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Allow specification of required priviledges to use a helper.

    1: # The LearningOnline Network with CAPA
    2: # .helper XML handler to implement the LON-CAPA helper
    3: #
    4: # $Id: lonhelper.pm,v 1.31 2003/05/16 17:20:51 bowersj2 Exp $
    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: 
   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". The helper tag may optionally
   57: have a "requiredpriv" attribute, specifying the priviledge a user must have
   58: to use the helper, or get denied access. See loncom/auth/rolesplain.tab for
   59: useful privs. Default is full access, which is often wrong!
   60: 
   61: =head2 State tags
   62: 
   63: State tags are required to have an attribute "name", which is the symbolic
   64: name of the state and will not be directly seen by the user. The helper is
   65: required to have one state named "START", which is the state the helper
   66: will start with. By convention, this state should clearly describe what
   67: the helper will do for the user, and may also include the first information
   68: entry the user needs to do for the helper.
   69: 
   70: State tags are also required to have an attribute "title", which is the
   71: human name of the state, and will be displayed as the header on top of 
   72: the screen for the user.
   73: 
   74: =head2 Example Helper Skeleton
   75: 
   76: An example of the tags so far:
   77: 
   78:  <helper title="Example Helper">
   79:    <state name="START" title="Demonstrating the Example Helper">
   80:      <!-- notice this is the START state the wizard requires -->
   81:      </state>
   82:    <state name="GET_NAME" title="Enter Student Name">
   83:      </state>
   84:    </helper>
   85: 
   86: Of course this does nothing. In order for the wizard to do something, it is
   87: necessary to put actual elements into the wizard. Documentation for each
   88: of these elements follows.
   89: 
   90: =head2 Creating a Helper With Code, Not XML
   91: 
   92: In some situations, such as the printing wizard (see lonprintout.pm), 
   93: writing the helper in XML would be too complicated, because of scope 
   94: issues or the fact that the code actually outweighs the XML. It is
   95: possible to create a helper via code, though it is a little odd.
   96: 
   97: Creating a helper via code is more like issuing commands to create
   98: a helper then normal code writing. For instance, elements will automatically
   99: be added to the last state created, so it's important to create the 
  100: states in the correct order.
  101: 
  102: First, create a new helper:
  103: 
  104:  use Apache::lonhelper;
  105: 
  106:  my $helper = Apache::lonhelper::new->("Helper Title");
  107: 
  108: Next you'll need to manually add states to the helper:
  109: 
  110:  Apache::lonhelper::state->new("STATE_NAME", "State's Human Title");
  111: 
  112: You don't need to save a reference to it because all elements up until
  113: the next state creation will automatically be added to this state.
  114: 
  115: Elements are created by populating the $paramHash in 
  116: Apache::lonhelper::paramhash. To prevent namespace issues, retrieve 
  117: a reference to that has with getParamHash:
  118: 
  119:  my $paramHash = Apache::lonhelper::getParamHash();
  120: 
  121: You will need to do this for each state you create.
  122: 
  123: Populate the $paramHash with the parameters for the element you wish
  124: to add next; the easiest way to find out what those entries are is
  125: to read the code. Some common ones are 'variable' to record the variable
  126: to store the results in, and NEXTSTATE to record a next state transition.
  127: 
  128: Then create your element:
  129: 
  130:  $paramHash->{MESSAGETEXT} = "This is a message.";
  131:  Apache::lonhelper::message->new();
  132: 
  133: The creation will take the $paramHash and bless it into a
  134: Apache::lonhelper::message object. To create the next element, you need
  135: to get a reference to the new, empty $paramHash:
  136: 
  137:  $paramHash = Apache::lonhelper::getParamHash();
  138: 
  139: and you can repeat creating elements that way. You can add states
  140: and elements as needed.
  141: 
  142: See lonprintout.pm, subroutine printHelper for an example of this, where
  143: we dynamically add some states to prevent security problems, for instance.
  144: 
  145: Normally the machinery in the XML format is sufficient; dynamically 
  146: adding states can easily be done by wrapping the state in a <condition>
  147: tag. This should only be used when the code dominates the XML content,
  148: the code is so complicated that it is difficult to get access to
  149: all of the information you need because of scoping issues, or so much
  150: of the information used is persistent because would-be <exec> or 
  151: <eval> blocks that using the {DATA} mechanism results in hard-to-read
  152: and -maintain code.
  153: 
  154: It is possible to do some of the work with an XML fragment parsed by
  155: lonxml; again, see lonprintout.pm for an example. In that case it is 
  156: imperative that you call B<Apache::lonhelper::registerHelperTags()>
  157: before parsing XML fragments and B<Apache::lonhelper::unregisterHelperTags()>
  158: when you are done. See lonprintout.pm for examples of this usage in the
  159: printHelper subroutine.
  160: 
  161: =cut
  162: 
  163: package Apache::lonhelper;
  164: use Apache::Constants qw(:common);
  165: use Apache::File;
  166: use Apache::lonxml;
  167: 
  168: # Register all the tags with the helper, so the helper can 
  169: # push and pop them
  170: 
  171: my @helperTags;
  172: 
  173: sub register {
  174:     my ($namespace, @tags) = @_;
  175: 
  176:     for my $tag (@tags) {
  177:         push @helperTags, [$namespace, $tag];
  178:     }
  179: }
  180: 
  181: BEGIN {
  182:     Apache::lonxml::register('Apache::lonhelper', 
  183:                              ('helper'));
  184:       register('Apache::lonhelper', ('state'));
  185: }
  186: 
  187: # Since all helpers are only three levels deep (helper tag, state tag, 
  188: # substate type), it's easier and more readble to explicitly track 
  189: # those three things directly, rather then futz with the tag stack 
  190: # every time.
  191: my $helper;
  192: my $state;
  193: my $substate;
  194: # To collect parameters, the contents of the subtags are collected
  195: # into this paramHash, then passed to the element object when the 
  196: # end of the element tag is located.
  197: my $paramHash; 
  198: 
  199: # Note from Jeremy 5-8-2003: It is *vital* that the real handler be called
  200: # as a subroutine from the handler, or very mysterious things might happen.
  201: # I don't know exactly why, but it seems that the scope where the Apache
  202: # server enters the perl handler is treated differently from the rest of
  203: # the handler. This also seems to manifest itself in the debugger as entering
  204: # the perl handler in seemingly random places (sometimes it starts in the
  205: # compiling phase, sometimes in the handler execution phase where it runs
  206: # the code and stepping into the "1;" the module ends with goes into the handler,
  207: # sometimes starting directly with the handler); I think the cause is related.
  208: # In the debugger, this means that breakpoints are ignored until you step into
  209: # a function and get out of what must be a "faked up scope" in the Apache->
  210: # mod_perl connection. In this code, it was manifesting itself in the existence
  211: # of two seperate file-scoped $helper variables, one set to the value of the
  212: # helper in the helper constructor, and one referenced by the handler on the
  213: # "$helper->process()" line. The second was therefore never set, and was still
  214: # undefined when I tried to call process on it.
  215: # By pushing the "real handler" down into the "real scope", everybody except the 
  216: # actual handler function directly below this comment gets the same $helper and
  217: # everybody is happy.
  218: # The upshot of all of this is that for safety when a handler is  using 
  219: # file-scoped variables in LON-CAPA, the handler should be pushed down one 
  220: # call level, as I do here, to ensure that the top-level handler function does
  221: # not get a different file scope from the rest of the code.
  222: sub handler {
  223:     my $r = shift;
  224:     return real_handler($r);
  225: }
  226: 
  227: # For debugging purposes, one can send a second parameter into this
  228: # function, the 'uri' of the helper you wish to have rendered, and
  229: # call this from other handlers.
  230: sub real_handler {
  231:     my $r = shift;
  232:     my $uri = shift;
  233:     if (!defined($uri)) { $uri = $r->uri(); }
  234:     $ENV{'request.uri'} = $uri;
  235:     my $filename = '/home/httpd/html' . $uri;
  236:     my $fh = Apache::File->new($filename);
  237:     my $file;
  238:     read $fh, $file, 100000000;
  239: 
  240: 
  241:     # Send header, don't cache this page
  242:     if ($r->header_only) {
  243:         if ($ENV{'browser.mathml'}) {
  244:             $r->content_type('text/xml');
  245:         } else {
  246:             $r->content_type('text/html');
  247:         }
  248:         $r->send_http_header;
  249:         return OK;
  250:     }
  251:     if ($ENV{'browser.mathml'}) {
  252:         $r->content_type('text/xml');
  253:     } else {
  254:         $r->content_type('text/html');
  255:     }
  256:     $r->send_http_header;
  257:     $r->rflush();
  258: 
  259:     # Discard result, we just want the objects that get created by the
  260:     # xml parsing
  261:     &Apache::lonxml::xmlparse($r, 'helper', $file);
  262: 
  263:     my $allowed = $helper->allowedCheck();
  264:     if (!$allowed) {
  265:         $ENV{'user.error.msg'} = $ENV{'request.uri'}.':'.$helper->{REQUIRED_PRIV}.
  266:             ":0:0:Permission denied to access this helper.";
  267:         return HTTP_NOT_ACCEPTABLE;
  268:     }
  269: 
  270:     $helper->process();
  271: 
  272:     $r->print($helper->display());
  273:     return OK;
  274: }
  275: 
  276: sub registerHelperTags {
  277:     for my $tagList (@helperTags) {
  278:         Apache::lonxml::register($tagList->[0], $tagList->[1]);
  279:     }
  280: }
  281: 
  282: sub unregisterHelperTags {
  283:     for my $tagList (@helperTags) {
  284:         Apache::lonxml::deregister($tagList->[0], $tagList->[1]);
  285:     }
  286: }
  287: 
  288: sub start_helper {
  289:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  290: 
  291:     if ($target ne 'helper') {
  292:         return '';
  293:     }
  294: 
  295:     registerHelperTags();
  296: 
  297:     Apache::lonhelper::helper->new($token->[2]{'title'}, $token->[2]{'requiredpriv'});
  298:     return '';
  299: }
  300: 
  301: sub end_helper {
  302:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  303:     
  304:     if ($target ne 'helper') {
  305:         return '';
  306:     }
  307: 
  308:     unregisterHelperTags();
  309: 
  310:     return '';
  311: }
  312: 
  313: sub start_state {
  314:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  315: 
  316:     if ($target ne 'helper') {
  317:         return '';
  318:     }
  319: 
  320:     Apache::lonhelper::state->new($token->[2]{'name'},
  321:                                   $token->[2]{'title'});
  322:     return '';
  323: }
  324: 
  325: # Use this to get the param hash from other files.
  326: sub getParamHash {
  327:     return $paramHash;
  328: }
  329: 
  330: # Use this to get the helper, if implementing elements in other files
  331: # (like lonprintout.pm)
  332: sub getHelper {
  333:     return $helper;
  334: }
  335: 
  336: # don't need this, so ignore it
  337: sub end_state {
  338:     return '';
  339: }
  340: 
  341: 1;
  342: 
  343: package Apache::lonhelper::helper;
  344: 
  345: use Digest::MD5 qw(md5_hex);
  346: use HTML::Entities;
  347: use Apache::loncommon;
  348: use Apache::File;
  349: 
  350: sub new {
  351:     my $proto = shift;
  352:     my $class = ref($proto) || $proto;
  353:     my $self = {};
  354: 
  355:     $self->{TITLE} = shift;
  356:     $self->{REQUIRED_PRIV} = shift;
  357:     
  358:     # If there is a state from the previous form, use that. If there is no
  359:     # state, use the start state parameter.
  360:     if (defined $ENV{"form.CURRENT_STATE"})
  361:     {
  362: 	$self->{STATE} = $ENV{"form.CURRENT_STATE"};
  363:     }
  364:     else
  365:     {
  366: 	$self->{STATE} = "START";
  367:     }
  368: 
  369:     $self->{TOKEN} = $ENV{'form.TOKEN'};
  370:     # If a token was passed, we load that in. Otherwise, we need to create a 
  371:     # new storage file
  372:     # Tried to use standard Tie'd hashes, but you can't seem to take a 
  373:     # reference to a tied hash and write to it. I'd call that a wart.
