }
                   1087: 
                   1088: sub end_choice {
                   1089:     return '';
                   1090: }
                   1091: 
                   1092: sub render {
                   1093:     # START HERE: Replace this with correct choices code.
                   1094:     my $self = shift;
                   1095:     my $var = $self->{'variable'};
                   1096:     my $buttons = '';
                   1097:     my $result = '';
                   1098: 
                   1099:     if ($self->{'multichoice'}) {
1.6       bowersj2 1100:         $result .= <<SCRIPT;
1.5       bowersj2 1101: <script>
1.18      bowersj2 1102:     function checkall(value, checkName) {
1.15      bowersj2 1103: 	for (i=0; i<document.forms.helpform.elements.length; i++) {
1.18      bowersj2 1104:             ele = document.forms.helpform.elements[i];
                   1105:             if (ele.name == checkName + '.forminput') {
                   1106:                 document.forms.helpform.elements[i].checked=value;
                   1107:             }
1.5       bowersj2 1108:         }
                   1109:     }
                   1110: </script>
                   1111: SCRIPT
1.25      bowersj2 1112:     }
                   1113: 
                   1114:     # Only print "select all" and "unselect all" if there are five or
                   1115:     # more choices; fewer then that and it looks silly.
                   1116:     if ($self->{'multichoice'} && scalar(@{$self->{CHOICES}}) > 4) {
1.5       bowersj2 1117:         $buttons = <<BUTTONS;
                   1118: <br />
1.18      bowersj2 1119: <input type="button" onclick="checkall(true, '$var')" value="Select All" />
                   1120: <input type="button" onclick="checkall(false, '$var')" value="Unselect All" />
1.6       bowersj2 1121: <br />&nbsp;
1.5       bowersj2 1122: BUTTONS
                   1123:     }
                   1124: 
1.16      bowersj2 1125:     if (defined $self->{ERROR_MSG}) {
1.6       bowersj2 1126:         $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br />';
1.5       bowersj2 1127:     }
                   1128: 
                   1129:     $result .= $buttons;
1.6       bowersj2 1130:     
1.5       bowersj2 1131:     $result .= "<table>\n\n";
                   1132: 
1.25      bowersj2 1133:     my %checkedChoices;
                   1134:     my $checkedChoicesFunc;
                   1135: 
                   1136:     if (defined($self->{DEFAULT_VALUE})) {
                   1137:         $checkedChoicesFunc = eval ($self->{DEFAULT_VALUE});
                   1138:         die 'Error in default value code for variable ' . 
                   1139:             {'variable'} . ', Perl said:' . $@ if $@;
                   1140:     } else {
                   1141:         $checkedChoicesFunc = sub { return ''; };
                   1142:     }
                   1143: 
                   1144:     # Process which choices should be checked.
                   1145:     if ($self->{'multichoice'}) {
                   1146:         for my $selectedChoice (split(/\|\|\|/, (&$checkedChoicesFunc($helper, $self)))) {
                   1147:             $checkedChoices{$selectedChoice} = 1;
                   1148:         }
                   1149:     } else {
                   1150:         # single choice
                   1151:         my $selectedChoice = &$checkedChoicesFunc($helper, $self);
                   1152:         
                   1153:         my $foundChoice = 0;
                   1154:         
                   1155:         # check that the choice is in the list of choices.
                   1156:         for my $choice (@{$self->{CHOICES}}) {
                   1157:             if ($choice->[1] eq $selectedChoice) {
                   1158:                 $checkedChoices{$choice->[1]} = 1;
                   1159:                 $foundChoice = 1;
                   1160:             }
                   1161:         }
                   1162:         
                   1163:         # If we couldn't find the choice, pick the first one 
                   1164:         if (!$foundChoice) {
                   1165:             $checkedChoices{$self->{CHOICES}->[0]->[1]} = 1;
                   1166:         }
                   1167:     }
                   1168: 
1.5       bowersj2 1169:     my $type = "radio";
                   1170:     if ($self->{'multichoice'}) { $type = 'checkbox'; }
                   1171:     foreach my $choice (@{$self->{CHOICES}}) {
                   1172:         $result .= "<tr>\n<td width='20'>&nbsp;</td>\n";
                   1173:         $result .= "<td valign='top'><input type='$type' name='$var.forminput'"
                   1174:             . "' value='" . 
                   1175:             HTML::Entities::encode($choice->[1]) 
                   1176:             . "'";
1.25      bowersj2 1177:         if ($checkedChoices{$choice->[1]}) {
1.5       bowersj2 1178:             $result .= " checked ";
                   1179:         }
1.13      bowersj2 1180:         my $choiceLabel = $choice->[0];
                   1181:         if ($choice->[4]) {  # if we need to evaluate this choice
                   1182:             $choiceLabel = "sub { my $helper = shift; my $state = shift;" .
                   1183:                 $choiceLabel . "}";
                   1184:             $choiceLabel = eval($choiceLabel);
                   1185:             $choiceLabel = &$choiceLabel($helper, $self);
                   1186:         }
                   1187:         $result .= "/></td><td> " . $choiceLabel . "</td></tr>\n";
1.5       bowersj2 1188:     }
                   1189:     $result .= "</table>\n\n\n";
                   1190:     $result .= $buttons;
                   1191: 
                   1192:     return $result;
                   1193: }
                   1194: 
                   1195: # If a NEXTSTATE was given or a nextstate for this choice was
                   1196: # given, switch to it
                   1197: sub postprocess {
                   1198:     my $self = shift;
                   1199:     my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};
                   1200: 
1.26    ! bowersj2 1201:     if (!defined($chosenValue) && !$self->{'allowempty'}) {
1.6       bowersj2 1202:         $self->{ERROR_MSG} = "You must choose one or more choices to" .
                   1203:             " continue.";
                   1204:         return 0;
                   1205:     }
                   1206: 
                   1207:     if ($self->{'multichoice'}) {
                   1208:         $self->process_multiple_choices($self->{'variable'}.'.forminput',
                   1209:                                         $self->{'variable'});
                   1210:     }
                   1211: 
1.5       bowersj2 1212:     if (defined($self->{NEXTSTATE})) {
                   1213:         $helper->changeState($self->{NEXTSTATE});
                   1214:     }
                   1215:     
                   1216:     foreach my $choice (@{$self->{CHOICES}}) {
                   1217:         if ($choice->[1] eq $chosenValue) {
                   1218:             if (defined($choice->[2])) {
                   1219:                 $helper->changeState($choice->[2]);
                   1220:             }
                   1221:         }
                   1222:     }
1.6       bowersj2 1223:     return 1;
1.5       bowersj2 1224: }
                   1225: 1;
                   1226: 
                   1227: package Apache::lonhelper::date;
                   1228: 
                   1229: =pod
                   1230: 
                   1231: =head2 Element: date
                   1232: 
                   1233: Date elements allow the selection of a date with a drop down list.
                   1234: 
                   1235: Date elements can take two attributes:
                   1236: 
                   1237: =over 4
                   1238: 
                   1239: =item * B<variable>: The name of the variable to store the chosen
                   1240:         date in. Required.
                   1241: 
                   1242: =item * B<hoursminutes>: If a true value, the date will show hours
                   1243:         and minutes, as well as month/day/year. If false or missing,
                   1244:         the date will only show the month, day, and year.
                   1245: 
                   1246: =back
                   1247: 
                   1248: Date elements contain only an option <nextstate> tag to determine
                   1249: the next state.
                   1250: 
                   1251: Example:
                   1252: 
                   1253:  <date variable="DUE_DATE" hoursminutes="1">
                   1254:    <nextstate>choose_why</nextstate>
                   1255:    </date>
                   1256: 
                   1257: =cut
                   1258: 
                   1259: no strict;
                   1260: @ISA = ("Apache::lonhelper::element");
                   1261: use strict;
                   1262: 
                   1263: use Time::localtime;
                   1264: 
                   1265: BEGIN {
1.7       bowersj2 1266:     &Apache::lonhelper::register('Apache::lonhelper::date',
1.5       bowersj2 1267:                               ('date'));
                   1268: }
                   1269: 
                   1270: # Don't need to override the "new" from element
                   1271: sub new {
                   1272:     my $ref = Apache::lonhelper::element->new();
                   1273:     bless($ref);
                   1274: }
                   1275: 
                   1276: my @months = ("January", "February", "March", "April", "May", "June", "July",
                   1277: 	      "August", "September", "October", "November", "December");
                   1278: 
                   1279: # CONSTRUCTION: Construct the message element from the XML
                   1280: sub start_date {
                   1281:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1282: 
                   1283:     if ($target ne 'helper') {
                   1284:         return '';
                   1285:     }
                   1286: 
                   1287:     $paramHash->{'variable'} = $token->[2]{'variable'};
                   1288:     $helper->declareVar($paramHash->{'variable'});
                   1289:     $paramHash->{'hoursminutes'} = $token->[2]{'hoursminutes'};
                   1290: }
                   1291: 
                   1292: sub end_date {
                   1293:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1294: 
                   1295:     if ($target ne 'helper') {
                   1296:         return '';
                   1297:     }
                   1298:     Apache::lonhelper::date->new();
                   1299:     return '';
                   1300: }
                   1301: 
                   1302: sub render {
                   1303:     my $self = shift;
                   1304:     my $result = "";
                   1305:     my $var = $self->{'variable'};
                   1306: 
                   1307:     my $date;
                   1308:     
                   1309:     # Default date: The current hour.
                   1310:     $date = localtime();
                   1311:     $date->min(0);
                   1312: 
                   1313:     if (defined $self->{ERROR_MSG}) {
                   1314:         $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
                   1315:     }
                   1316: 
                   1317:     # Month
                   1318:     my $i;
                   1319:     $result .= "<select name='${var}month'>\n";
                   1320:     for ($i = 0; $i < 12; $i++) {
                   1321:         if ($i == $date->mon) {
                   1322:             $result .= "<option value='$i' selected>";
                   1323:         } else {
                   1324:             $result .= "<option value='$i'>";
                   1325:         }
                   1326:         $result .= $months[$i] . "</option>\n";
                   1327:     }
                   1328:     $result .= "</select>\n";
                   1329: 
                   1330:     # Day
                   1331:     $result .= "<select name='${var}day'>\n";
                   1332:     for ($i = 1; $i < 32; $i++) {
                   1333:         if ($i == $date->mday) {
                   1334:             $result .= '<option selected>';
                   1335:         } else {
                   1336:             $result .= '<option>';
                   1337:         }
                   1338:         $result .= "$i</option>\n";
                   1339:     }
                   1340:     $result .= "</select>,\n";
                   1341: 
                   1342:     # Year
                   1343:     $result .= "<select name='${var}year'>\n";
                   1344:     for ($i = 2000; $i < 2030; $i++) { # update this after 64-bit dates
                   1345:         if ($date->year + 1900 == $i) {
                   1346:             $result .= "<option selected>";
                   1347:         } else {
                   1348:             $result .= "<option>";
                   1349:         }
                   1350:         $result .= "$i</option>\n";
                   1351:     }
                   1352:     $result .= "</select>,\n";
                   1353: 
                   1354:     # Display Hours and Minutes if they are called for
                   1355:     if ($self->{'hoursminutes'}) {
                   1356:         # Build hour
                   1357:         $result .= "<select name='${var}hour'>\n";
                   1358:         $result .= "<option " . ($date->hour == 0 ? 'selected ':'') .
                   1359:             " value='0'>midnight</option>\n";
                   1360:         for ($i = 1; $i < 12; $i++) {
                   1361:             if ($date->hour == $i) {
                   1362:                 $result .= "<option selected value='$i'>$i a.m.</option>\n";
                   1363:             } else {
                   1364:                 $result .= "<option value='$i'>$i a.m</option>\n";
                   1365:             }
                   1366:         }
                   1367:         $result .= "<option " . ($date->hour == 12 ? 'selected ':'') .
                   1368:             " value='12'>noon</option>\n";
                   1369:         for ($i = 13; $i < 24; $i++) {
                   1370:             my $printedHour = $i - 12;
                   1371:             if ($date->hour == $i) {
                   1372:                 $result .= "<option selected value='$i'>$printedHour p.m.</option>\n";
                   1373:             } else {
                   1374:                 $result .= "<option value='$i'>$printedHour p.m.</option>\n";
                   1375:             }
                   1376:         }
                   1377: 
                   1378:         $result .= "</select> :\n";
                   1379: 
                   1380:         $result .= "<select name='${var}minute'>\n";
                   1381:         for ($i = 0; $i < 60; $i++) {
                   1382:             my $printedMinute = $i;
                   1383:             if ($i < 10) {
                   1384:                 $printedMinute = "0" . $printedMinute;
                   1385:             }
                   1386:             if ($date->min == $i) {
                   1387:                 $result .= "<option selected>";
                   1388:             } else {
                   1389:                 $result .= "<option>";
                   1390:             }
                   1391:             $result .= "$printedMinute</option>\n";
                   1392:         }
                   1393:         $result .= "</select>\n";
                   1394:     }
                   1395: 
                   1396:     return $result;
                   1397: 
                   1398: }
                   1399: # If a NEXTSTATE was given, switch to it
                   1400: sub postprocess {
                   1401:     my $self = shift;
                   1402:     my $var = $self->{'variable'};
                   1403:     my $month = $ENV{'form.' . $var . 'month'}; 
                   1404:     my $day = $ENV{'form.' . $var . 'day'}; 
                   1405:     my $year = $ENV{'form.' . $var . 'year'}; 
                   1406:     my $min = 0; 
                   1407:     my $hour = 0;
                   1408:     if ($self->{'hoursminutes'}) {
                   1409:         $min = $ENV{'form.' . $var . 'minute'};
                   1410:         $hour = $ENV{'form.' . $var . 'hour'};
                   1411:     }
                   1412: 
                   1413:     my $chosenDate = Time::Local::timelocal(0, $min, $hour, $day, $month, $year);
                   1414:     # Check to make sure that the date was not automatically co-erced into a 
                   1415:     # valid date, as we want to flag that as an error
                   1416:     # This happens for "Feb. 31", for instance, which is coerced to March 2 or
                   1417:     # 3, depending on if it's a leapyear
                   1418:     my $checkDate = localtime($chosenDate);
                   1419: 
                   1420:     if ($checkDate->mon != $month || $checkDate->mday != $day ||
                   1421:         $checkDate->year + 1900 != $year) {
                   1422:         $self->{ERROR_MSG} = "Can't use " . $months[$month] . " $day, $year as a "
                   1423:             . "date because it doesn't exist. Please enter a valid date.";
1.6       bowersj2 1424:         return 0;
1.5       bowersj2 1425:     }
                   1426: 
                   1427:     $helper->{VARS}->{$var} = $chosenDate;
                   1428: 
                   1429:     if (defined($self->{NEXTSTATE})) {
                   1430:         $helper->changeState($self->{NEXTSTATE});
                   1431:     }
1.6       bowersj2 1432: 
                   1433:     return 1;
1.5       bowersj2 1434: }
                   1435: 1;
                   1436: 
                   1437: package Apache::lonhelper::resource;
                   1438: 
                   1439: =pod
                   1440: 
                   1441: =head2 Element: resource
                   1442: 
                   1443: <resource> elements allow the user to select one or multiple resources
                   1444: from the current course. You can filter out which resources they can view,
                   1445: and filter out which resources they can select. The course will always
                   1446: be displayed fully expanded, because of the difficulty of maintaining
                   1447: selections across folder openings and closings. If this is fixed, then
                   1448: the user can manipulate the folders.