  374:     if ($self->{TOKEN}) {
  375:         # Validate the token before trusting it
  376:         if ($self->{TOKEN} !~ /^[a-f0-9]{32}$/) {
  377:             # Not legit. Return nothing and let all hell break loose.
  378:             # User shouldn't be doing that!
  379:             return undef;
  380:         }
  381: 
  382:         # Get the hash.
  383:         $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN}); # Note the token is not the literal file
  384:         
  385:         my $file = Apache::File->new($self->{FILENAME});
  386:         my $contents = <$file>;
  387: 
  388:         # Now load in the contents
  389:         for my $value (split (/&/, $contents)) {
  390:             my ($name, $value) = split(/=/, $value);
  391:             $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
  392:             $self->{VARS}->{$name} = $value;
  393:         }
  394: 
  395:         $file->close();
  396:     } else {
  397:         # Only valid if we're just starting.
  398:         if ($self->{STATE} ne 'START') {
  399:             return undef;
  400:         }
  401:         # Must create the storage
  402:         $self->{TOKEN} = md5_hex($ENV{'user.name'} . $ENV{'user.domain'} .
  403:                                  time() . rand());
  404:         $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN});
  405:     }
  406: 
  407:     # OK, we now have our persistent storage.
  408: 
  409:     if (defined $ENV{"form.RETURN_PAGE"})
  410:     {
  411: 	$self->{RETURN_PAGE} = $ENV{"form.RETURN_PAGE"};
  412:     }
  413:     else
  414:     {
  415: 	$self->{RETURN_PAGE} = $ENV{REFERER};
  416:     }
  417: 
  418:     $self->{STATES} = {};
  419:     $self->{DONE} = 0;
  420: 
  421:     # Used by various helpers for various things; see lonparm.helper
  422:     # for an example.
  423:     $self->{DATA} = {};
  424: 
  425:     $helper = $self;
  426: 
  427:     # Establish the $paramHash
  428:     $paramHash = {};
  429: 
  430:     bless($self, $class);
  431:     return $self;
  432: }
  433: 
  434: # Private function; returns a string to construct the hidden fields
  435: # necessary to have the helper track state.
  436: sub _saveVars {
  437:     my $self = shift;
  438:     my $result = "";
  439:     $result .= '<input type="hidden" name="CURRENT_STATE" value="' .
  440:         HTML::Entities::encode($self->{STATE}) . "\" />\n";
  441:     $result .= '<input type="hidden" name="TOKEN" value="' .
  442:         $self->{TOKEN} . "\" />\n";
  443:     $result .= '<input type="hidden" name="RETURN_PAGE" value="' .
  444:         HTML::Entities::encode($self->{RETURN_PAGE}) . "\" />\n";
  445: 
  446:     return $result;
  447: }
  448: 
  449: # Private function: Create the querystring-like representation of the stored
  450: # data to write to disk.
  451: sub _varsInFile {
  452:     my $self = shift;
  453:     my @vars = ();
  454:     for my $key (keys %{$self->{VARS}}) {
  455:         push @vars, &Apache::lonnet::escape($key) . '=' .
  456:             &Apache::lonnet::escape($self->{VARS}->{$key});
  457:     }
  458:     return join ('&', @vars);
  459: }
  460: 
  461: # Use this to declare variables.
  462: # FIXME: Document this
  463: sub declareVar {
  464:     my $self = shift;
  465:     my $var = shift;
  466: 
  467:     if (!defined($self->{VARS}->{$var})) {
  468:         $self->{VARS}->{$var} = '';
  469:     }
  470: 
  471:     my $envname = 'form.' . $var . '.forminput';
  472:     if (defined($ENV{$envname})) {
  473:         if (ref($ENV{$envname})) {
  474:             $self->{VARS}->{$var} = join('|||', @{$ENV{$envname}});
  475:         } else {
  476:             $self->{VARS}->{$var} = $ENV{$envname};
  477:         }
  478:     }
  479: }
  480: 
  481: sub allowedCheck {
  482:     my $self = shift;
  483: 
  484:     if (!defined($self->{REQUIRED_PRIV})) { 
  485:         return 1;
  486:     }
  487: 
  488:     return Apache::lonnet::allowed($self->{REQUIRED_PRIV}, $ENV{'request.course.id'});
  489: }
  490: 
  491: sub changeState {
  492:     my $self = shift;
  493:     $self->{STATE} = shift;
  494: }
  495: 
  496: sub registerState {
  497:     my $self = shift;
  498:     my $state = shift;
  499: 
  500:     my $stateName = $state->name();
  501:     $self->{STATES}{$stateName} = $state;
  502: }
  503: 
  504: sub process {
  505:     my $self = shift;
  506: 
  507:     # Phase 1: Post processing for state of previous screen (which is actually
  508:     # the "current state" in terms of the helper variables), if it wasn't the 
  509:     # beginning state.
  510:     if ($self->{STATE} ne "START" || $ENV{"form.SUBMIT"} eq "Next ->") {
  511: 	my $prevState = $self->{STATES}{$self->{STATE}};
  512:         $prevState->postprocess();
  513:     }
  514:     
  515:     # Note, to handle errors in a state's input that a user must correct,
  516:     # do not transition in the postprocess, and force the user to correct
  517:     # the error.
  518: 
  519:     # Phase 2: Preprocess current state
  520:     my $startState = $self->{STATE};
  521:     my $state = $self->{STATES}->{$startState};
  522:     
  523:     # For debugging, print something here to determine if you're going
  524:     # to an undefined state.
  525:     if (!defined($state)) {
  526:         return;
  527:     }
  528:     $state->preprocess();
  529: 
  530:     # Phase 3: While the current state is different from the previous state,
  531:     # keep processing.
  532:     while ( $startState ne $self->{STATE} && 
  533:             defined($self->{STATES}->{$self->{STATE}}) )
  534:     {
  535: 	$startState = $self->{STATE};
  536: 	$state = $self->{STATES}->{$startState};
  537: 	$state->preprocess();
  538:     }
  539: 
  540:     return;
  541: } 
  542: 
  543: # 1: Do the post processing for the previous state.
  544: # 2: Do the preprocessing for the current state.
  545: # 3: Check to see if state changed, if so, postprocess current and move to next.
  546: #    Repeat until state stays stable.
  547: # 4: Render the current state to the screen as an HTML page.
  548: sub display {
  549:     my $self = shift;
  550: 
  551:     my $state = $self->{STATES}{$self->{STATE}};
  552: 
  553:     my $result = "";
  554: 
  555:     if (!defined($state)) {
  556:         $result = "<font color='#ff0000'>Error: state '$state' not defined!</font>";
  557:         return $result;
  558:     }
  559: 
  560:     # Phase 4: Display.
  561:     my $stateTitle = $state->title();
  562:     my $bodytag = &Apache::loncommon::bodytag("$self->{TITLE}",'','');
  563: 
  564:     $result .= <<HEADER;
  565: <html>
  566:     <head>
  567:         <title>LON-CAPA Helper: $self->{TITLE}</title>
  568:     </head>
  569:     $bodytag
  570: HEADER
  571:     if (!$state->overrideForm()) { $result.="<form name='helpform' method='POST'>"; }
  572:     $result .= <<HEADER;
  573:         <table border="0" width='100%'><tr><td>
  574:         <h2><i>$stateTitle</i></h2>
  575: HEADER
  576: 
  577:     $result .= "<table cellpadding='10' width='100%'><tr><td rowspan='2' valign='top'>";
  578: 
  579:     if (!$state->overrideForm()) {
  580:         $result .= $self->_saveVars();
  581:     }
  582:     $result .= $state->render();
  583: 
  584:     $result .= "</td><td valign='top' align='right'>";
  585: 
  586:     # Warning: Copy and pasted from below, because it's too much trouble to 
  587:     # turn this into a subroutine
  588:     if (!$state->overrideForm()) {
  589:         if ($self->{STATE} ne $self->{START_STATE}) {
  590:             #$result .= '<input name="SUBMIT" type="submit" value="&lt;- Previous" />&nbsp;&nbsp;';
  591:         }
  592:         if ($self->{DONE}) {
  593:             my $returnPage = $self->{RETURN_PAGE};
  594:             $result .= "<a href=\"$returnPage\">End Helper</a>";
  595:         }
  596:         else {
  597:             $result .= '<nobr><input name="back" type="button" ';
  598:             $result .= 'value="&lt;- Previous" onclick="history.go(-1)" /> ';
  599:             $result .= '<input name="SUBMIT" type="submit" value="Next -&gt;" /></nobr>';
  600:         }
  601:     }
  602: 
  603:     $result .= "</td></tr><tr><td valign='bottom' align='right'>";
  604: 
  605:     # Warning: Copy and pasted from above, because it's too much trouble to 
  606:     # turn this into a subroutine
  607:     if (!$state->overrideForm()) {
  608:         if ($self->{STATE} ne $self->{START_STATE}) {
  609:             #$result .= '<input name="SUBMIT" type="submit" value="&lt;- Previous" />&nbsp;&nbsp;';
  610:         }
  611:         if ($self->{DONE}) {
  612:             my $returnPage = $self->{RETURN_PAGE};
  613:             $result .= "<a href=\"$returnPage\">End Helper</a>";
  614:         }
  615:         else {
  616:             $result .= '<nobr><input name="back" type="button" ';
  617:             $result .= 'value="&lt;- Previous" onclick="history.go(-1)" /> ';
  618:             $result .= '<input name="SUBMIT" type="submit" value="Next -&gt;" /></nobr>';
  619:         }
  620:     }
  621: 
  622:     #foreach my $key (keys %{$self->{VARS}}) {
  623:     #    $result .= "|$key| -> " . $self->{VARS}->{$key} . "<br />";
  624:     #}
  625: 
  626:     $result .= "</td></tr></table>";
  627: 
  628:     $result .= <<FOOTER;
  629:               </td>
  630:             </tr>
  631:           </table>
  632:         </form>
  633:     </body>
  634: </html>
  635: FOOTER
  636: 
  637:     # Handle writing out the vars to the file
  638:     my $file = Apache::File->new('>'.$self->{FILENAME});
  639:     print $file $self->_varsInFile();
  640: 
  641:     return $result;
  642: }
  643: 
  644: 1;
  645: 
  646: package Apache::lonhelper::state;
  647: 
  648: # States bundle things together and are responsible for compositing the
  649: # various elements together. It is not generally necessary for users to
  650: # use the state object directly, so it is not perldoc'ed.
  651: 
  652: # Basically, all the states do is pass calls to the elements and aggregate
  653: # the results.
  654: 
  655: sub new {
  656:     my $proto = shift;
  657:     my $class = ref($proto) || $proto;
  658:     my $self = {};
  659: 
  660:     $self->{NAME} = shift;
  661:     $self->{TITLE} = shift;
  662:     $self->{ELEMENTS} = [];
  663: 
  664:     bless($self, $class);
  665: 
  666:     $helper->registerState($self);
  667: 
  668:     $state = $self;
  669: 
  670:     return $self;
  671: }
  672: 
  673: sub name {
  674:     my $self = shift;
  675:     return $self->{NAME};
  676: }
  677: 
  678: sub title {
  679:     my $self = shift;
  680:     return $self->{TITLE};
  681: }
  682: 
  683: sub preprocess {
  684:     my $self = shift;
  685:     for my $element (@{$self->{ELEMENTS}}) {
  686:         $element->preprocess();
  687:     }
  688: }
  689: 
  690: # FIXME: Document that all postprocesses must return a true value or
  691: # the state transition will be overridden
  692: sub postprocess {
  693:     my $self = shift;
  694: 
  695:     # Save the state so we can roll it back if we need to.
  696:     my $originalState = $helper->{STATE};
  697:     my $everythingSuccessful = 1;
  698: 
  699:     for my $element (@{$self->{ELEMENTS}}) {
  700:         my $result = $element->postprocess();
  701:         if (!$result) { $everythingSuccessful = 0; }
  702:     }
  703: 
  704:     # If not all the postprocesses were successful, override
  705:     # any state transitions that may have occurred. It is the
  706:     # responsibility of the states to make sure they have 
  707:     # error handling in that case.