                   1449: 
                   1450: <resource> takes the standard variable attribute to control what helper
                   1451: variable stores the results. It also takes a "multichoice" attribute,
1.17      bowersj2 1452: which controls whether the user can select more then one resource. The 
                   1453: "toponly" attribute controls whether the resource display shows just the
                   1454: resources in that sequence, or recurses into all sub-sequences, defaulting
                   1455: to false.
1.5       bowersj2 1456: 
                   1457: B<SUB-TAGS>
                   1458: 
                   1459: =over 4
                   1460: 
                   1461: =item * <filterfunc>: If you want to filter what resources are displayed
                   1462:   to the user, use a filter func. The <filterfunc> tag should contain
                   1463:   Perl code that when wrapped with "sub { my $res = shift; " and "}" is 
                   1464:   a function that returns true if the resource should be displayed, 
                   1465:   and false if it should be skipped. $res is a resource object. 
                   1466:   (See Apache::lonnavmaps documentation for information about the 
                   1467:   resource object.)
                   1468: 
                   1469: =item * <choicefunc>: Same as <filterfunc>, except that controls whether
                   1470:   the given resource can be chosen. (It is almost always a good idea to
                   1471:   show the user the folders, for instance, but you do not always want to 
                   1472:   let the user select them.)
                   1473: 
                   1474: =item * <nextstate>: Standard nextstate behavior.
                   1475: 
                   1476: =item * <valuefunc>: This function controls what is returned by the resource
                   1477:   when the user selects it. Like filterfunc and choicefunc, it should be
                   1478:   a function fragment that when wrapped by "sub { my $res = shift; " and
                   1479:   "}" returns a string representing what you want to have as the value. By
                   1480:   default, the value will be the resource ID of the object ($res->{ID}).
                   1481: 
1.13      bowersj2 1482: =item * <mapurl>: If the URL of a map is given here, only that map
                   1483:   will be displayed, instead of the whole course.
                   1484: 
1.5       bowersj2 1485: =back
                   1486: 
                   1487: =cut
                   1488: 
                   1489: no strict;
                   1490: @ISA = ("Apache::lonhelper::element");
                   1491: use strict;
                   1492: 
                   1493: BEGIN {
1.7       bowersj2 1494:     &Apache::lonhelper::register('Apache::lonhelper::resource',
1.5       bowersj2 1495:                               ('resource', 'filterfunc', 
1.13      bowersj2 1496:                                'choicefunc', 'valuefunc',
                   1497:                                'mapurl'));
1.5       bowersj2 1498: }
                   1499: 
                   1500: sub new {
                   1501:     my $ref = Apache::lonhelper::element->new();
                   1502:     bless($ref);
                   1503: }
                   1504: 
                   1505: # CONSTRUCTION: Construct the message element from the XML
                   1506: sub start_resource {
                   1507:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1508: 
                   1509:     if ($target ne 'helper') {
                   1510:         return '';
                   1511:     }
                   1512: 
                   1513:     $paramHash->{'variable'} = $token->[2]{'variable'};
                   1514:     $helper->declareVar($paramHash->{'variable'});
1.14      bowersj2 1515:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1.17      bowersj2 1516:     $paramHash->{'toponly'} = $token->[2]{'toponly'};
1.5       bowersj2 1517:     return '';
                   1518: }
                   1519: 
                   1520: sub end_resource {
                   1521:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1522: 
                   1523:     if ($target ne 'helper') {
                   1524:         return '';
                   1525:     }
                   1526:     if (!defined($paramHash->{FILTER_FUNC})) {
                   1527:         $paramHash->{FILTER_FUNC} = sub {return 1;};
                   1528:     }
                   1529:     if (!defined($paramHash->{CHOICE_FUNC})) {
                   1530:         $paramHash->{CHOICE_FUNC} = sub {return 1;};
                   1531:     }
                   1532:     if (!defined($paramHash->{VALUE_FUNC})) {
                   1533:         $paramHash->{VALUE_FUNC} = sub {my $res = shift; return $res->{ID}; };
                   1534:     }
                   1535:     Apache::lonhelper::resource->new();
1.4       bowersj2 1536:     return '';
                   1537: }
                   1538: 
1.5       bowersj2 1539: sub start_filterfunc {
                   1540:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1541: 
                   1542:     if ($target ne 'helper') {
                   1543:         return '';
                   1544:     }
                   1545: 
                   1546:     my $contents = Apache::lonxml::get_all_text('/filterfunc',
                   1547:                                                 $parser);
                   1548:     $contents = 'sub { my $res = shift; ' . $contents . '}';
                   1549:     $paramHash->{FILTER_FUNC} = eval $contents;
                   1550: }
                   1551: 
                   1552: sub end_filterfunc { return ''; }
                   1553: 
                   1554: sub start_choicefunc {
                   1555:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1556: 
                   1557:     if ($target ne 'helper') {
                   1558:         return '';
                   1559:     }
                   1560: 
                   1561:     my $contents = Apache::lonxml::get_all_text('/choicefunc',
                   1562:                                                 $parser);
                   1563:     $contents = 'sub { my $res = shift; ' . $contents . '}';
                   1564:     $paramHash->{CHOICE_FUNC} = eval $contents;
                   1565: }
                   1566: 
                   1567: sub end_choicefunc { return ''; }
                   1568: 
                   1569: sub start_valuefunc {
                   1570:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1571: 
                   1572:     if ($target ne 'helper') {
                   1573:         return '';
                   1574:     }
                   1575: 
                   1576:     my $contents = Apache::lonxml::get_all_text('/valuefunc',
                   1577:                                                 $parser);
                   1578:     $contents = 'sub { my $res = shift; ' . $contents . '}';
                   1579:     $paramHash->{VALUE_FUNC} = eval $contents;
                   1580: }
                   1581: 
                   1582: sub end_valuefunc { return ''; }
                   1583: 
1.13      bowersj2 1584: sub start_mapurl {
                   1585:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1586: 
                   1587:     if ($target ne 'helper') {
                   1588:         return '';
                   1589:     }
                   1590: 
                   1591:     my $contents = Apache::lonxml::get_all_text('/mapurl',
                   1592:                                                 $parser);
1.14      bowersj2 1593:     $paramHash->{MAP_URL} = $contents;
1.13      bowersj2 1594: }
                   1595: 
                   1596: sub end_mapurl { return ''; }
                   1597: 
1.5       bowersj2 1598: # A note, in case I don't get to this before I leave.
                   1599: # If someone complains about the "Back" button returning them
                   1600: # to the previous folder state, instead of returning them to
                   1601: # the previous helper state, the *correct* answer is for the helper
                   1602: # to keep track of how many times the user has manipulated the folders,
                   1603: # and feed that to the history.go() call in the helper rendering routines.
                   1604: # If done correctly, the helper itself can keep track of how many times
                   1605: # it renders the same states, so it doesn't go in just this state, and
                   1606: # you can lean on the browser back button to make sure it all chains
                   1607: # correctly.
                   1608: # Right now, though, I'm just forcing all folders open.