  708:     if (!$everythingSuccessful) {
  709:         $helper->{STATE} = $originalState;
  710:     }
  711: }
  712: 
  713: # Override the form if any element wants to.
  714: # two elements overriding the form will make a mess, but that should
  715: # be considered helper author error ;-)
  716: sub overrideForm {
  717:     my $self = shift;
  718:     for my $element (@{$self->{ELEMENTS}}) {
  719:         if ($element->overrideForm()) {
  720:             return 1;
  721:         }
  722:     }
  723:     return 0;
  724: }
  725: 
  726: sub addElement {
  727:     my $self = shift;
  728:     my $element = shift;
  729:     
  730:     push @{$self->{ELEMENTS}}, $element;
  731: }
  732: 
  733: sub render {
  734:     my $self = shift;
  735:     my @results = ();
  736: 
  737:     for my $element (@{$self->{ELEMENTS}}) {
  738:         push @results, $element->render();
  739:     }
  740: 
  741:     return join("\n", @results);
  742: }
  743: 
  744: 1;
  745: 
  746: package Apache::lonhelper::element;
  747: # Support code for elements
  748: 
  749: =pod
  750: 
  751: =head2 Element Base Class
  752: 
  753: The Apache::lonhelper::element base class provides support for elements
  754: and defines some generally useful tags for use in elements.
  755: 
  756: B<finalcode tag>
  757: 
  758: Each element can contain a "finalcode" tag that, when the special FINAL
  759: helper state is used, will be executed, surrounded by "sub { my $helper = shift;"
  760: and "}". It is expected to return a string describing what it did, which 
  761: may be an empty string. See course initialization helper for an example. This is
  762: generally intended for helpers like the course initialization helper, which consist
  763: of several panels, each of which is performing some sort of bite-sized functionality.
  764: 
  765: B<defaultvalue tag>
  766: 
  767: Each element that accepts user input can contain a "defaultvalue" tag that,
  768: when surrounded by "sub { my $helper = shift; my $state = shift; " and "}",
  769: will form a subroutine that when called will provide a default value for
  770: the element. How this value is interpreted by the element is specific to
  771: the element itself, and possibly the settings the element has (such as 
  772: multichoice vs. single choice for <choices> tags). 
  773: 
  774: This is also intended for things like the course initialization wizard, where the
  775: user is setting various parameters. By correctly grabbing current settings 
  776: and including them into the helper, it allows the user to come back to the
  777: helper later and re-execute it, without needing to worry about overwriting
  778: some setting accidentally.
  779: 
  780: Again, see the course initialization helper for examples.
  781: 
  782: B<getValue method>
  783: 
  784: If the element stores the name of the variable in a 'variable' member, which
  785: the provided ones all do, you can retreive the value of the variable by calling
  786: this method.
  787: 
  788: =cut
  789: 
  790: BEGIN {
  791:     &Apache::lonhelper::register('Apache::lonhelper::element',
  792:                                  ('nextstate', 'finalcode',
  793:                                   'defaultvalue'));
  794: }
  795: 
  796: # Because we use the param hash, this is often a sufficent
  797: # constructor
  798: sub new {
  799:     my $proto = shift;
  800:     my $class = ref($proto) || $proto;
  801:     my $self = $paramHash;
  802:     bless($self, $class);
  803: 
  804:     $self->{PARAMS} = $paramHash;
  805:     $self->{STATE} = $state;
  806:     $state->addElement($self);
  807:     
  808:     # Ensure param hash is not reused
  809:     $paramHash = {};
  810: 
  811:     return $self;
  812: }   
  813: 
  814: sub start_nextstate {
  815:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  816: 
  817:     if ($target ne 'helper') {
  818:         return '';
  819:     }
  820:     
  821:     $paramHash->{NEXTSTATE} = &Apache::lonxml::get_all_text('/nextstate',
  822:                                                              $parser);
  823:     return '';
  824: }
  825: 
  826: sub end_nextstate { return ''; }
  827: 
  828: sub start_finalcode {
  829:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  830: 
  831:     if ($target ne 'helper') {
  832:         return '';
  833:     }
  834:     
  835:     $paramHash->{FINAL_CODE} = &Apache::lonxml::get_all_text('/finalcode',
  836:                                                              $parser);
  837:     return '';
  838: }
  839: 
  840: sub end_finalcode { return ''; }
  841: 
  842: sub start_defaultvalue {
  843:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  844: 
  845:     if ($target ne 'helper') {
  846:         return '';
  847:     }
  848:     
  849:     $paramHash->{DEFAULT_VALUE} = &Apache::lonxml::get_all_text('/defaultvalue',
  850:                                                              $parser);
  851:     $paramHash->{DEFAULT_VALUE} = 'sub { my $helper = shift; my $state = shift;' .
  852:         $paramHash->{DEFAULT_VALUE} . '}';
  853:     return '';
  854: }
  855: 
  856: sub end_defaultvalue { return ''; }
  857: 
  858: sub preprocess {
  859:     return 1;
  860: }
  861: 
  862: sub postprocess {
  863:     return 1;
  864: }
  865: 
  866: sub render {
  867:     return '';
  868: }
  869: 
  870: sub overrideForm {
  871:     return 0;
  872: }
  873: 
  874: sub getValue {
  875:     my $self = shift;
  876:     return $helper->{VARS}->{$self->{'variable'}};
  877: }
  878: 
  879: 1;
  880: 
  881: package Apache::lonhelper::message;
  882: 
  883: =pod
  884: 
  885: =head2 Element: message
  886: 
  887: Message elements display the contents of their <message_text> tags, and
  888: transition directly to the state in the <nextstate> tag. Example:
  889: 
  890:  <message>
  891:    <nextstate>GET_NAME</nextstate>
  892:    <message_text>This is the <b>message</b> the user will see, 
  893:                  <i>HTML allowed</i>.</message_text>
  894:    </message>
  895: 
  896: This will display the HTML message and transition to the <nextstate> if
  897: given. The HTML will be directly inserted into the helper, so if you don't
  898: want text to run together, you'll need to manually wrap the <message_text>
  899: in <p> tags, or whatever is appropriate for your HTML.
  900: 
  901: Message tags do not add in whitespace, so if you want it, you'll need to add
  902: it into states. This is done so you can inline some elements, such as 
  903: the <date> element, right between two messages, giving the appearence that 
  904: the <date> element appears inline. (Note the elements can not be embedded
  905: within each other.)
  906: 
  907: This is also a good template for creating your own new states, as it has
  908: very little code beyond the state template.
  909: 
  910: =cut
  911: 
  912: no strict;
  913: @ISA = ("Apache::lonhelper::element");
  914: use strict;
  915: 
  916: BEGIN {
  917:     &Apache::lonhelper::register('Apache::lonhelper::message',
  918:                               ('message'));
  919: }
  920: 
  921: sub new {
  922:     my $ref = Apache::lonhelper::element->new();
  923:     bless($ref);
  924: }
  925: 
  926: # CONSTRUCTION: Construct the message element from the XML
  927: sub start_message {
  928:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  929: 
  930:     if ($target ne 'helper') {
  931:         return '';
  932:     }
  933: 
  934:     $paramHash->{MESSAGE_TEXT} = &Apache::lonxml::get_all_text('/message',
  935:                                                                $parser);
  936: 
  937:     if (defined($token->[2]{'nextstate'})) {
  938:         $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
  939:     }
  940:     return '';
  941: }
  942: 
  943: sub end_message {
  944:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
  945: 
  946:     if ($target ne 'helper') {
  947:         return '';
  948:     }
  949:     Apache::lonhelper::message->new();
  950:     return '';
  951: }
  952: 
  953: sub render {
  954:     my $self = shift;
  955: 
  956:     return $self->{MESSAGE_TEXT};
  957: }
  958: # If a NEXTSTATE was given, switch to it
  959: sub postprocess {
  960:     my $self = shift;
  961:     if (defined($self->{NEXTSTATE})) {
  962:         $helper->changeState($self->{NEXTSTATE});
  963:     }
  964: 
  965:     return 1;
  966: }
  967: 1;
  968: 
  969: package Apache::lonhelper::choices;
  970: 
  971: =pod
  972: 
  973: =head2 Element: choices
  974: 
  975: Choice states provide a single choice to the user as a text selection box.
  976: A "choice" is two pieces of text, one which will be displayed to the user
  977: (the "human" value), and one which will be passed back to the program
  978: (the "computer" value). For instance, a human may choose from a list of
  979: resources on disk by title, while your program wants the file name.
  980: 
  981: <choices> takes an attribute "variable" to control which helper variable
  982: the result is stored in.
  983: 
  984: <choices> takes an attribute "multichoice" which, if set to a true
  985: value, will allow the user to select multiple choices.
  986: 
  987: <choices> takes an attribute "allowempty" which, if set to a true 
  988: value, will allow the user to select none of the choices without raising
  989: an error message.
  990: 
  991: B<SUB-TAGS>
  992: 
  993: <choices> can have the following subtags:
  994: 
  995: =over 4
  996: 
  997: =item * <nextstate>state_name</nextstate>: If given, this will cause the
  998:       choice element to transition to the given state after executing. If
  999:       this is used, do not pass nextstates to the <choice> tag.
 1000: 
 1001: =item * <choice />: If the choices are static,
 1002:       this element will allow you to specify them. Each choice
 1003:       contains  attribute, "computer", as described above. The
 1004:       content of the tag will be used as the human label.
 1005:       For example,  
 1006:       <choice computer='234-12-7312'>Bobby McDormik</choice>.
 1007: 
 1008:       <choice> can take a parameter "eval", which if set to
 1009:       a true value, will cause the contents of the tag to be
 1010:       evaluated as it would be in an <eval> tag; see <eval> tag
 1011:       below.
 1012: 
 1013: <choice> may optionally contain a 'nextstate' attribute, which
 1014: will be the state transisitoned to if the choice is made, if
 1015: the choice is not multichoice.
 1016: 
 1017: =back
 1018: 
 1019: To create the choices programmatically, either wrap the choices in 
 1020: <condition> tags (prefered), or use an <exec> block inside the <choice>
 1021: tag. Store the choices in $state->{CHOICES}, which is a list of list
 1022: references, where each list has three strings. The first is the human
 1023: name, the second is the computer name. and the third is the option
 1024: next state. For example:
 1025: 
 1026:  <exec>
 1027:     for (my $i = 65; $i < 65 + 26; $i++) {
 1028:         push @{$state->{CHOICES}}, [chr($i), $i, 'next'];
 1029:     }
 1030:  </exec>
 1031: 
 1032: This will allow the user to select from the letters A-Z (in ASCII), while
 1033: passing the ASCII value back into the helper variables, and the state
 1034: will in all cases transition to 'next'.
 1035: 
 1036: You can mix and match methods of creating choices, as long as you always 
 1037: "push" onto the choice list, rather then wiping it out. (You can even 
 1038: remove choices programmatically, but that would probably be bad form.)
 1039: 
 1040: B<defaultvalue support>
 1041: 
 1042: Choices supports default values both in multichoice and single choice mode.
 1043: In single choice mode, have the defaultvalue tag's function return the 
 1044: computer value of the box you want checked. If the function returns a value
 1045: that does not correspond to any of the choices, the default behavior of selecting
 1046: the first choice will be preserved.
 1047: 
 1048: For multichoice, return a string with the computer values you want checked,
 1049: delimited by triple pipes. Note this matches how the result of the <choices>
 1050: tag is stored in the {VARS} hash.
 1051: 
 1052: =cut
 1053: 
 1054: no strict;
 1055: @ISA = ("Apache::lonhelper::element");
 1056: use strict;
 1057: 
 1058: BEGIN {
 1059:     &Apache::lonhelper::register('Apache::lonhelper::choices',
 1060:                               ('choice', 'choices'));
 1061: }
 1062: 
 1063: sub new {
 1064:     my $ref = Apache::lonhelper::element->new();
 1065:     bless($ref);
 1066: }
 1067: 
 1068: # CONSTRUCTION: Construct the message element from the XML
 1069: sub start_choices {
 1070:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1071: 
 1072:     if ($target ne 'helper') {
 1073:         return '';
 1074:     }
 1075: 
 1076:     # Need to initialize the choices list, so everything can assume it exists
 1077:     $paramHash->{'variable'} = $token->[2]{'variable'} if (!defined($paramHash->{'variable'}));
 1078:     $helper->declareVar($paramHash->{'variable'});
 1079:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
 1080:     $paramHash->{'allowempty'} = $token->[2]{'allowempty'};
 1081:     $paramHash->{CHOICES} = [];
 1082:     return '';
 1083: }
 1084: 
 1085: sub end_choices {
 1086:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1087: 
 1088:     if ($target ne 'helper') {
 1089:         return '';
 1090:     }
 1091:     Apache::lonhelper::choices->new();
 1092:     return '';
 1093: }
 1094: 
 1095: sub start_choice {
 1096:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1097: 
 1098:     if ($target ne 'helper') {
 1099:         return '';
 1100:     }
 1101: 
 1102:     my $computer = $token->[2]{'computer'};
 1103:     my $human = &Apache::lonxml::get_all_text('/choice',
 1104:                                               $parser);
 1105:     my $nextstate = $token->[2]{'nextstate'};
 1106:     my $evalFlag = $token->[2]{'eval'};
 1107:     push @{$paramHash->{CHOICES}}, [$human, $computer, $nextstate, 
 1108:                                     $evalFlag];
 1109:     return '';
 1110: }
 1111: 
 1112: sub end_choice {
 1113:     return '';
 1114: }
 1115: 
 1116: sub render {
 1117:     # START HERE: Replace this with correct choices code.
 1118:     my $self = shift;
 1119:     my $var = $self->{'variable'};
 1120:     my $buttons = '';
 1121:     my $result = '';
 1122: 
 1123:     if ($self->{'multichoice'}) {
 1124:         $result .= <<SCRIPT;
 1125: <script>
 1126:     function checkall(value, checkName) {
 1127: 	for (i=0; i<document.forms.helpform.elements.length; i++) {
 1128:             ele = document.forms.helpform.elements[i];
 1129:             if (ele.name == checkName + '.forminput') {
 1130:                 document.forms.helpform.elements[i].checked=value;
 1131:             }
 1132:         }
 1133:     }
 1134: </script>
 1135: SCRIPT
 1136:     }
 1137: 
 1138:     # Only print "select all" and "unselect all" if there are five or
 1139:     # more choices; fewer then that and it looks silly.
 1140:     if ($self->{'multichoice'} && scalar(@{$self->{CHOICES}}) > 4) {
 1141:         $buttons = <<BUTTONS;
 1142: <br />
 1143: <input type="button" onclick="checkall(true, '$var')" value="Select All" />
 1144: <input type="button" onclick="checkall(false, '$var')" value="Unselect All" />
 1145: <br />&nbsp;
 1146: BUTTONS
 1147:     }
 1148: 
 1149:     if (defined $self->{ERROR_MSG}) {
 1150:         $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br />';
 1151:     }
 1152: 
 1153:     $result .= $buttons;
 1154:     
 1155:     $result .= "<table>\n\n";
 1156: 
 1157:     my %checkedChoices;
 1158:     my $checkedChoicesFunc;
 1159: 
 1160:     if (defined($self->{DEFAULT_VALUE})) {
 1161:         $checkedChoicesFunc = eval ($self->{DEFAULT_VALUE});
 1162:         die 'Error in default value code for variable ' . 
 1163:             {'variable'} . ', Perl said:' . $@ if $@;
 1164:     } else {
 1165:         $checkedChoicesFunc = sub { return ''; };
 1166:     }
 1167: 
 1168:     # Process which choices should be checked.
 1169:     if ($self->{'multichoice'}) {
 1170:         for my $selectedChoice (split(/\|\|\|/, (&$checkedChoicesFunc($helper, $self)))) {
 1171:             $checkedChoices{$selectedChoice} = 1;
 1172:         }
 1173:     } else {
 1174:         # single choice
 1175:         my $selectedChoice = &$checkedChoicesFunc($helper, $self);
 1176:         
 1177:         my $foundChoice = 0;
 1178:         
 1179:         # check that the choice is in the list of choices.
 1180:         for my $choice (@{$self->{CHOICES}}) {
 1181:             if ($choice->[1] eq $selectedChoice) {
 1182:                 $checkedChoices{$choice->[1]} = 1;
 1183:                 $foundChoice = 1;
 1184:             }
 1185:         }
 1186:         
 1187:         # If we couldn't find the choice, pick the first one 
 1188:         if (!$foundChoice) {
 1189:             $checkedChoices{$self->{CHOICES}->[0]->[1]} = 1;
 1190:         }
 1191:     }
 1192: 
 1193:     my $type = "radio";
 1194:     if ($self->{'multichoice'}) { $type = 'checkbox'; }
 1195:     foreach my $choice (@{$self->{CHOICES}}) {
 1196:         $result .= "<tr>\n<td width='20'>&nbsp;</td>\n";
 1197:         $result .= "<td valign='top'><input type='$type' name='$var.forminput'"
 1198:             . "' value='" . 
 1199:             HTML::Entities::encode($choice->[1]) 
 1200:             . "'";
 1201:         if ($checkedChoices{$choice->[1]}) {
 1202:             $result .= " checked ";
 1203:         }
 1204:         my $choiceLabel = $choice->[0];
 1205:         if ($choice->[4]) {  # if we need to evaluate this choice
 1206:             $choiceLabel = "sub { my $helper = shift; my $state = shift;" .
 1207:                 $choiceLabel . "}";
 1208:             $choiceLabel = eval($choiceLabel);
 1209:             $choiceLabel = &$choiceLabel($helper, $self);
 1210:         }
 1211:         $result .= "/></td><td> " . $choiceLabel . "</td></tr>\n";
 1212:     }
 1213:     $result .= "</table>\n\n\n";
 1214:     $result .= $buttons;
 1215: 
 1216:     return $result;
 1217: }
 1218: 
 1219: # If a NEXTSTATE was given or a nextstate for this choice was
 1220: # given, switch to it
 1221: sub postprocess {
 1222:     my $self = shift;
 1223:     my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};
 1224: 
 1225:     if (!defined($chosenValue) && !$self->{'allowempty'}) {
 1226:         $self->{ERROR_MSG} = "You must choose one or more choices to" .
 1227:             " continue.";
 1228:         return 0;
 1229:     }
 1230: 
 1231:     if (ref($chosenValue)) {
 1232:         $helper->{VARS}->{$self->{'variable'}} = join('|||', @$chosenValue);
 1233:     }
 1234: 
 1235:     if (defined($self->{NEXTSTATE})) {
 1236:         $helper->changeState($self->{NEXTSTATE});
 1237:     }
 1238:     
 1239:     foreach my $choice (@{$self->{CHOICES}}) {
 1240:         if ($choice->[1] eq $chosenValue) {
 1241:             if (defined($choice->[2])) {
 1242:                 $helper->changeState($choice->[2]);
 1243:             }
 1244:         }
 1245:     }
 1246:     return 1;
 1247: }
 1248: 1;
 1249: 
 1250: package Apache::lonhelper::date;
 1251: 
 1252: =pod
 1253: 
 1254: =head2 Element: date
 1255: 
 1256: Date elements allow the selection of a date with a drop down list.
 1257: 
 1258: Date elements can take two attributes:
 1259: 
 1260: =over 4
 1261: 
 1262: =item * B<variable>: The name of the variable to store the chosen
 1263:         date in. Required.
 1264: 
 1265: =item * B<hoursminutes>: If a true value, the date will show hours
 1266:         and minutes, as well as month/day/year. If false or missing,
 1267:         the date will only show the month, day, and year.
 1268: 
 1269: =back
 1270: 
 1271: Date elements contain only an option <nextstate> tag to determine
 1272: the next state.
 1273: 
 1274: Example:
 1275: 
 1276:  <date variable="DUE_DATE" hoursminutes="1">
 1277:    <nextstate>choose_why</nextstate>
 1278:    </date>
 1279: 
 1280: =cut
 1281: 
 1282: no strict;
 1283: @ISA = ("Apache::lonhelper::element");
 1284: use strict;
 1285: 
 1286: use Time::localtime;
 1287: 
 1288: BEGIN {
 1289:     &Apache::lonhelper::register('Apache::lonhelper::date',
 1290:                               ('date'));
 1291: }
 1292: 
 1293: # Don't need to override the "new" from element
 1294: sub new {
 1295:     my $ref = Apache::lonhelper::element->new();
 1296:     bless($ref);
 1297: }
 1298: 
 1299: my @months = ("January", "February", "March", "April", "May", "June", "July",
 1300: 	      "August", "September", "October", "November", "December");
 1301: 
 1302: # CONSTRUCTION: Construct the message element from the XML
 1303: sub start_date {
 1304:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1305: 
 1306:     if ($target ne 'helper') {
 1307:         return '';
 1308:     }
 1309: 
 1310:     $paramHash->{'variable'} = $token->[2]{'variable'};
 1311:     $helper->declareVar($paramHash->{'variable'});
 1312:     $paramHash->{'hoursminutes'} = $token->[2]{'hoursminutes'};
 1313: }
 1314: 
 1315: sub end_date {
 1316:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1317: 
 1318:     if ($target ne 'helper') {
 1319:         return '';
 1320:     }
 1321:     Apache::lonhelper::date->new();
 1322:     return '';
 1323: }
 1324: 
 1325: sub render {
 1326:     my $self = shift;
 1327:     my $result = "";
 1328:     my $var = $self->{'variable'};
 1329: 
 1330:     my $date;
 1331:     
 1332:     # Default date: The current hour.
 1333:     $date = localtime();
 1334:     $date->min(0);
 1335: 
 1336:     if (defined $self->{ERROR_MSG}) {
 1337:         $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
 1338:     }
 1339: 
 1340:     # Month
 1341:     my $i;
 1342:     $result .= "<select name='${var}month'>\n";
 1343:     for ($i = 0; $i < 12; $i++) {
 1344:         if ($i == $date->mon) {
 1345:             $result .= "<option value='$i' selected>";
 1346:         } else {
 1347:             $result .= "<option value='$i'>";
 1348:         }
 1349:         $result .= $months[$i] . "</option>\n";
 1350:     }
 1351:     $result .= "</select>\n";
 1352: 
 1353:     # Day
 1354:     $result .= "<select name='${var}day'>\n";
 1355:     for ($i = 1; $i < 32; $i++) {
 1356:         if ($i == $date->mday) {
 1357:             $result .= '<option selected>';
 1358:         } else {
 1359:             $result .= '<option>';
 1360:         }
 1361:         $result .= "$i</option>\n";
 1362:     }
 1363:     $result .= "</select>,\n";
 1364: 
 1365:     # Year
 1366:     $result .= "<select name='${var}year'>\n";
 1367:     for ($i = 2000; $i < 2030; $i++) { # update this after 64-bit dates
 1368:         if ($date->year + 1900 == $i) {
 1369:             $result .= "<option selected>";
 1370:         } else {
 1371:             $result .= "<option>";
 1372:         }
 1373:         $result .= "$i</option>\n";
 1374:     }
 1375:     $result .= "</select>,\n";
 1376: 
 1377:     # Display Hours and Minutes if they are called for
 1378:     if ($self->{'hoursminutes'}) {
 1379:         # Build hour
 1380:         $result .= "<select name='${var}hour'>\n";
 1381:         $result .= "<option " . ($date->hour == 0 ? 'selected ':'') .
 1382:             " value='0'>midnight</option>\n";
 1383:         for ($i = 1; $i < 12; $i++) {
 1384:             if ($date->hour == $i) {
 1385:                 $result .= "<option selected value='$i'>$i a.m.</option>\n";
 1386:             } else {
 1387:                 $result .= "<option value='$i'>$i a.m</option>\n";
 1388:             }
 1389:         }
 1390:         $result .= "<option " . ($date->hour == 12 ? 'selected ':'') .