                   1609: 
                   1610: sub render {
                   1611:     my $self = shift;
                   1612:     my $result = "";
                   1613:     my $var = $self->{'variable'};
                   1614:     my $curVal = $helper->{VARS}->{$var};
                   1615: 
1.15      bowersj2 1616:     my $buttons = '';
                   1617: 
                   1618:     if ($self->{'multichoice'}) {
                   1619:         $result = <<SCRIPT;
                   1620: <script>
1.18      bowersj2 1621:     function checkall(value, checkName) {
1.15      bowersj2 1622: 	for (i=0; i<document.forms.helpform.elements.length; i++) {
                   1623:             ele = document.forms.helpform.elements[i];
1.18      bowersj2 1624:             if (ele.name == checkName + '.forminput') {
1.15      bowersj2 1625:                 document.forms.helpform.elements[i].checked=value;
                   1626:             }
                   1627:         }
                   1628:     }
                   1629: </script>
                   1630: SCRIPT
                   1631:         $buttons = <<BUTTONS;
                   1632: <br /> &nbsp;
1.18      bowersj2 1633: <input type="button" onclick="checkall(true, '$var')" value="Select All Resources" />
                   1634: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Resources" />
1.15      bowersj2 1635: <br /> &nbsp;
                   1636: BUTTONS
                   1637:     }
                   1638: 
1.5       bowersj2 1639:     if (defined $self->{ERROR_MSG}) {
1.14      bowersj2 1640:         $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1.5       bowersj2 1641:     }
                   1642: 
1.15      bowersj2 1643:     $result .= $buttons;
                   1644: 
1.5       bowersj2 1645:     my $filterFunc = $self->{FILTER_FUNC};
                   1646:     my $choiceFunc = $self->{CHOICE_FUNC};
                   1647:     my $valueFunc = $self->{VALUE_FUNC};
1.13      bowersj2 1648:     my $mapUrl = $self->{MAP_URL};
1.14      bowersj2 1649:     my $multichoice = $self->{'multichoice'};
1.5       bowersj2 1650: 
                   1651:     # Create the composite function that renders the column on the nav map
                   1652:     # have to admit any language that lets me do this can't be all bad
                   1653:     #  - Jeremy (Pythonista) ;-)
                   1654:     my $checked = 0;
                   1655:     my $renderColFunc = sub {
                   1656:         my ($resource, $part, $params) = @_;
1.14      bowersj2 1657: 
                   1658:         my $inputType;
                   1659:         if ($multichoice) { $inputType = 'checkbox'; }
                   1660:         else {$inputType = 'radio'; }
                   1661: 
1.5       bowersj2 1662:         if (!&$choiceFunc($resource)) {
                   1663:             return '<td>&nbsp;</td>';
                   1664:         } else {
1.14      bowersj2 1665:             my $col = "<td><input type='$inputType' name='${var}.forminput' ";
                   1666:             if (!$checked && !$multichoice) {
1.5       bowersj2 1667:                 $col .= "checked ";
                   1668:                 $checked = 1;
                   1669:             }
                   1670:             $col .= "value='" . 
                   1671:                 HTML::Entities::encode(&$valueFunc($resource)) 
                   1672:                 . "' /></td>";
                   1673:             return $col;
                   1674:         }
                   1675:     };
                   1676: 
1.17      bowersj2 1677:     $ENV{'form.condition'} = !$self->{'toponly'};
1.5       bowersj2 1678:     $result .= 
                   1679:         &Apache::lonnavmaps::render( { 'cols' => [$renderColFunc, 
                   1680:                                                   Apache::lonnavmaps::resource()],
                   1681:                                        'showParts' => 0,
                   1682:                                        'filterFunc' => $filterFunc,
1.13      bowersj2 1683:                                        'resource_no_folder_link' => 1,
                   1684:                                        'iterator_map' => $mapUrl }
1.5       bowersj2 1685:                                        );
1.15      bowersj2 1686: 
                   1687:     $result .= $buttons;
1.5       bowersj2 1688:                                                 
                   1689:     return $result;
                   1690: }
                   1691:     
                   1692: sub postprocess {
                   1693:     my $self = shift;
1.14      bowersj2 1694: 
                   1695:     if ($self->{'multichoice'}) {
                   1696:         $self->process_multiple_choices($self->{'variable'}.'.forminput',
                   1697:                                         $self->{'variable'});
                   1698:     }
                   1699: 
                   1700:     if ($self->{'multichoice'} && !$helper->{VARS}->{$self->{'variable'}}) {
                   1701:         $self->{ERROR_MSG} = 'You must choose at least one resource to continue.';
                   1702:         return 0;
                   1703:     }
                   1704: 
1.5       bowersj2 1705:     if (defined($self->{NEXTSTATE})) {
                   1706:         $helper->changeState($self->{NEXTSTATE});
                   1707:     }
1.6       bowersj2 1708: 
                   1709:     return 1;
1.5       bowersj2 1710: }
                   1711: 
                   1712: 1;
                   1713: 
                   1714: package Apache::lonhelper::student;
                   1715: 
                   1716: =pod
                   1717: 
                   1718: =head2 Element: student
                   1719: 
                   1720: Student elements display a choice of students enrolled in the current
                   1721: course. Currently it is primitive; this is expected to evolve later.
                   1722: 
                   1723: Student elements take two attributes: "variable", which means what
                   1724: it usually does, and "multichoice", which if true allows the user
                   1725: to select multiple students.
                   1726: 
                   1727: =cut
                   1728: 
                   1729: no strict;
                   1730: @ISA = ("Apache::lonhelper::element");
                   1731: use strict;
                   1732: 
                   1733: 
                   1734: 
                   1735: BEGIN {
1.7       bowersj2 1736:     &Apache::lonhelper::register('Apache::lonhelper::student',
1.5       bowersj2 1737:                               ('student'));
                   1738: }
                   1739: 
                   1740: sub new {
                   1741:     my $ref = Apache::lonhelper::element->new();
                   1742:     bless($ref);
                   1743: }
1.4       bowersj2 1744: 
1.5       bowersj2 1745: sub start_student {
1.4       bowersj2 1746:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1747: 
                   1748:     if ($target ne 'helper') {
                   1749:         return '';
                   1750:     }
                   1751: 
1.5       bowersj2 1752:     $paramHash->{'variable'} = $token->[2]{'variable'};
                   1753:     $helper->declareVar($paramHash->{'variable'});
                   1754:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1.12      bowersj2 1755:     if (defined($token->[2]{'nextstate'})) {
                   1756:         $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
                   1757:     }
                   1758:     
1.5       bowersj2 1759: }    
                   1760: 
                   1761: sub end_student {
                   1762:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1763: 
                   1764:     if ($target ne 'helper') {
                   1765:         return '';
                   1766:     }
                   1767:     Apache::lonhelper::student->new();
1.3       bowersj2 1768: }
1.5       bowersj2 1769: 
                   1770: sub render {
                   1771:     my $self = shift;
                   1772:     my $result = '';
                   1773:     my $buttons = '';
1.18      bowersj2 1774:     my $var = $self->{'variable'};
1.5       bowersj2 1775: 
                   1776:     if ($self->{'multichoice'}) {
                   1777:         $result = <<SCRIPT;
                   1778: <script>
1.18      bowersj2 1779:     function checkall(value, checkName) {
1.15      bowersj2 1780: 	for (i=0; i<document.forms.helpform.elements.length; i++) {
1.18      bowersj2 1781:             ele = document.forms.helpform.elements[i];
                   1782:             if (ele.name == checkName + '.forminput') {
                   1783:                 document.forms.helpform.elements[i].checked=value;
                   1784:             }
1.5       bowersj2 1785:         }
                   1786:     }
                   1787: </script>
                   1788: SCRIPT
                   1789:         $buttons = <<BUTTONS;
                   1790: <br />
1.18      bowersj2 1791: <input type="button" onclick="checkall(true, '$var')" value="Select All Students" />
                   1792: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Students" />
1.5       bowersj2 1793: <br />
                   1794: BUTTONS
                   1795:     }
                   1796: 
                   1797:     if (defined $self->{ERROR_MSG}) {
                   1798:         $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
                   1799:     }
                   1800: 
                   1801:     # Load up the students
                   1802:     my $choices = &Apache::loncoursedata::get_classlist();
                   1803:     my @keys = keys %{$choices};
                   1804: 
                   1805:     # Constants
                   1806:     my $section = Apache::loncoursedata::CL_SECTION();
                   1807:     my $fullname = Apache::loncoursedata::CL_FULLNAME();
                   1808: 
                   1809:     # Sort by: Section, name
                   1810:     @keys = sort {
                   1811:         if ($choices->{$a}->[$section] ne $choices->{$b}->[$section]) {
                   1812:             return $choices->{$a}->[$section] cmp $choices->{$b}->[$section];
                   1813:         }
                   1814:         return $choices->{$a}->[$fullname] cmp $choices->{$b}->[$fullname];
                   1815:     } @keys;
                   1816: 
                   1817:     my $type = 'radio';
                   1818:     if ($self->{'multichoice'}) { $type = 'checkbox'; }
                   1819:     $result .= "<table cellspacing='2' cellpadding='2' border='0'>\n";
                   1820:     $result .= "<tr><td></td><td align='center'><b>Student Name</b></td>".