 1391:             " value='12'>noon</option>\n";
 1392:         for ($i = 13; $i < 24; $i++) {
 1393:             my $printedHour = $i - 12;
 1394:             if ($date->hour == $i) {
 1395:                 $result .= "<option selected value='$i'>$printedHour p.m.</option>\n";
 1396:             } else {
 1397:                 $result .= "<option value='$i'>$printedHour p.m.</option>\n";
 1398:             }
 1399:         }
 1400: 
 1401:         $result .= "</select> :\n";
 1402: 
 1403:         $result .= "<select name='${var}minute'>\n";
 1404:         for ($i = 0; $i < 60; $i++) {
 1405:             my $printedMinute = $i;
 1406:             if ($i < 10) {
 1407:                 $printedMinute = "0" . $printedMinute;
 1408:             }
 1409:             if ($date->min == $i) {
 1410:                 $result .= "<option selected>";
 1411:             } else {
 1412:                 $result .= "<option>";
 1413:             }
 1414:             $result .= "$printedMinute</option>\n";
 1415:         }
 1416:         $result .= "</select>\n";
 1417:     }
 1418: 
 1419:     return $result;
 1420: 
 1421: }
 1422: # If a NEXTSTATE was given, switch to it
 1423: sub postprocess {
 1424:     my $self = shift;
 1425:     my $var = $self->{'variable'};
 1426:     my $month = $ENV{'form.' . $var . 'month'}; 
 1427:     my $day = $ENV{'form.' . $var . 'day'}; 
 1428:     my $year = $ENV{'form.' . $var . 'year'}; 
 1429:     my $min = 0; 
 1430:     my $hour = 0;
 1431:     if ($self->{'hoursminutes'}) {
 1432:         $min = $ENV{'form.' . $var . 'minute'};
 1433:         $hour = $ENV{'form.' . $var . 'hour'};
 1434:     }
 1435: 
 1436:     my $chosenDate = Time::Local::timelocal(0, $min, $hour, $day, $month, $year);
 1437:     # Check to make sure that the date was not automatically co-erced into a 
 1438:     # valid date, as we want to flag that as an error
 1439:     # This happens for "Feb. 31", for instance, which is coerced to March 2 or
 1440:     # 3, depending on if it's a leapyear
 1441:     my $checkDate = localtime($chosenDate);
 1442: 
 1443:     if ($checkDate->mon != $month || $checkDate->mday != $day ||
 1444:         $checkDate->year + 1900 != $year) {
 1445:         $self->{ERROR_MSG} = "Can't use " . $months[$month] . " $day, $year as a "
 1446:             . "date because it doesn't exist. Please enter a valid date.";
 1447:         return 0;
 1448:     }
 1449: 
 1450:     $helper->{VARS}->{$var} = $chosenDate;
 1451: 
 1452:     if (defined($self->{NEXTSTATE})) {
 1453:         $helper->changeState($self->{NEXTSTATE});
 1454:     }
 1455: 
 1456:     return 1;
 1457: }
 1458: 1;
 1459: 
 1460: package Apache::lonhelper::resource;
 1461: 
 1462: =pod
 1463: 
 1464: =head2 Element: resource
 1465: 
 1466: <resource> elements allow the user to select one or multiple resources
 1467: from the current course. You can filter out which resources they can view,
 1468: and filter out which resources they can select. The course will always
 1469: be displayed fully expanded, because of the difficulty of maintaining
 1470: selections across folder openings and closings. If this is fixed, then
 1471: the user can manipulate the folders.
 1472: 
 1473: <resource> takes the standard variable attribute to control what helper
 1474: variable stores the results. It also takes a "multichoice" attribute,
 1475: which controls whether the user can select more then one resource. The 
 1476: "toponly" attribute controls whether the resource display shows just the
 1477: resources in that sequence, or recurses into all sub-sequences, defaulting
 1478: to false. The "suppressEmptySequences" attribute reflects the 
 1479: suppressEmptySequences argument to the render routine, which will cause
 1480: folders that have all of their contained resources filtered out to also
 1481: be filtered out.
 1482: 
 1483: B<SUB-TAGS>
 1484: 
 1485: =over 4
 1486: 
 1487: =item * <filterfunc>: If you want to filter what resources are displayed
 1488:   to the user, use a filter func. The <filterfunc> tag should contain
 1489:   Perl code that when wrapped with "sub { my $res = shift; " and "}" is 
 1490:   a function that returns true if the resource should be displayed, 
 1491:   and false if it should be skipped. $res is a resource object. 
 1492:   (See Apache::lonnavmaps documentation for information about the 
 1493:   resource object.)
 1494: 
 1495: =item * <choicefunc>: Same as <filterfunc>, except that controls whether
 1496:   the given resource can be chosen. (It is almost always a good idea to
 1497:   show the user the folders, for instance, but you do not always want to 
 1498:   let the user select them.)
 1499: 
 1500: =item * <nextstate>: Standard nextstate behavior.
 1501: 
 1502: =item * <valuefunc>: This function controls what is returned by the resource
 1503:   when the user selects it. Like filterfunc and choicefunc, it should be
 1504:   a function fragment that when wrapped by "sub { my $res = shift; " and
 1505:   "}" returns a string representing what you want to have as the value. By
 1506:   default, the value will be the resource ID of the object ($res->{ID}).
 1507: 
 1508: =item * <mapurl>: If the URL of a map is given here, only that map
 1509:   will be displayed, instead of the whole course.
 1510: 
 1511: =back
 1512: 
 1513: =cut
 1514: 
 1515: no strict;
 1516: @ISA = ("Apache::lonhelper::element");
 1517: use strict;
 1518: 
 1519: BEGIN {
 1520:     &Apache::lonhelper::register('Apache::lonhelper::resource',
 1521:                               ('resource', 'filterfunc', 
 1522:                                'choicefunc', 'valuefunc',
 1523:                                'mapurl'));
 1524: }
 1525: 
 1526: sub new {
 1527:     my $ref = Apache::lonhelper::element->new();
 1528:     bless($ref);
 1529: }
 1530: 
 1531: # CONSTRUCTION: Construct the message element from the XML
 1532: sub start_resource {
 1533:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1534: 
 1535:     if ($target ne 'helper') {
 1536:         return '';
 1537:     }
 1538: 
 1539:     $paramHash->{'variable'} = $token->[2]{'variable'};
 1540:     $helper->declareVar($paramHash->{'variable'});
 1541:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
 1542:     $paramHash->{'suppressEmptySequences'} = $token->[2]{'suppressEmptySequences'};
 1543:     $paramHash->{'toponly'} = $token->[2]{'toponly'};
 1544:     return '';
 1545: }
 1546: 
 1547: sub end_resource {
 1548:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1549: 
 1550:     if ($target ne 'helper') {
 1551:         return '';
 1552:     }
 1553:     if (!defined($paramHash->{FILTER_FUNC})) {
 1554:         $paramHash->{FILTER_FUNC} = sub {return 1;};
 1555:     }
 1556:     if (!defined($paramHash->{CHOICE_FUNC})) {
 1557:         $paramHash->{CHOICE_FUNC} = sub {return 1;};
 1558:     }
 1559:     if (!defined($paramHash->{VALUE_FUNC})) {
 1560:         $paramHash->{VALUE_FUNC} = sub {my $res = shift; return $res->{ID}; };
 1561:     }
 1562:     Apache::lonhelper::resource->new();
 1563:     return '';
 1564: }
 1565: 
 1566: sub start_filterfunc {
 1567:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1568: 
 1569:     if ($target ne 'helper') {
 1570:         return '';
 1571:     }
 1572: 
 1573:     my $contents = Apache::lonxml::get_all_text('/filterfunc',
 1574:                                                 $parser);
 1575:     $contents = 'sub { my $res = shift; ' . $contents . '}';
 1576:     $paramHash->{FILTER_FUNC} = eval $contents;
 1577: }
 1578: 
 1579: sub end_filterfunc { return ''; }
 1580: 
 1581: sub start_choicefunc {
 1582:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1583: 
 1584:     if ($target ne 'helper') {
 1585:         return '';
 1586:     }
 1587: 
 1588:     my $contents = Apache::lonxml::get_all_text('/choicefunc',
 1589:                                                 $parser);
 1590:     $contents = 'sub { my $res = shift; ' . $contents . '}';
 1591:     $paramHash->{CHOICE_FUNC} = eval $contents;
 1592: }
 1593: 
 1594: sub end_choicefunc { return ''; }
 1595: 
 1596: sub start_valuefunc {
 1597:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1598: 
 1599:     if ($target ne 'helper') {
 1600:         return '';
 1601:     }
 1602: 
 1603:     my $contents = Apache::lonxml::get_all_text('/valuefunc',
 1604:                                                 $parser);
 1605:     $contents = 'sub { my $res = shift; ' . $contents . '}';
 1606:     $paramHash->{VALUE_FUNC} = eval $contents;
 1607: }
 1608: 
 1609: sub end_valuefunc { return ''; }
 1610: 
 1611: sub start_mapurl {
 1612:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1613: 
 1614:     if ($target ne 'helper') {
 1615:         return '';
 1616:     }
 1617: 
 1618:     my $contents = Apache::lonxml::get_all_text('/mapurl',
 1619:                                                 $parser);
 1620:     $paramHash->{MAP_URL} = $contents;
 1621: }
 1622: 
 1623: sub end_mapurl { return ''; }
 1624: 
 1625: # A note, in case I don't get to this before I leave.
 1626: # If someone complains about the "Back" button returning them
 1627: # to the previous folder state, instead of returning them to
 1628: # the previous helper state, the *correct* answer is for the helper
 1629: # to keep track of how many times the user has manipulated the folders,
 1630: # and feed that to the history.go() call in the helper rendering routines.
 1631: # If done correctly, the helper itself can keep track of how many times
 1632: # it renders the same states, so it doesn't go in just this state, and
 1633: # you can lean on the browser back button to make sure it all chains
 1634: # correctly.
 1635: # Right now, though, I'm just forcing all folders open.
 1636: 
 1637: sub render {
 1638:     my $self = shift;
 1639:     my $result = "";
 1640:     my $var = $self->{'variable'};
 1641:     my $curVal = $helper->{VARS}->{$var};
 1642: 
 1643:     my $buttons = '';
 1644: 
 1645:     if ($self->{'multichoice'}) {
 1646:         $result = <<SCRIPT;
 1647: <script>
 1648:     function checkall(value, checkName) {
 1649: 	for (i=0; i<document.forms.helpform.elements.length; i++) {
 1650:             ele = document.forms.helpform.elements[i];
 1651:             if (ele.name == checkName + '.forminput') {
 1652:                 document.forms.helpform.elements[i].checked=value;
 1653:             }
 1654:         }
 1655:     }
 1656: </script>
 1657: SCRIPT
 1658:         $buttons = <<BUTTONS;
 1659: <br /> &nbsp;
 1660: <input type="button" onclick="checkall(true, '$var')" value="Select All Resources" />
 1661: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Resources" />
 1662: <br /> &nbsp;
 1663: BUTTONS
 1664:     }
 1665: 
 1666:     if (defined $self->{ERROR_MSG}) {
 1667:         $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
 1668:     }
 1669: 
 1670:     $result .= $buttons;
 1671: 
 1672:     my $filterFunc = $self->{FILTER_FUNC};
 1673:     my $choiceFunc = $self->{CHOICE_FUNC};
 1674:     my $valueFunc = $self->{VALUE_FUNC};
 1675:     my $mapUrl = $self->{MAP_URL};
 1676:     my $multichoice = $self->{'multichoice'};
 1677: 
 1678:     # Create the composite function that renders the column on the nav map
 1679:     # have to admit any language that lets me do this can't be all bad
 1680:     #  - Jeremy (Pythonista) ;-)
 1681:     my $checked = 0;
 1682:     my $renderColFunc = sub {
 1683:         my ($resource, $part, $params) = @_;
 1684: 
 1685:         my $inputType;
 1686:         if ($multichoice) { $inputType = 'checkbox'; }
 1687:         else {$inputType = 'radio'; }
 1688: 
 1689:         if (!&$choiceFunc($resource)) {
 1690:             return '<td>&nbsp;</td>';
 1691:         } else {
 1692:             my $col = "<td><input type='$inputType' name='${var}.forminput' ";
 1693:             if (!$checked && !$multichoice) {
 1694:                 $col .= "checked ";
 1695:                 $checked = 1;
 1696:             }
 1697:             $col .= "value='" . 
 1698:                 HTML::Entities::encode(&$valueFunc($resource)) 
 1699:                 . "' /></td>";
 1700:             return $col;
 1701:         }
 1702:     };
 1703: 
 1704:     $ENV{'form.condition'} = !$self->{'toponly'};
 1705:     $result .= 
 1706:         &Apache::lonnavmaps::render( { 'cols' => [$renderColFunc, 
 1707:                                                   Apache::lonnavmaps::resource()],
 1708:                                        'showParts' => 0,
 1709:                                        'filterFunc' => $filterFunc,
 1710:                                        'resource_no_folder_link' => 1,
 1711:                                        'suppressEmptySequences' => $self->{'suppressEmptySequences'},
 1712:                                        'iterator_map' => $mapUrl }
 1713:                                        );
 1714: 
 1715:     $result .= $buttons;
 1716:                                                 
 1717:     return $result;
 1718: }
 1719:     
 1720: sub postprocess {
 1721:     my $self = shift;
 1722: 
 1723:     if ($self->{'multichoice'} && !$helper->{VARS}->{$self->{'variable'}}) {
 1724:         $self->{ERROR_MSG} = 'You must choose at least one resource to continue.';
 1725:         return 0;
 1726:     }
 1727: 
 1728:     if (defined($self->{NEXTSTATE})) {
 1729:         $helper->changeState($self->{NEXTSTATE});
 1730:     }
 1731: 
 1732:     return 1;
 1733: }
 1734: 
 1735: 1;
 1736: 
 1737: package Apache::lonhelper::student;
 1738: 
 1739: =pod
 1740: 
 1741: =head2 Element: student
 1742: 
 1743: Student elements display a choice of students enrolled in the current
 1744: course. Currently it is primitive; this is expected to evolve later.
 1745: 
 1746: Student elements take two attributes: "variable", which means what
 1747: it usually does, and "multichoice", which if true allows the user
 1748: to select multiple students.
 1749: 
 1750: =cut
 1751: 
 1752: no strict;
 1753: @ISA = ("Apache::lonhelper::element");
 1754: use strict;
 1755: 
 1756: 
 1757: 
 1758: BEGIN {
 1759:     &Apache::lonhelper::register('Apache::lonhelper::student',
 1760:                               ('student'));
 1761: }
 1762: 
 1763: sub new {
 1764:     my $ref = Apache::lonhelper::element->new();
 1765:     bless($ref);
 1766: }
 1767: 
 1768: sub start_student {
 1769:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1770: 
 1771:     if ($target ne 'helper') {
 1772:         return '';
 1773:     }
 1774: 
 1775:     $paramHash->{'variable'} = $token->[2]{'variable'};
 1776:     $helper->declareVar($paramHash->{'variable'});
 1777:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
 1778:     if (defined($token->[2]{'nextstate'})) {
 1779:         $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
 1780:     }
 1781:     
 1782: }    
 1783: 
 1784: sub end_student {
 1785:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1786: 
 1787:     if ($target ne 'helper') {
 1788:         return '';
 1789:     }
 1790:     Apache::lonhelper::student->new();
 1791: }
 1792: 
 1793: sub render {
 1794:     my $self = shift;
 1795:     my $result = '';
 1796:     my $buttons = '';
 1797:     my $var = $self->{'variable'};
 1798: 
 1799:     if ($self->{'multichoice'}) {
 1800:         $result = <<SCRIPT;
 1801: <script>
 1802:     function checkall(value, checkName) {
 1803: 	for (i=0; i<document.forms.helpform.elements.length; i++) {
 1804:             ele = document.forms.helpform.elements[i];
 1805:             if (ele.name == checkName + '.forminput') {
 1806:                 document.forms.helpform.elements[i].checked=value;
 1807:             }
 1808:         }
 1809:     }
 1810: </script>
 1811: SCRIPT
 1812:         $buttons = <<BUTTONS;
 1813: <br />
 1814: <input type="button" onclick="checkall(true, '$var')" value="Select All Students" />
 1815: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Students" />
 1816: <br />
 1817: BUTTONS
 1818:     }
 1819: 
 1820:     if (defined $self->{ERROR_MSG}) {
 1821:         $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
 1822:     }
 1823: 
 1824:     # Load up the students
 1825:     my $choices = &Apache::loncoursedata::get_classlist();
 1826:     my @keys = keys %{$choices};
 1827: 
 1828:     # Constants
 1829:     my $section = Apache::loncoursedata::CL_SECTION();
 1830:     my $fullname = Apache::loncoursedata::CL_FULLNAME();
 1831: 
 1832:     # Sort by: Section, name
 1833:     @keys = sort {
 1834:         if ($choices->{$a}->[$section] ne $choices->{$b}->[$section]) {
 1835:             return $choices->{$a}->[$section] cmp $choices->{$b}->[$section];
 1836:         }
 1837:         return $choices->{$a}->[$fullname] cmp $choices->{$b}->[$fullname];
 1838:     } @keys;
 1839: 
 1840:     my $type = 'radio';
 1841:     if ($self->{'multichoice'}) { $type = 'checkbox'; }
 1842:     $result .= "<table cellspacing='2' cellpadding='2' border='0'>\n";
 1843:     $result .= "<tr><td></td><td align='center'><b>Student Name</b></td>".
 1844:         "<td align='center'><b>Section</b></td></tr>";
 1845: 
 1846:     my $checked = 0;
 1847:     foreach (@keys) {
 1848:         $result .= "<tr><td><input type='$type' name='" .
 1849:             $self->{'variable'} . '.forminput' . "'";
 1850:             
 1851:         if (!$self->{'multichoice'} && !$checked) {
 1852:             $result .= " checked ";
 1853:             $checked = 1;
 1854:         }
 1855:         $result .=
 1856:             " value='" . HTML::Entities::encode($_ . ':' . $choices->{$_}->[$section])
 1857:             . "' /></td><td>"
 1858:             . HTML::Entities::encode($choices->{$_}->[$fullname])
 1859:             . "</td><td align='center'>" 
 1860:             . HTML::Entities::encode($choices->{$_}->[$section])
 1861:             . "</td></tr>\n";
 1862:     }
 1863: 
 1864:     $result .= "</table>\n\n";
 1865:     $result .= $buttons;    
 1866:     
 1867:     return $result;
 1868: }
 1869: 
 1870: sub postprocess {
 1871:     my $self = shift;
 1872: 
 1873:     my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
 1874:     if (!$result) {
 1875:         $self->{ERROR_MSG} = 'You must choose at least one student '.
 1876:             'to continue.';
 1877:         return 0;
 1878:     }
 1879: 
 1880:     if (defined($self->{NEXTSTATE})) {
 1881:         $helper->changeState($self->{NEXTSTATE});
 1882:     }
 1883: 
 1884:     return 1;
 1885: }
 1886: 
 1887: 1;
 1888: 
 1889: package Apache::lonhelper::files;
 1890: 
 1891: =pod
 1892: 
 1893: =head2 Element: files
 1894: 
 1895: files allows the users to choose files from a given directory on the
 1896: server. It is always multichoice and stores the result as a triple-pipe
 1897: delimited entry in the helper variables. 
 1898: 
 1899: Since it is extremely unlikely that you can actually code a constant
 1900: representing the directory you wish to allow the user to search, <files>
 1901: takes a subroutine that returns the name of the directory you wish to
 1902: have the user browse.
 1903: 
 1904: files accepts the attribute "variable" to control where the files chosen
 1905: are put. It accepts the attribute "multichoice" as the other attribute,
 1906: defaulting to false, which if true will allow the user to select more
 1907: then one choice. 
 1908: 
 1909: <files> accepts three subtags. One is the "nextstate" sub-tag that works
 1910: as it does with the other tags. Another is a <filechoice> sub tag that
 1911: is Perl code that, when surrounded by "sub {" and "}" will return a
 1912: string representing what directory on the server to allow the user to 
 1913: choose files from. Finally, the <filefilter> subtag should contain Perl
 1914: code that when surrounded by "sub { my $filename = shift; " and "}",
 1915: returns a true value if the user can pick that file, or false otherwise.
 1916: The filename passed to the function will be just the name of the file, 
 1917: with no path info.
 1918: 
 1919: =cut
 1920: 
 1921: no strict;
 1922: @ISA = ("Apache::lonhelper::element");
 1923: use strict;
 1924: 
 1925: BEGIN {
 1926:     &Apache::lonhelper::register('Apache::lonhelper::files',
 1927:                                  ('files', 'filechoice', 'filefilter'));
 1928: }
 1929: 
 1930: sub new {
 1931:     my $ref = Apache::lonhelper::element->new();
 1932:     bless($ref);
 1933: }
 1934: 
 1935: sub start_files {
 1936:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1937: 
 1938:     if ($target ne 'helper') {
 1939:         return '';
 1940:     }
 1941:     $paramHash->{'variable'} = $token->[2]{'variable'};
 1942:     $helper->declareVar($paramHash->{'variable'});
 1943:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
 1944: }    
 1945: 
 1946: sub end_files {
 1947:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1948: 
 1949:     if ($target ne 'helper') {
 1950:         return '';
 1951:     }
 1952:     if (!defined($paramHash->{FILTER_FUNC})) {
 1953:         $paramHash->{FILTER_FUNC} = sub { return 1; };
 1954:     }
 1955:     Apache::lonhelper::files->new();
 1956: }    
 1957: 
 1958: sub start_filechoice {
 1959:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1960: 
 1961:     if ($target ne 'helper') {
 1962:         return '';
 1963:     }
 1964:     $paramHash->{'filechoice'} = Apache::lonxml::get_all_text('/filechoice',
 1965:                                                               $parser);
 1966: }
 1967: 
 1968: sub end_filechoice { return ''; }
 1969: 
 1970: sub start_filefilter {
 1971:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 1972: 
 1973:     if ($target ne 'helper') {
 1974:         return '';
 1975:     }
 1976: 
 1977:     my $contents = Apache::lonxml::get_all_text('/filefilter',
 1978:                                                 $parser);
 1979:     $contents = 'sub { my $filename = shift; ' . $contents . '}';
 1980:     $paramHash->{FILTER_FUNC} = eval $contents;
 1981: }
 1982: 
 1983: sub end_filefilter { return ''; }
 1984: 
 1985: sub render {
 1986:     my $self = shift;
 1987:     my $result = '';
 1988:     my $var = $self->{'variable'};
 1989:     
 1990:     my $subdirFunc = eval('sub {' . $self->{'filechoice'} . '}');
 1991:     die 'Error in resource filter code for variable ' . 
 1992:         {'variable'} . ', Perl said:' . $@ if $@;
 1993: 
 1994:     my $subdir = &$subdirFunc();
 1995: 
 1996:     my $filterFunc = $self->{FILTER_FUNC};
 1997:     my $buttons = '';
 1998:     my $type = 'radio';
 1999:     if ($self->{'multichoice'}) {
 2000:         $type = 'checkbox';
 2001:     }
 2002: 
 2003:     if ($self->{'multichoice'}) {
 2004:         $result = <<SCRIPT;
 2005: <script>
 2006:     function checkall(value, checkName) {
 2007: 	for (i=0; i<document.forms.helpform.elements.length; i++) {
 2008:             ele = document.forms.helpform.elements[i];
 2009:             if (ele.name == checkName + '.forminput') {
 2010:                 document.forms.helpform.elements[i].checked=value;
 2011:             }
 2012:         }
 2013:     }
 2014: 
 2015:     function checkallclass(value, className) {
 2016:         for (i=0; i<document.forms.helpform.elements.length; i++) {
 2017:             ele = document.forms.helpform.elements[i];
 2018:             if (ele.type == "$type" && ele.onclick) {
 2019:                 document.forms.helpform.elements[i].checked=value;
 2020:             }
 2021:         }
 2022:     }
 2023: </script>
 2024: SCRIPT
 2025:         $buttons = <<BUTTONS;
 2026: <br /> &nbsp;
 2027: <input type="button" onclick="checkall(true, '$var')" value="Select All Files" />
 2028: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Files" />
 2029: BUTTONS
 2030: 
 2031:         if ($helper->{VARS}->{'construction'}) {
 2032:             $buttons .= <<BUTTONS;
 2033: <input type="button" onclick="checkallclass(true, 'Published')" value="Select All Published" />
 2034: <input type="button" onclick="checkallclass(false, 'Published')" value="Unselect All Published" />
 2035: <br /> &nbsp;
 2036: BUTTONS
 2037:        }
 2038:     }
 2039: 
 2040:     # Get the list of files in this directory.