                   1821:         "<td align='center'><b>Section</b></td></tr>";
                   1822: 
                   1823:     my $checked = 0;
                   1824:     foreach (@keys) {
                   1825:         $result .= "<tr><td><input type='$type' name='" .
                   1826:             $self->{'variable'} . '.forminput' . "'";
                   1827:             
                   1828:         if (!$self->{'multichoice'} && !$checked) {
                   1829:             $result .= " checked ";
                   1830:             $checked = 1;
                   1831:         }
                   1832:         $result .=
1.19      bowersj2 1833:             " value='" . HTML::Entities::encode($_ . ':' . $choices->{$_}->[$section])
1.5       bowersj2 1834:             . "' /></td><td>"
                   1835:             . HTML::Entities::encode($choices->{$_}->[$fullname])
                   1836:             . "</td><td align='center'>" 
                   1837:             . HTML::Entities::encode($choices->{$_}->[$section])
                   1838:             . "</td></tr>\n";
                   1839:     }
                   1840: 
                   1841:     $result .= "</table>\n\n";
                   1842:     $result .= $buttons;    
1.4       bowersj2 1843:     
1.5       bowersj2 1844:     return $result;
                   1845: }
                   1846: 
1.6       bowersj2 1847: sub postprocess {
                   1848:     my $self = shift;
                   1849: 
                   1850:     my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
                   1851:     if (!$result) {
                   1852:         $self->{ERROR_MSG} = 'You must choose at least one student '.
                   1853:             'to continue.';
                   1854:         return 0;
                   1855:     }
                   1856: 
                   1857:     if ($self->{'multichoice'}) {
                   1858:         $self->process_multiple_choices($self->{'variable'}.'.forminput',
                   1859:                                         $self->{'variable'});
                   1860:     }
                   1861:     if (defined($self->{NEXTSTATE})) {
                   1862:         $helper->changeState($self->{NEXTSTATE});
                   1863:     }
                   1864: 
                   1865:     return 1;
                   1866: }
                   1867: 
1.5       bowersj2 1868: 1;
                   1869: 
                   1870: package Apache::lonhelper::files;
                   1871: 
                   1872: =pod
                   1873: 
                   1874: =head2 Element: files
                   1875: 
                   1876: files allows the users to choose files from a given directory on the
                   1877: server. It is always multichoice and stores the result as a triple-pipe
                   1878: delimited entry in the helper variables. 
                   1879: 
                   1880: Since it is extremely unlikely that you can actually code a constant
                   1881: representing the directory you wish to allow the user to search, <files>
                   1882: takes a subroutine that returns the name of the directory you wish to
                   1883: have the user browse.
                   1884: 
                   1885: files accepts the attribute "variable" to control where the files chosen
                   1886: are put. It accepts the attribute "multichoice" as the other attribute,
                   1887: defaulting to false, which if true will allow the user to select more
                   1888: then one choice. 
                   1889: 
                   1890: <files> accepts three subtags. One is the "nextstate" sub-tag that works
                   1891: as it does with the other tags. Another is a <filechoice> sub tag that
                   1892: is Perl code that, when surrounded by "sub {" and "}" will return a
                   1893: string representing what directory on the server to allow the user to 
                   1894: choose files from. Finally, the <filefilter> subtag should contain Perl
                   1895: code that when surrounded by "sub { my $filename = shift; " and "}",
                   1896: returns a true value if the user can pick that file, or false otherwise.
                   1897: The filename passed to the function will be just the name of the file, 
                   1898: with no path info.
                   1899: 
                   1900: =cut
                   1901: 
                   1902: no strict;
                   1903: @ISA = ("Apache::lonhelper::element");
                   1904: use strict;
                   1905: 
                   1906: BEGIN {
1.7       bowersj2 1907:     &Apache::lonhelper::register('Apache::lonhelper::files',
                   1908:                                  ('files', 'filechoice', 'filefilter'));
1.5       bowersj2 1909: }
                   1910: 
                   1911: sub new {
                   1912:     my $ref = Apache::lonhelper::element->new();
                   1913:     bless($ref);
                   1914: }
                   1915: 
                   1916: sub start_files {
                   1917:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1918: 
                   1919:     if ($target ne 'helper') {
                   1920:         return '';
                   1921:     }
                   1922:     $paramHash->{'variable'} = $token->[2]{'variable'};
                   1923:     $helper->declareVar($paramHash->{'variable'});
                   1924:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
                   1925: }    
                   1926: 
                   1927: sub end_files {
                   1928:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1929: 
                   1930:     if ($target ne 'helper') {
                   1931:         return '';
                   1932:     }
                   1933:     if (!defined($paramHash->{FILTER_FUNC})) {
                   1934:         $paramHash->{FILTER_FUNC} = sub { return 1; };
                   1935:     }
                   1936:     Apache::lonhelper::files->new();
                   1937: }    
                   1938: 
                   1939: sub start_filechoice {
                   1940:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1941: 
                   1942:     if ($target ne 'helper') {
                   1943:         return '';
                   1944:     }
                   1945:     $paramHash->{'filechoice'} = Apache::lonxml::get_all_text('/filechoice',
                   1946:                                                               $parser);
                   1947: }
                   1948: 
                   1949: sub end_filechoice { return ''; }
                   1950: 
                   1951: sub start_filefilter {
                   1952:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   1953: 
                   1954:     if ($target ne 'helper') {
                   1955:         return '';
                   1956:     }
                   1957: 
                   1958:     my $contents = Apache::lonxml::get_all_text('/filefilter',
                   1959:                                                 $parser);
                   1960:     $contents = 'sub { my $filename = shift; ' . $contents . '}';
                   1961:     $paramHash->{FILTER_FUNC} = eval $contents;
                   1962: }
                   1963: 
                   1964: sub end_filefilter { return ''; }
1.3       bowersj2 1965: 
                   1966: sub render {
                   1967:     my $self = shift;
1.5       bowersj2 1968:     my $result = '';
                   1969:     my $var = $self->{'variable'};
                   1970:     
                   1971:     my $subdirFunc = eval('sub {' . $self->{'filechoice'} . '}');
1.11      bowersj2 1972:     die 'Error in resource filter code for variable ' . 
                   1973:         {'variable'} . ', Perl said:' . $@ if $@;
                   1974: 
1.5       bowersj2 1975:     my $subdir = &$subdirFunc();
                   1976: 
                   1977:     my $filterFunc = $self->{FILTER_FUNC};
                   1978:     my $buttons = '';
1.22      bowersj2 1979:     my $type = 'radio';
                   1980:     if ($self->{'multichoice'}) {
                   1981:         $type = 'checkbox';
                   1982:     }
1.5       bowersj2 1983: 
                   1984:     if ($self->{'multichoice'}) {
                   1985:         $result = <<SCRIPT;
                   1986: <script>
1.18      bowersj2 1987:     function checkall(value, checkName) {
1.15      bowersj2 1988: 	for (i=0; i<document.forms.helpform.elements.length; i++) {
                   1989:             ele = document.forms.helpform.elements[i];
1.18      bowersj2 1990:             if (ele.name == checkName + '.forminput') {
1.15      bowersj2 1991:                 document.forms.helpform.elements[i].checked=value;
1.5       bowersj2 1992:             }
                   1993:         }
                   1994:     }
1.21      bowersj2 1995: 
1.22      bowersj2 1996:     function checkallclass(value, className) {
1.21      bowersj2 1997:         for (i=0; i<document.forms.helpform.elements.length; i++) {
                   1998:             ele = document.forms.helpform.elements[i];
1.22      bowersj2 1999:             if (ele.type == "$type" && ele.onclick) {
1.21      bowersj2 2000:                 document.forms.helpform.elements[i].checked=value;
                   2001:             }
                   2002:         }
                   2003:     }
1.5       bowersj2 2004: </script>
                   2005: SCRIPT
1.15      bowersj2 2006:         $buttons = <<BUTTONS;
1.5       bowersj2 2007: <br /> &nbsp;
1.18      bowersj2 2008: <input type="button" onclick="checkall(true, '$var')" value="Select All Files" />
                   2009: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Files" />
1.23      bowersj2 2010: BUTTONS
                   2011: 
                   2012:         if ($helper->{VARS}->{'construction'}) {
                   2013:             $buttons .= <<BUTTONS;
1.22      bowersj2 2014: <input type="button" onclick="checkallclass(true, 'Published')" value="Select All Published" />
                   2015: <input type="button" onclick="checkallclass(false, 'Published')" value="Unselect All Published" />
1.5       bowersj2 2016: <br /> &nbsp;
                   2017: BUTTONS
1.23      bowersj2 2018:        }
1.5       bowersj2 2019:     }
                   2020: 
                   2021:     # Get the list of files in this directory.
                   2022:     my @fileList;
                   2023: 
                   2024:     # If the subdirectory is in local CSTR space
                   2025:     if ($subdir =~ m|/home/([^/]+)/public_html|) {
                   2026:         my $user = $1;
                   2027:         my $domain = $Apache::lonnet::perlvar{'lonDefDomain'};
                   2028:         @fileList = &Apache::lonnet::dirlist($subdir, $domain, $user, '');
                   2029:     } else {
                   2030:         # local library server resource space
                   2031:         @fileList = &Apache::lonnet::dirlist($subdir, $ENV{'user.domain'}, $ENV{'user.name'}, '');
                   2032:     }
1.3       bowersj2 2033: 
1.5       bowersj2 2034:     $result .= $buttons;
                   2035: 
1.6       bowersj2 2036:     if (defined $self->{ERROR_MSG}) {
                   2037:         $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
                   2038:     }
                   2039: 
1.20      bowersj2 2040:     $result .= '<table border="0" cellpadding="2" cellspacing="0">';
1.5       bowersj2 2041: 
                   2042:     # Keeps track if there are no choices, prints appropriate error
                   2043:     # if there are none. 
                   2044:     my $choices = 0;
                   2045:     # Print each legitimate file choice.
                   2046:     for my $file (@fileList) {
                   2047:         $file = (split(/&/, $file))[0];
                   2048:         if ($file eq '.' || $file eq '..') {
                   2049:             next;
                   2050:         }
                   2051:         my $fileName = $subdir .'/'. $file;
                   2052:         if (&$filterFunc($file)) {
1.24      sakharuk 2053: 	    my $status;
                   2054: 	    my $color;
                   2055: 	    if ($helper->{VARS}->{'construction'}) {
                   2056: 		($status, $color) = @{fileState($subdir, $file)};
                   2057: 	    } else {
                   2058: 		$status = '';
                   2059: 		$color = '';
                   2060: 	    }
1.22      bowersj2 2061: 
                   2062:             # Netscape 4 is stupid and there's nowhere to put the
                   2063:             # information on the input tag that the file is Published,
                   2064:             # Unpublished, etc. In *real* browsers we can just say
                   2065:             # "class='Published'" and check the className attribute of
                   2066:             # the input tag, but Netscape 4 is too stupid to understand
                   2067:             # that attribute, and un-comprehended attributes are not
                   2068:             # reflected into the object model. So instead, what I do 
                   2069:             # is either have or don't have an "onclick" handler that 
                   2070:             # does nothing, give Published files the onclick handler, and
                   2071:             # have the checker scripts check for that. Stupid and clumsy,
                   2072:             # and only gives us binary "yes/no" information (at least I
                   2073:             # couldn't figure out how to reach into the event handler's
                   2074:             # actual code to retreive a value), but it works well enough
                   2075:             # here.
1.23      bowersj2 2076:         
1.22      bowersj2 2077:             my $onclick = '';
1.23      bowersj2 2078:             if ($status eq 'Published' && $helper->{VARS}->{'construction'}) {
1.22      bowersj2 2079:                 $onclick = 'onclick="a=1" ';
                   2080:             }
1.20      bowersj2 2081:             $result .= '<tr><td align="right"' . " bgcolor='$color'>" .
1.22      bowersj2 2082:                 "<input $onclick type='$type' name='" . $var
1.5       bowersj2 2083:             . ".forminput' value='" . HTML::Entities::encode($fileName) .
                   2084:                 "'";
                   2085:             if (!$self->{'multichoice'} && $choices == 0) {
                   2086:                 $result .= ' checked';
                   2087:             }
1.20      bowersj2 2088:             $result .= "/></td><td bgcolor='$color'>" . $file .
                   2089:                  "</td><td bgcolor='$color'>$status</td></tr>\n";
1.5       bowersj2 2090:             $choices++;
                   2091:         }
                   2092:     }
                   2093: 
                   2094:     $result .= "</table>\n";
                   2095: 
                   2096:     if (!$choices) {
                   2097:         $result .= '<font color="#FF0000">There are no files available to select in this directory. Please go back and select another option.</font><br /><br />';
                   2098:     }
                   2099: 
                   2100:     $result .= $buttons;
                   2101: 
                   2102:     return $result;
1.20      bowersj2 2103: }
                   2104: 
                   2105: # Determine the state of the file: Published, unpublished, modified.
                   2106: # Return the color it should be in and a label as a two-element array
                   2107: # reference.
                   2108: # Logic lifted from lonpubdir.pm, even though I don't know that it's still
                   2109: # the most right thing to do.
                   2110: 
                   2111: sub fileState {
                   2112:     my $constructionSpaceDir = shift;
                   2113:     my $file = shift;
                   2114:     
                   2115:     my $docroot = $Apache::lonnet::perlvar{'lonDocRoot'};
                   2116:     my $subdirpart = $constructionSpaceDir;
                   2117:     $subdirpart =~ s/^\/home\/$ENV{'user.name'}\/public_html//;
                   2118:     my $resdir = $docroot . '/res/' . $ENV{'user.domain'} . '/' . $ENV{'user.name'} .
                   2119:         $subdirpart;
                   2120: 
                   2121:     my @constructionSpaceFileStat = stat($constructionSpaceDir . '/' . $file);
                   2122:     my @resourceSpaceFileStat = stat($resdir . '/' . $file);
                   2123:     if (!@resourceSpaceFileStat) {
                   2124:         return ['Unpublished', '#FFCCCC'];
                   2125:     }
                   2126: 
                   2127:     my $constructionSpaceFileModified = $constructionSpaceFileStat[9];
                   2128:     my $resourceSpaceFileModified = $resourceSpaceFileStat[9];
                   2129:     
                   2130:     if ($constructionSpaceFileModified > $resourceSpaceFileModified) {
                   2131:         return ['Modified', '#FFFFCC'];
                   2132:     }
                   2133:     return ['Published', '#CCFFCC'];
1.4       bowersj2 2134: }
1.5       bowersj2 2135: 
1.4       bowersj2 2136: sub postprocess {
                   2137:     my $self = shift;
1.6       bowersj2 2138:     my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
                   2139:     if (!$result) {
                   2140:         $self->{ERROR_MSG} = 'You must choose at least one file '.
                   2141:             'to continue.';
                   2142:         return 0;
                   2143:     }
                   2144: 
1.5       bowersj2 2145:     if ($self->{'multichoice'}) {
                   2146:         $self->process_multiple_choices($self->{'variable'}.'.forminput',
                   2147:                                         $self->{'variable'});
                   2148:     }
                   2149:     if (defined($self->{NEXTSTATE})) {
                   2150:         $helper->changeState($self->{NEXTSTATE});
1.3       bowersj2 2151:     }
1.6       bowersj2 2152: 
                   2153:     return 1;
1.3       bowersj2 2154: }
1.8       bowersj2 2155: 
                   2156: 1;
                   2157: 
1.11      bowersj2 2158: package Apache::lonhelper::section;
                   2159: 
                   2160: =pod
                   2161: 
                   2162: =head2 Element: section
                   2163: 
                   2164: <section> allows the user to choose one or more sections from the current
                   2165: course.