 2041:     my @fileList;
 2042: 
 2043:     # If the subdirectory is in local CSTR space
 2044:     if ($subdir =~ m|/home/([^/]+)/public_html|) {
 2045:         my $user = $1;
 2046:         my $domain = $Apache::lonnet::perlvar{'lonDefDomain'};
 2047:         @fileList = &Apache::lonnet::dirlist($subdir, $domain, $user, '');
 2048:     } else {
 2049:         # local library server resource space
 2050:         @fileList = &Apache::lonnet::dirlist($subdir, $ENV{'user.domain'}, $ENV{'user.name'}, '');
 2051:     }
 2052: 
 2053:     $result .= $buttons;
 2054: 
 2055:     if (defined $self->{ERROR_MSG}) {
 2056:         $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
 2057:     }
 2058: 
 2059:     $result .= '<table border="0" cellpadding="2" cellspacing="0">';
 2060: 
 2061:     # Keeps track if there are no choices, prints appropriate error
 2062:     # if there are none. 
 2063:     my $choices = 0;
 2064:     # Print each legitimate file choice.
 2065:     for my $file (@fileList) {
 2066:         $file = (split(/&/, $file))[0];
 2067:         if ($file eq '.' || $file eq '..') {
 2068:             next;
 2069:         }
 2070:         my $fileName = $subdir .'/'. $file;
 2071:         if (&$filterFunc($file)) {
 2072: 	    my $status;
 2073: 	    my $color;
 2074: 	    if ($helper->{VARS}->{'construction'}) {
 2075: 		($status, $color) = @{fileState($subdir, $file)};
 2076: 	    } else {
 2077: 		$status = '';
 2078: 		$color = '';
 2079: 	    }
 2080: 
 2081:             # Netscape 4 is stupid and there's nowhere to put the
 2082:             # information on the input tag that the file is Published,
 2083:             # Unpublished, etc. In *real* browsers we can just say
 2084:             # "class='Published'" and check the className attribute of
 2085:             # the input tag, but Netscape 4 is too stupid to understand
 2086:             # that attribute, and un-comprehended attributes are not
 2087:             # reflected into the object model. So instead, what I do 
 2088:             # is either have or don't have an "onclick" handler that 
 2089:             # does nothing, give Published files the onclick handler, and
 2090:             # have the checker scripts check for that. Stupid and clumsy,
 2091:             # and only gives us binary "yes/no" information (at least I
 2092:             # couldn't figure out how to reach into the event handler's
 2093:             # actual code to retreive a value), but it works well enough
 2094:             # here.
 2095:         
 2096:             my $onclick = '';
 2097:             if ($status eq 'Published' && $helper->{VARS}->{'construction'}) {
 2098:                 $onclick = 'onclick="a=1" ';
 2099:             }
 2100:             $result .= '<tr><td align="right"' . " bgcolor='$color'>" .
 2101:                 "<input $onclick type='$type' name='" . $var
 2102:             . ".forminput' value='" . HTML::Entities::encode($fileName) .
 2103:                 "'";
 2104:             if (!$self->{'multichoice'} && $choices == 0) {
 2105:                 $result .= ' checked';
 2106:             }
 2107:             $result .= "/></td><td bgcolor='$color'>" . $file .
 2108:                  "</td><td bgcolor='$color'>$status</td></tr>\n";
 2109:             $choices++;
 2110:         }
 2111:     }
 2112: 
 2113:     $result .= "</table>\n";
 2114: 
 2115:     if (!$choices) {
 2116:         $result .= '<font color="#FF0000">There are no files available to select in this directory. Please go back and select another option.</font><br /><br />';
 2117:     }
 2118: 
 2119:     $result .= $buttons;
 2120: 
 2121:     return $result;
 2122: }
 2123: 
 2124: # Determine the state of the file: Published, unpublished, modified.
 2125: # Return the color it should be in and a label as a two-element array
 2126: # reference.
 2127: # Logic lifted from lonpubdir.pm, even though I don't know that it's still
 2128: # the most right thing to do.
 2129: 
 2130: sub fileState {
 2131:     my $constructionSpaceDir = shift;
 2132:     my $file = shift;
 2133:     
 2134:     my $docroot = $Apache::lonnet::perlvar{'lonDocRoot'};
 2135:     my $subdirpart = $constructionSpaceDir;
 2136:     $subdirpart =~ s/^\/home\/$ENV{'user.name'}\/public_html//;
 2137:     my $resdir = $docroot . '/res/' . $ENV{'user.domain'} . '/' . $ENV{'user.name'} .
 2138:         $subdirpart;
 2139: 
 2140:     my @constructionSpaceFileStat = stat($constructionSpaceDir . '/' . $file);
 2141:     my @resourceSpaceFileStat = stat($resdir . '/' . $file);
 2142:     if (!@resourceSpaceFileStat) {
 2143:         return ['Unpublished', '#FFCCCC'];
 2144:     }
 2145: 
 2146:     my $constructionSpaceFileModified = $constructionSpaceFileStat[9];
 2147:     my $resourceSpaceFileModified = $resourceSpaceFileStat[9];
 2148:     
 2149:     if ($constructionSpaceFileModified > $resourceSpaceFileModified) {
 2150:         return ['Modified', '#FFFFCC'];
 2151:     }
 2152:     return ['Published', '#CCFFCC'];
 2153: }
 2154: 
 2155: sub postprocess {
 2156:     my $self = shift;
 2157:     my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
 2158:     if (!$result) {
 2159:         $self->{ERROR_MSG} = 'You must choose at least one file '.
 2160:             'to continue.';
 2161:         return 0;
 2162:     }
 2163: 
 2164:     if (defined($self->{NEXTSTATE})) {
 2165:         $helper->changeState($self->{NEXTSTATE});
 2166:     }
 2167: 
 2168:     return 1;
 2169: }
 2170: 
 2171: 1;
 2172: 
 2173: package Apache::lonhelper::section;
 2174: 
 2175: =pod
 2176: 
 2177: =head2 Element: section
 2178: 
 2179: <section> allows the user to choose one or more sections from the current
 2180: course.
 2181: 
 2182: It takes the standard attributes "variable", "multichoice", and
 2183: "nextstate", meaning what they do for most other elements.
 2184: 
 2185: =cut
 2186: 
 2187: no strict;
 2188: @ISA = ("Apache::lonhelper::choices");
 2189: use strict;
 2190: 
 2191: BEGIN {
 2192:     &Apache::lonhelper::register('Apache::lonhelper::section',
 2193:                                  ('section'));
 2194: }
 2195: 
 2196: sub new {
 2197:     my $ref = Apache::lonhelper::choices->new();
 2198:     bless($ref);
 2199: }
 2200: 
 2201: sub start_section {
 2202:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2203: 
 2204:     if ($target ne 'helper') {
 2205:         return '';
 2206:     }
 2207: 
 2208:     $paramHash->{CHOICES} = [];
 2209: 
 2210:     $paramHash->{'variable'} = $token->[2]{'variable'};
 2211:     $helper->declareVar($paramHash->{'variable'});
 2212:     $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
 2213:     if (defined($token->[2]{'nextstate'})) {
 2214:         $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
 2215:     }
 2216: 
 2217:     # Populate the CHOICES element
 2218:     my %choices;
 2219: 
 2220:     my $section = Apache::loncoursedata::CL_SECTION();
 2221:     my $classlist = Apache::loncoursedata::get_classlist();
 2222:     foreach (keys %$classlist) {
 2223:         my $sectionName = $classlist->{$_}->[$section];
 2224:         if (!$sectionName) {
 2225:             $choices{"No section assigned"} = "";
 2226:         } else {
 2227:             $choices{$sectionName} = $sectionName;
 2228:         }
 2229:     } 
 2230:    
 2231:     for my $sectionName (sort(keys(%choices))) {
 2232:         
 2233:         push @{$paramHash->{CHOICES}}, [$sectionName, $sectionName];
 2234:     }
 2235: }    
 2236: 
 2237: sub end_section {
 2238:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2239: 
 2240:     if ($target ne 'helper') {
 2241:         return '';
 2242:     }
 2243:     Apache::lonhelper::section->new();
 2244: }    
 2245: 1;
 2246: 
 2247: package Apache::lonhelper::general;
 2248: 
 2249: =pod
 2250: 
 2251: =head2 General-purpose tag: <exec>
 2252: 
 2253: The contents of the exec tag are executed as Perl code, not inside a 
 2254: safe space, so the full range of $ENV and such is available. The code
 2255: will be executed as a subroutine wrapped with the following code:
 2256: 
 2257: "sub { my $helper = shift; my $state = shift;" and
 2258: 
 2259: "}"
 2260: 
 2261: The return value is ignored.
 2262: 
 2263: $helper is the helper object. Feel free to add methods to the helper
 2264: object to support whatever manipulation you may need to do (for instance,
 2265: overriding the form location if the state is the final state; see 
 2266: lonparm.helper for an example).
 2267: 
 2268: $state is the $paramHash that has currently been generated and may
 2269: be manipulated by the code in exec. Note that the $state is not yet
 2270: an actual state B<object>, it is just a hash, so do not expect to
 2271: be able to call methods on it.
 2272: 
 2273: =cut
 2274: 
 2275: BEGIN {
 2276:     &Apache::lonhelper::register('Apache::lonhelper::general',
 2277:                                  'exec', 'condition', 'clause',
 2278:                                  'eval');
 2279: }
 2280: 
 2281: sub start_exec {
 2282:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2283: 
 2284:     if ($target ne 'helper') {
 2285:         return '';
 2286:     }
 2287:     
 2288:     my $code = &Apache::lonxml::get_all_text('/exec', $parser);
 2289:     
 2290:     $code = eval ('sub { my $helper = shift; my $state = shift; ' .
 2291:         $code . "}");
 2292:     die 'Error in <exec>, Perl said: '. $@ if $@;
 2293:     &$code($helper, $paramHash);
 2294: }
 2295: 
 2296: sub end_exec { return ''; }
 2297: 
 2298: =pod
 2299: 
 2300: =head2 General-purpose tag: <condition>
 2301: 
 2302: The <condition> tag allows you to mask out parts of the helper code
 2303: depending on some programatically determined condition. The condition
 2304: tag contains a tag <clause> which contains perl code that when wrapped
 2305: with "sub { my $helper = shift; my $state = shift; " and "}", returns
 2306: a true value if the XML in the condition should be evaluated as a normal
 2307: part of the helper, or false if it should be completely discarded.
 2308: 
 2309: The <clause> tag must be the first sub-tag of the <condition> tag or
 2310: it will not work as expected.
 2311: 
 2312: =cut
 2313: 
 2314: # The condition tag just functions as a marker, it doesn't have
 2315: # to "do" anything. Technically it doesn't even have to be registered
 2316: # with the lonxml code, but I leave this here to be explicit about it.
 2317: sub start_condition { return ''; }
 2318: sub end_condition { return ''; }
 2319: 
 2320: sub start_clause {
 2321:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2322: 
 2323:     if ($target ne 'helper') {
 2324:         return '';
 2325:     }
 2326:     
 2327:     my $clause = Apache::lonxml::get_all_text('/clause', $parser);
 2328:     $clause = eval('sub { my $helper = shift; my $state = shift; '
 2329:         . $clause . '}');
 2330:     die 'Error in clause of condition, Perl said: ' . $@ if $@;
 2331:     if (!&$clause($helper, $paramHash)) {
 2332:         # Discard all text until the /condition.
 2333:         &Apache::lonxml::get_all_text('/condition', $parser);
 2334:     }
 2335: }
 2336: 
 2337: sub end_clause { return ''; }
 2338: 
 2339: =pod
 2340: 
 2341: =head2 General-purpose tag: <eval>
 2342: 
 2343: The <eval> tag will be evaluated as a subroutine call passed in the
 2344: current helper object and state hash as described in <condition> above,
 2345: but is expected to return a string to be printed directly to the
 2346: screen. This is useful for dynamically generating messages. 