                   2166: 
                   2167: It takes the standard attributes "variable", "multichoice", and
                   2168: "nextstate", meaning what they do for most other elements.
                   2169: 
                   2170: =cut
                   2171: 
                   2172: no strict;
                   2173: @ISA = ("Apache::lonhelper::choices");
                   2174: use strict;
                   2175: 
                   2176: BEGIN {
                   2177:     &Apache::lonhelper::register('Apache::lonhelper::section',
                   2178:                                  ('section'));
                   2179: }
                   2180: 
                   2181: sub new {
                   2182:     my $ref = Apache::lonhelper::choices->new();
                   2183:     bless($ref);
                   2184: }
                   2185: 
                   2186: sub start_section {
                   2187:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   2188: 
                   2189:     if ($target ne 'helper') {
                   2190:         return '';
                   2191:     }
1.12      bowersj2 2192: 
                   2193:     $paramHash->{CHOICES} = [];
                   2194: 
1.11      bowersj2 2195:     $paramHash->{'variable'} = $token->[2]{'variable'};
                   2196:     $helper->declareVar($paramHash->{'variable'});
                   2197:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
                   2198:     if (defined($token->[2]{'nextstate'})) {
1.12      bowersj2 2199:         $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
1.11      bowersj2 2200:     }
                   2201: 
                   2202:     # Populate the CHOICES element
                   2203:     my %choices;
                   2204: 
                   2205:     my $section = Apache::loncoursedata::CL_SECTION();
                   2206:     my $classlist = Apache::loncoursedata::get_classlist();
                   2207:     foreach (keys %$classlist) {
                   2208:         my $sectionName = $classlist->{$_}->[$section];
                   2209:         if (!$sectionName) {
                   2210:             $choices{"No section assigned"} = "";
                   2211:         } else {
                   2212:             $choices{$sectionName} = $sectionName;
                   2213:         }
1.12      bowersj2 2214:     } 
                   2215:    
1.11      bowersj2 2216:     for my $sectionName (sort(keys(%choices))) {
1.12      bowersj2 2217:         
1.11      bowersj2 2218:         push @{$paramHash->{CHOICES}}, [$sectionName, $sectionName];
                   2219:     }
                   2220: }    
                   2221: 
1.12      bowersj2 2222: sub end_section {
                   2223:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1.11      bowersj2 2224: 
1.12      bowersj2 2225:     if ($target ne 'helper') {
                   2226:         return '';
                   2227:     }
                   2228:     Apache::lonhelper::section->new();
                   2229: }    
1.11      bowersj2 2230: 1;
                   2231: 
1.8       bowersj2 2232: package Apache::lonhelper::general;
                   2233: 
                   2234: =pod
                   2235: 
                   2236: =head2 General-purpose tag: <exec>
                   2237: 
                   2238: The contents of the exec tag are executed as Perl code, not inside a 
                   2239: safe space, so the full range of $ENV and such is available. The code
                   2240: will be executed as a subroutine wrapped with the following code:
                   2241: 
                   2242: "sub { my $helper = shift; my $state = shift;" and
                   2243: 
                   2244: "}"
                   2245: 
                   2246: The return value is ignored.
                   2247: 
                   2248: $helper is the helper object. Feel free to add methods to the helper
                   2249: object to support whatever manipulation you may need to do (for instance,
                   2250: overriding the form location if the state is the final state; see 
                   2251: lonparm.helper for an example).
                   2252: 
                   2253: $state is the $paramHash that has currently been generated and may
                   2254: be manipulated by the code in exec. Note that the $state is not yet
                   2255: an actual state B<object>, it is just a hash, so do not expect to
                   2256: be able to call methods on it.
                   2257: 
                   2258: =cut
                   2259: 
                   2260: BEGIN {
                   2261:     &Apache::lonhelper::register('Apache::lonhelper::general',
1.11      bowersj2 2262:                                  'exec', 'condition', 'clause',
                   2263:                                  'eval');
1.8       bowersj2 2264: }
                   2265: 
                   2266: sub start_exec {
                   2267:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   2268: 
                   2269:     if ($target ne 'helper') {
                   2270:         return '';
                   2271:     }
                   2272:     
                   2273:     my $code = &Apache::lonxml::get_all_text('/exec', $parser);
                   2274:     
                   2275:     $code = eval ('sub { my $helper = shift; my $state = shift; ' .
                   2276:         $code . "}");
1.11      bowersj2 2277:     die 'Error in <exec>, Perl said: '. $@ if $@;
1.8       bowersj2 2278:     &$code($helper, $paramHash);
                   2279: }
                   2280: 
                   2281: sub end_exec { return ''; }
                   2282: 
                   2283: =pod
                   2284: 
                   2285: =head2 General-purpose tag: <condition>
                   2286: 
                   2287: The <condition> tag allows you to mask out parts of the helper code
                   2288: depending on some programatically determined condition. The condition
                   2289: tag contains a tag <clause> which contains perl code that when wrapped
                   2290: with "sub { my $helper = shift; my $state = shift; " and "}", returns
                   2291: a true value if the XML in the condition should be evaluated as a normal
                   2292: part of the helper, or false if it should be completely discarded.
                   2293: 
                   2294: The <clause> tag must be the first sub-tag of the <condition> tag or
                   2295: it will not work as expected.
                   2296: 
                   2297: =cut
                   2298: 
                   2299: # The condition tag just functions as a marker, it doesn't have
                   2300: # to "do" anything. Technically it doesn't even have to be registered
                   2301: # with the lonxml code, but I leave this here to be explicit about it.
                   2302: sub start_condition { return ''; }
                   2303: sub end_condition { return ''; }
                   2304: 
                   2305: sub start_clause {
                   2306:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   2307: 
                   2308:     if ($target ne 'helper') {
                   2309:         return '';
                   2310:     }
                   2311:     
                   2312:     my $clause = Apache::lonxml::get_all_text('/clause', $parser);
                   2313:     $clause = eval('sub { my $helper = shift; my $state = shift; '
                   2314:         . $clause . '}');
1.11      bowersj2 2315:     die 'Error in clause of condition, Perl said: ' . $@ if $@;
1.8       bowersj2 2316:     if (!&$clause($helper, $paramHash)) {
                   2317:         # Discard all text until the /condition.
                   2318:         &Apache::lonxml::get_all_text('/condition', $parser);
                   2319:     }
                   2320: }
                   2321: 
                   2322: sub end_clause { return ''; }
1.11      bowersj2 2323: 
                   2324: =pod
                   2325: 
                   2326: =head2 General-purpose tag: <eval>
                   2327: 
                   2328: The <eval> tag will be evaluated as a subroutine call passed in the
                   2329: current helper object and state hash as described in <condition> above,
                   2330: but is expected to return a string to be printed directly to the
                   2331: screen. This is useful for dynamically generating messages. 
                   2332: 
                   2333: =cut
                   2334: 
                   2335: # This is basically a type of message.
                   2336: # Programmatically setting $paramHash->{NEXTSTATE} would work, though
                   2337: # it's probably bad form.
                   2338: 
                   2339: sub start_eval {
                   2340:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   2341: 
                   2342:     if ($target ne 'helper') {
                   2343:         return '';
                   2344:     }
                   2345:     
                   2346:     my $program = Apache::lonxml::get_all_text('/eval', $parser);
                   2347:     $program = eval('sub { my $helper = shift; my $state = shift; '
                   2348:         . $program . '}');
                   2349:     die 'Error in eval code, Perl said: ' . $@ if $@;
                   2350:     $paramHash->{MESSAGE_TEXT} = &$program($helper, $paramHash);
                   2351: }
                   2352: 
                   2353: sub end_eval { 
                   2354:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   2355: 
                   2356:     if ($target ne 'helper') {
                   2357:         return '';
                   2358:     }
                   2359: 
                   2360:     Apache::lonhelper::message->new();
                   2361: }
                   2362: 
1.13      bowersj2 2363: 1;
                   2364: 
                   2365: package Apache::lonhelper::parmwizfinal;
                   2366: 
                   2367: # This is the final state for the parmwizard. It is not generally useful,
                   2368: # so it is not perldoc'ed. It does its own processing.
                   2369: # It is represented with <parmwizfinal />, and
                   2370: # should later be moved to lonparmset.pm .
                   2371: 
                   2372: no strict;
                   2373: @ISA = ('Apache::lonhelper::element');
                   2374: use strict;
1.11      bowersj2 2375: 
1.13      bowersj2 2376: BEGIN {
                   2377:     &Apache::lonhelper::register('Apache::lonhelper::parmwizfinal',
                   2378:                                  ('parmwizfinal'));
                   2379: }
                   2380: 
                   2381: use Time::localtime;
                   2382: 
                   2383: sub new {
                   2384:     my $ref = Apache::lonhelper::choices->new();
                   2385:     bless ($ref);
                   2386: }
                   2387: 
                   2388: sub start_parmwizfinal { return ''; }
                   2389: 
                   2390: sub end_parmwizfinal {
                   2391:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
                   2392: 
                   2393:     if ($target ne 'helper') {
                   2394:         return '';
                   2395:     }
                   2396:     Apache::lonhelper::parmwizfinal->new();
                   2397: }
                   2398: 
                   2399: # Renders a form that, when submitted, will form the input to lonparmset.pm
                   2400: sub render {
                   2401:     my $self = shift;
                   2402:     my $vars = $helper->{VARS};
                   2403: 
                   2404:     # FIXME: Unify my designators with the standard ones
                   2405:     my %dateTypeHash = ('open_date' => "Opening Date",
                   2406:                         'due_date' => "Due Date",
                   2407:                         'answer_date' => "Answer Date");
                   2408:     my %parmTypeHash = ('open_date' => "0_opendate",
                   2409:                         'due_date' => "0_duedate",
                   2410:                         'answer_date' => "0_answerdate");
                   2411:     
1.14      bowersj2 2412:     my $result = "<form name='helpform' method='get' action='/adm/parmset'>\n";
1.13      bowersj2 2413:     $result .= '<p>Confirm that this information is correct, then click &quot;Finish Wizard&quot; to complete setting the parameter.<ul>';
                   2414:     my $affectedResourceId = "";
                   2415:     my $parm_name = $parmTypeHash{$vars->{ACTION_TYPE}};
                   2416:     my $level = "";
                   2417:     
                   2418:     # Print the type of manipulation:
                   2419:     $result .= '<li>Setting the <b>' . $dateTypeHash{$vars->{ACTION_TYPE}}
                   2420:                . "</b></li>\n";
                   2421:     if ($vars->{ACTION_TYPE} eq 'due_date' || 
                   2422:         $vars->{ACTION_TYPE} eq 'answer_date') {
                   2423:         # for due dates, we default to "date end" type entries
                   2424:         $result .= "<input type='hidden' name='recent_date_end' " .
                   2425:             "value='" . $vars->{PARM_DATE} . "' />\n";
                   2426:         $result .= "<input type='hidden' name='pres_value' " . 
                   2427:             "value='" . $vars->{PARM_DATE} . "' />\n";
                   2428:         $result .= "<input type='hidden' name='pres_type' " .
                   2429:             "value='date_end' />\n";
                   2430:     } elsif ($vars->{ACTION_TYPE} eq 'open_date') {
                   2431:         $result .= "<input type='hidden' name='recent_date_start' ".
                   2432:             "value='" . $vars->{PARM_DATE} . "' />\n";
                   2433:         $result .= "<input type='hidden' name='pres_value' " .
                   2434:             "value='" . $vars->{PARM_DATE} . "' />\n";
                   2435:         $result .= "<input type='hidden' name='pres_type' " .
                   2436:             "value='date_start' />\n";
                   2437:     } 
                   2438:     
                   2439:     # Print the granularity, depending on the action
                   2440:     if ($vars->{GRANULARITY} eq 'whole_course') {
                   2441:         $result .= '<li>for <b>all resources in the course</b></li>';
                   2442:         $level = 9; # general course, see lonparmset.pm perldoc
                   2443:         $affectedResourceId = "0.0";
                   2444:     } elsif ($vars->{GRANULARITY} eq 'map') {
                   2445:         my $navmap = Apache::lonnavmaps::navmap->new(
                   2446:                            $ENV{"request.course.fn"}.".db",
                   2447:                            $ENV{"request.course.fn"}."_parms.db", 0, 0);
                   2448:         my $res = $navmap->getById($vars->{RESOURCE_ID});
                   2449:         my $title = $res->compTitle();
                   2450:         $navmap->untieHashes();
                   2451:         $result .= "<li>for the map named <b>$title</b></li>";
                   2452:         $level = 8;
                   2453:         $affectedResourceId = $vars->{RESOURCE_ID};
                   2454:     } else {
                   2455:         my $navmap = Apache::lonnavmaps::navmap->new(
                   2456:                            $ENV{"request.course.fn"}.".db",
                   2457:                            $ENV{"request.course.fn"}."_parms.db", 0, 0);
                   2458:         my $res = $navmap->getById($vars->{RESOURCE_ID});
                   2459:         my $title = $res->compTitle();
                   2460:         $navmap->untieHashes();
                   2461:         $result .= "<li>for the resource named <b>$title</b></li>";
                   2462:         $level = 7;
                   2463:         $affectedResourceId = $vars->{RESOURCE_ID};
                   2464:     }
                   2465: 
                   2466:     # Print targets
                   2467:     if ($vars->{TARGETS} eq 'course') {
                   2468:         $result .= '<li>for <b>all students in course</b></li>';
                   2469:     } elsif ($vars->{TARGETS} eq 'section') {
                   2470:         my $section = $vars->{SECTION_NAME};
                   2471:         $result .= "<li>for section <b>$section</b></li>";
                   2472:         $level -= 3;
                   2473:         $result .= "<input type='hidden' name='csec' value='" .
                   2474:             HTML::Entities::encode($section) . "' />\n";
                   2475:     } else {
                   2476:         # FIXME: This is probably wasteful! Store the name!
                   2477:         my $classlist = Apache::loncoursedata::get_classlist();
                   2478:         my $name = $classlist->{$vars->{USER_NAME}}->[6];
                   2479:         $result .= "<li>for <b>$name</b></li>";
                   2480:         $level -= 6;
                   2481:         my ($uname, $udom) = split /:/, $vars->{USER_NAME};
                   2482:         $result .= "<input type='hidden' name='uname' value='".
                   2483:             HTML::Entities::encode($uname) . "' />\n";
                   2484:         $result .= "<input type='hidden' name='udom' value='".
                   2485:             HTML::Entities::encode($udom) . "' />\n";
                   2486:     }
                   2487: 
                   2488:     # Print value
                   2489:     $result .= "<li>to <b>" . ctime($vars->{PARM_DATE}) . "</b> (" .
                   2490:         Apache::lonnavmaps::timeToHumanString($vars->{PARM_DATE}) 
                   2491:         . ")</li>\n";
                   2492: 
                   2493:     # print pres_marker
                   2494:     $result .= "\n<input type='hidden' name='pres_marker'" .
                   2495:         " value='$affectedResourceId&$parm_name&$level' />\n";
                   2496: 
                   2497:     $result .= "<br /><br /><center><input type='submit' value='Finish Helper' /></center></form>\n";
                   2498: 
                   2499:     return $result;
                   2500: }
                   2501:     
                   2502: sub overrideForm {
                   2503:     return 1;
                   2504: }
1.5       bowersj2 2505: 
1.4       bowersj2 2506: 1;
1.3       bowersj2 2507: 
1.1       bowersj2 2508: __END__
1.3       bowersj2 2509: 

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>