 2347: 
 2348: =cut
 2349: 
 2350: # This is basically a type of message.
 2351: # Programmatically setting $paramHash->{NEXTSTATE} would work, though
 2352: # it's probably bad form.
 2353: 
 2354: sub start_eval {
 2355:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2356: 
 2357:     if ($target ne 'helper') {
 2358:         return '';
 2359:     }
 2360:     
 2361:     my $program = Apache::lonxml::get_all_text('/eval', $parser);
 2362:     $program = eval('sub { my $helper = shift; my $state = shift; '
 2363:         . $program . '}');
 2364:     die 'Error in eval code, Perl said: ' . $@ if $@;
 2365:     $paramHash->{MESSAGE_TEXT} = &$program($helper, $paramHash);
 2366: }
 2367: 
 2368: sub end_eval { 
 2369:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2370: 
 2371:     if ($target ne 'helper') {
 2372:         return '';
 2373:     }
 2374: 
 2375:     Apache::lonhelper::message->new();
 2376: }
 2377: 
 2378: 1;
 2379: 
 2380: package Apache::lonhelper::final;
 2381: 
 2382: =pod
 2383: 
 2384: =head2 Element: final
 2385: 
 2386: <final> is a special element that works with helpers that use the <finalcode>
 2387: tag. It goes through all the states and elements, executing the <finalcode>
 2388: snippets and collecting the results. Finally, it takes the user out of the
 2389: helper, going to a provided page.
 2390: 
 2391: =cut
 2392: 
 2393: no strict;
 2394: @ISA = ("Apache::lonhelper::element");
 2395: use strict;
 2396: 
 2397: BEGIN {
 2398:     &Apache::lonhelper::register('Apache::lonhelper::final',
 2399:                                  ('final', 'exitpage'));
 2400: }
 2401: 
 2402: sub new {
 2403:     my $ref = Apache::lonhelper::element->new();
 2404:     bless($ref);
 2405: }
 2406: 
 2407: sub start_final { return ''; }
 2408: 
 2409: sub end_final {
 2410:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2411: 
 2412:     if ($target ne 'helper') {
 2413:         return '';
 2414:     }
 2415: 
 2416:     Apache::lonhelper::final->new();
 2417:    
 2418:     return '';
 2419: }
 2420: 
 2421: sub start_exitpage {
 2422:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2423: 
 2424:     if ($target ne 'helper') {
 2425:         return '';
 2426:     }
 2427: 
 2428:     $paramHash->{EXIT_PAGE} = &Apache::lonxml::get_all_text('/exitpage',
 2429:                                                             $parser);
 2430: 
 2431:     return '';
 2432: }
 2433: 
 2434: sub end_exitpage { return ''; }
 2435: 
 2436: sub render {
 2437:     my $self = shift;
 2438: 
 2439:     my @results;
 2440: 
 2441:     # Collect all the results
 2442:     for my $stateName (keys %{$helper->{STATES}}) {
 2443:         my $state = $helper->{STATES}->{$stateName};
 2444:         
 2445:         for my $element (@{$state->{ELEMENTS}}) {
 2446:             if (defined($element->{FINAL_CODE})) {
 2447:                 # Compile the code.
 2448:                 my $code = 'sub { my $helper = shift; my $element = shift; ' 
 2449:                     . $element->{FINAL_CODE} . '}';
 2450:                 $code = eval($code);
 2451:                 die 'Error while executing final code for element with var ' .
 2452:                     $element->{'variable'} . ', Perl said: ' . $@ if $@;
 2453: 
 2454:                 my $result = &$code($helper, $element);
 2455:                 if ($result) {
 2456:                     push @results, $result;
 2457:                 }
 2458:             }
 2459:         }
 2460:     }
 2461: 
 2462:     if (scalar(@results) == 0) {
 2463:         return '';
 2464:     }
 2465: 
 2466:     my $result = "<ul>\n";
 2467:     for my $re (@results) {
 2468:         $result .= '    <li>' . $re . "</li>\n";
 2469:     }
 2470:     return $result . '</ul>';
 2471: }
 2472: 
 2473: 1;
 2474: 
 2475: package Apache::lonhelper::parmwizfinal;
 2476: 
 2477: # This is the final state for the parmwizard. It is not generally useful,
 2478: # so it is not perldoc'ed. It does its own processing.
 2479: # It is represented with <parmwizfinal />, and
 2480: # should later be moved to lonparmset.pm .
 2481: 
 2482: no strict;
 2483: @ISA = ('Apache::lonhelper::element');
 2484: use strict;
 2485: 
 2486: BEGIN {
 2487:     &Apache::lonhelper::register('Apache::lonhelper::parmwizfinal',
 2488:                                  ('parmwizfinal'));
 2489: }
 2490: 
 2491: use Time::localtime;
 2492: 
 2493: sub new {
 2494:     my $ref = Apache::lonhelper::choices->new();
 2495:     bless ($ref);
 2496: }
 2497: 
 2498: sub start_parmwizfinal { return ''; }
 2499: 
 2500: sub end_parmwizfinal {
 2501:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
 2502: 
 2503:     if ($target ne 'helper') {
 2504:         return '';
 2505:     }
 2506:     Apache::lonhelper::parmwizfinal->new();
 2507: }
 2508: 
 2509: # Renders a form that, when submitted, will form the input to lonparmset.pm
 2510: sub render {
 2511:     my $self = shift;
 2512:     my $vars = $helper->{VARS};
 2513: 
 2514:     # FIXME: Unify my designators with the standard ones
 2515:     my %dateTypeHash = ('open_date' => "Opening Date",
 2516:                         'due_date' => "Due Date",
 2517:                         'answer_date' => "Answer Date");
 2518:     my %parmTypeHash = ('open_date' => "0_opendate",
 2519:                         'due_date' => "0_duedate",
 2520:                         'answer_date' => "0_answerdate");
 2521:     
 2522:     my $affectedResourceId = "";
 2523:     my $parm_name = $parmTypeHash{$vars->{ACTION_TYPE}};
 2524:     my $level = "";
 2525:     my $resourceString;
 2526:     my $symb;
 2527:     my $paramlevel;
 2528: 
 2529:     # Print the granularity, depending on the action
 2530:     if ($vars->{GRANULARITY} eq 'whole_course') {
 2531:         $resourceString .= '<li>for <b>all resources in the course</b></li>';
 2532:         $level = 9; # general course, see lonparmset.pm perldoc
 2533:         $affectedResourceId = "0.0";
 2534:         $symb = 'a';
 2535:         $paramlevel = 'general';
 2536:     } elsif ($vars->{GRANULARITY} eq 'map') {
 2537:         my $navmap = Apache::lonnavmaps::navmap->new(
 2538:                            $ENV{"request.course.fn"}.".db",
 2539:                            $ENV{"request.course.fn"}."_parms.db", 0, 0);
 2540:         my $res = $navmap->getById($vars->{RESOURCE_ID});
 2541:         my $title = $res->compTitle();
 2542:         $symb = $res->symb();
 2543:         $navmap->untieHashes();
 2544:         $resourceString .= "<li>for the map named <b>$title</b></li>";
 2545:         $level = 8;
 2546:         $affectedResourceId = $vars->{RESOURCE_ID};
 2547:         $paramlevel = 'map';
 2548:     } else {
 2549:         my $navmap = Apache::lonnavmaps::navmap->new(
 2550:                            $ENV{"request.course.fn"}.".db",
 2551:                            $ENV{"request.course.fn"}."_parms.db", 0, 0);
 2552:         my $res = $navmap->getById($vars->{RESOURCE_ID});
 2553:         $symb = $res->symb();
 2554:         my $title = $res->compTitle();
 2555:         $navmap->untieHashes();
 2556:         $resourceString .= "<li>for the resource named <b>$title</b></li>";
 2557:         $level = 7;
 2558:         $affectedResourceId = $vars->{RESOURCE_ID};
 2559:         $paramlevel = 'full';
 2560:     }
 2561: 
 2562:     my $result = "<form name='helpform' method='get' action='/adm/parmset#$affectedResourceId&$parm_name&$level'>\n";
 2563:     $result .= '<p>Confirm that this information is correct, then click &quot;Finish Wizard&quot; to complete setting the parameter.<ul>';
 2564:     
 2565:     # Print the type of manipulation:
 2566:     $result .= '<li>Setting the <b>' . $dateTypeHash{$vars->{ACTION_TYPE}}
 2567:                . "</b></li>\n";
 2568:     if ($vars->{ACTION_TYPE} eq 'due_date' || 
 2569:         $vars->{ACTION_TYPE} eq 'answer_date') {
 2570:         # for due dates, we default to "date end" type entries
 2571:         $result .= "<input type='hidden' name='recent_date_end' " .
 2572:             "value='" . $vars->{PARM_DATE} . "' />\n";
 2573:         $result .= "<input type='hidden' name='pres_value' " . 
 2574:             "value='" . $vars->{PARM_DATE} . "' />\n";
 2575:         $result .= "<input type='hidden' name='pres_type' " .
 2576:             "value='date_end' />\n";
 2577:     } elsif ($vars->{ACTION_TYPE} eq 'open_date') {
 2578:         $result .= "<input type='hidden' name='recent_date_start' ".
 2579:             "value='" . $vars->{PARM_DATE} . "' />\n";
 2580:         $result .= "<input type='hidden' name='pres_value' " .
 2581:             "value='" . $vars->{PARM_DATE} . "' />\n";
 2582:         $result .= "<input type='hidden' name='pres_type' " .
 2583:             "value='date_start' />\n";
 2584:     } 
 2585: 
 2586:     $result .= $resourceString;
 2587:     
 2588:     # Print targets
 2589:     if ($vars->{TARGETS} eq 'course') {
 2590:         $result .= '<li>for <b>all students in course</b></li>';
 2591:     } elsif ($vars->{TARGETS} eq 'section') {
 2592:         my $section = $vars->{SECTION_NAME};
 2593:         $result .= "<li>for section <b>$section</b></li>";
 2594:         $level -= 3;
 2595:         $result .= "<input type='hidden' name='csec' value='" .
 2596:             HTML::Entities::encode($section) . "' />\n";
 2597:     } else {
 2598:         # FIXME: This is probably wasteful! Store the name!
 2599:         my $classlist = Apache::loncoursedata::get_classlist();
 2600:         my $username = $vars->{USER_NAME};
 2601:         # Chop off everything after the last colon (section)
 2602:         $username = substr($username, 0, rindex($username, ':'));
 2603:         my $name = $classlist->{$username}->[6];
 2604:         $result .= "<li>for <b>$name</b></li>";
 2605:         $level -= 6;
 2606:         my ($uname, $udom) = split /:/, $vars->{USER_NAME};
 2607:         $result .= "<input type='hidden' name='uname' value='".
 2608:             HTML::Entities::encode($uname) . "' />\n";
 2609:         $result .= "<input type='hidden' name='udom' value='".
 2610:             HTML::Entities::encode($udom) . "' />\n";
 2611:     }
 2612: 
 2613:     # Print value
 2614:     $result .= "<li>to <b>" . ctime($vars->{PARM_DATE}) . "</b> (" .
 2615:         Apache::lonnavmaps::timeToHumanString($vars->{PARM_DATE}) 
 2616:         . ")</li>\n";
 2617: 
 2618:     # print pres_marker
 2619:     $result .= "\n<input type='hidden' name='pres_marker'" .
 2620:         " value='$affectedResourceId&$parm_name&$level' />\n";
 2621:     
 2622:     # Make the table appear
 2623:     $result .= "\n<input type='hidden' value='true' name='prevvisit' />";
 2624:     $result .= "\n<input type='hidden' value='all' name='pschp' />";
 2625:     $result .= "\n<input type='hidden' value='$symb' name='pssymb' />";
 2626:     $result .= "\n<input type='hidden' value='$paramlevel' name='parmlev' />";
 2627: 
 2628:     $result .= "<br /><br /><center><input type='submit' value='Finish Helper' /></center></form>\n";
 2629: 
 2630:     return $result;
 2631: }
 2632:     
 2633: sub overrideForm {
 2634:     return 1;
 2635: }
 2636: 
 2637: 1;
 2638: 
 2639: __END__
 2640: