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[LON-CAPA] /
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lonhelper.pm
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Wed May 14 20:16:56 2003 UTC (21 years, 1 month ago) by
bowersj2
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For bug 1306 and some other things.
When filtering resources out of the nav maps, such as in printing when
the user is allowed to select just problems out of the course, it is
common that there are folders that contain no problems. Thus, before
this patch those folders just sat there, empty and open, which is a
visually confusing UI state, even to me, so I imagine the users would
be even worse off.
The navmaps part of this patch allows you to specify a parameter such
that empty maps should be suppressed, so they don't display and confuse
the user. The lonhelper part of this patch passes that parameter through
for resource elements. The lonprintout part of this patch turns
that feature on for "print problems from this course", so that empty
folders no longer show up there.
This turned out to require pleasently little code in lonnavmaps, by
putting it in the right place. The real functionality is all in about 20
lines (without comments).
1: # The LearningOnline Network with CAPA
2: # .helper XML handler to implement the LON-CAPA helper
3: #
4: # $Id: lonhelper.pm,v 1.29 2003/05/14 20:16:56 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".
57:
58: =head2 State tags
59:
60: State tags are required to have an attribute "name", which is the symbolic
61: name of the state and will not be directly seen by the user. The helper is
62: required to have one state named "START", which is the state the helper
63: will start with. By convention, this state should clearly describe what
64: the helper will do for the user, and may also include the first information
65: entry the user needs to do for the helper.
66:
67: State tags are also required to have an attribute "title", which is the
68: human name of the state, and will be displayed as the header on top of
69: the screen for the user.
70:
71: =head2 Example Helper Skeleton
72:
73: An example of the tags so far:
74:
75: <helper title="Example Helper">
76: <state name="START" title="Demonstrating the Example Helper">
77: <!-- notice this is the START state the wizard requires -->
78: </state>
79: <state name="GET_NAME" title="Enter Student Name">
80: </state>
81: </helper>
82:
83: Of course this does nothing. In order for the wizard to do something, it is
84: necessary to put actual elements into the wizard. Documentation for each
85: of these elements follows.
86:
87: =head2 Creating a Helper With Code, Not XML
88:
89: In some situations, such as the printing wizard (see lonprintout.pm),
90: writing the helper in XML would be too complicated, because of scope
91: issues or the fact that the code actually outweighs the XML. It is
92: possible to create a helper via code, though it is a little odd.
93:
94: Creating a helper via code is more like issuing commands to create
95: a helper then normal code writing. For instance, elements will automatically
96: be added to the last state created, so it's important to create the
97: states in the correct order.
98:
99: First, create a new helper:
100:
101: use Apache::lonhelper;
102:
103: my $helper = Apache::lonhelper::new->("Helper Title");
104:
105: Next you'll need to manually add states to the helper:
106:
107: Apache::lonhelper::state->new("STATE_NAME", "State's Human Title");
108:
109: You don't need to save a reference to it because all elements up until
110: the next state creation will automatically be added to this state.
111:
112: Elements are created by populating the $paramHash in
113: Apache::lonhelper::paramhash. To prevent namespace issues, retrieve
114: a reference to that has with getParamHash:
115:
116: my $paramHash = Apache::lonhelper::getParamHash();
117:
118: You will need to do this for each state you create.
119:
120: Populate the $paramHash with the parameters for the element you wish
121: to add next; the easiest way to find out what those entries are is
122: to read the code. Some common ones are 'variable' to record the variable
123: to store the results in, and NEXTSTATE to record a next state transition.
124:
125: Then create your element:
126:
127: $paramHash->{MESSAGETEXT} = "This is a message.";
128: Apache::lonhelper::message->new();
129:
130: The creation will take the $paramHash and bless it into a
131: Apache::lonhelper::message object. To create the next element, you need
132: to get a reference to the new, empty $paramHash:
133:
134: $paramHash = Apache::lonhelper::getParamHash();
135:
136: and you can repeat creating elements that way. You can add states
137: and elements as needed.
138:
139: See lonprintout.pm, subroutine printHelper for an example of this, where
140: we dynamically add some states to prevent security problems, for instance.
141:
142: Normally the machinery in the XML format is sufficient; dynamically
143: adding states can easily be done by wrapping the state in a <condition>
144: tag. This should only be used when the code dominates the XML content,
145: the code is so complicated that it is difficult to get access to
146: all of the information you need because of scoping issues, or so much
147: of the information used is persistent because would-be <exec> or
148: <eval> blocks that using the {DATA} mechanism results in hard-to-read
149: and -maintain code.
150:
151: It is possible to do some of the work with an XML fragment parsed by
152: lonxml; again, see lonprintout.pm for an example. In that case it is
153: imperative that you call B<Apache::lonhelper::registerHelperTags()>
154: before parsing XML fragments and B<Apache::lonhelper::unregisterHelperTags()>
155: when you are done. See lonprintout.pm for examples of this usage in the
156: printHelper subroutine.
157:
158: =cut
159:
160: package Apache::lonhelper;
161: use Apache::Constants qw(:common);
162: use Apache::File;
163: use Apache::lonxml;
164:
165: # Register all the tags with the helper, so the helper can
166: # push and pop them
167:
168: my @helperTags;
169:
170: sub register {
171: my ($namespace, @tags) = @_;
172:
173: for my $tag (@tags) {
174: push @helperTags, [$namespace, $tag];
175: }
176: }
177:
178: BEGIN {
179: Apache::lonxml::register('Apache::lonhelper',
180: ('helper'));
181: register('Apache::lonhelper', ('state'));
182: }
183:
184: # Since all helpers are only three levels deep (helper tag, state tag,
185: # substate type), it's easier and more readble to explicitly track
186: # those three things directly, rather then futz with the tag stack
187: # every time.
188: my $helper;
189: my $state;
190: my $substate;
191: # To collect parameters, the contents of the subtags are collected
192: # into this paramHash, then passed to the element object when the
193: # end of the element tag is located.
194: my $paramHash;
195:
196: # Note from Jeremy 5-8-2003: It is *vital* that the real handler be called
197: # as a subroutine from the handler, or very mysterious things might happen.
198: # I don't know exactly why, but it seems that the scope where the Apache
199: # server enters the perl handler is treated differently from the rest of
200: # the handler. This also seems to manifest itself in the debugger as entering
201: # the perl handler in seemingly random places (sometimes it starts in the
202: # compiling phase, sometimes in the handler execution phase where it runs
203: # the code and stepping into the "1;" the module ends with goes into the handler,
204: # sometimes starting directly with the handler); I think the cause is related.
205: # In the debugger, this means that breakpoints are ignored until you step into
206: # a function and get out of what must be a "faked up scope" in the Apache->
207: # mod_perl connection. In this code, it was manifesting itself in the existence
208: # of two seperate file-scoped $helper variables, one set to the value of the
209: # helper in the helper constructor, and one referenced by the handler on the
210: # "$helper->process()" line. The second was therefore never set, and was still
211: # undefined when I tried to call process on it.
212: # By pushing the "real handler" down into the "real scope", everybody except the
213: # actual handler function directly below this comment gets the same $helper and
214: # everybody is happy.
215: # The upshot of all of this is that for safety when a handler is using
216: # file-scoped variables in LON-CAPA, the handler should be pushed down one
217: # call level, as I do here, to ensure that the top-level handler function does
218: # not get a different file scope from the rest of the code.
219: sub handler {
220: my $r = shift;
221: return real_handler($r);
222: }
223:
224: # For debugging purposes, one can send a second parameter into this
225: # function, the 'uri' of the helper you wish to have rendered, and
226: # call this from other handlers.
227: sub real_handler {
228: my $r = shift;
229: my $uri = shift;
230: if (!defined($uri)) { $uri = $r->uri(); }
231: $ENV{'request.uri'} = $uri;
232: my $filename = '/home/httpd/html' . $uri;
233: my $fh = Apache::File->new($filename);
234: my $file;
235: read $fh, $file, 100000000;
236:
237:
238: # Send header, don't cache this page
239: if ($r->header_only) {
240: if ($ENV{'browser.mathml'}) {
241: $r->content_type('text/xml');
242: } else {
243: $r->content_type('text/html');
244: }
245: $r->send_http_header;
246: return OK;
247: }
248: if ($ENV{'browser.mathml'}) {
249: $r->content_type('text/xml');
250: } else {
251: $r->content_type('text/html');
252: }
253: $r->send_http_header;
254: $r->rflush();
255:
256: # Discard result, we just want the objects that get created by the
257: # xml parsing
258: &Apache::lonxml::xmlparse($r, 'helper', $file);
259:
260: $helper->process();
261:
262: $r->print($helper->display());
263: return OK;
264: }
265:
266: sub registerHelperTags {
267: for my $tagList (@helperTags) {
268: Apache::lonxml::register($tagList->[0], $tagList->[1]);
269: }
270: }
271:
272: sub unregisterHelperTags {
273: for my $tagList (@helperTags) {
274: Apache::lonxml::deregister($tagList->[0], $tagList->[1]);
275: }
276: }
277:
278: sub start_helper {
279: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
280:
281: if ($target ne 'helper') {
282: return '';
283: }
284:
285: registerHelperTags();
286:
287: Apache::lonhelper::helper->new($token->[2]{'title'});
288: return '';
289: }
290:
291: sub end_helper {
292: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
293:
294: if ($target ne 'helper') {
295: return '';
296: }
297:
298: unregisterHelperTags();
299:
300: return '';
301: }
302:
303: sub start_state {
304: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
305:
306: if ($target ne 'helper') {
307: return '';
308: }
309:
310: Apache::lonhelper::state->new($token->[2]{'name'},
311: $token->[2]{'title'});
312: return '';
313: }
314:
315: # Use this to get the param hash from other files.
316: sub getParamHash {
317: return $paramHash;
318: }
319:
320: # Use this to get the helper, if implementing elements in other files
321: # (like lonprintout.pm)
322: sub getHelper {
323: return $helper;
324: }
325:
326: # don't need this, so ignore it
327: sub end_state {
328: return '';
329: }
330:
331: 1;
332:
333: package Apache::lonhelper::helper;
334:
335: use Digest::MD5 qw(md5_hex);
336: use HTML::Entities;
337: use Apache::loncommon;
338: use Apache::File;
339:
340: sub new {
341: my $proto = shift;
342: my $class = ref($proto) || $proto;
343: my $self = {};
344:
345: $self->{TITLE} = shift;
346:
347: # If there is a state from the previous form, use that. If there is no
348: # state, use the start state parameter.
349: if (defined $ENV{"form.CURRENT_STATE"})
350: {
351: $self->{STATE} = $ENV{"form.CURRENT_STATE"};
352: }
353: else
354: {
355: $self->{STATE} = "START";
356: }
357:
358: $self->{TOKEN} = $ENV{'form.TOKEN'};
359: # If a token was passed, we load that in. Otherwise, we need to create a
360: # new storage file
361: # Tried to use standard Tie'd hashes, but you can't seem to take a
362: # reference to a tied hash and write to it. I'd call that a wart.
363: if ($self->{TOKEN}) {
364: # Validate the token before trusting it
365: if ($self->{TOKEN} !~ /^[a-f0-9]{32}$/) {
366: # Not legit. Return nothing and let all hell break loose.
367: # User shouldn't be doing that!
368: return undef;
369: }
370:
371: # Get the hash.
372: $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN}); # Note the token is not the literal file
373:
374: my $file = Apache::File->new($self->{FILENAME});
375: my $contents = <$file>;
376:
377: # Now load in the contents
378: for my $value (split (/&/, $contents)) {
379: my ($name, $value) = split(/=/, $value);
380: $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
381: $self->{VARS}->{$name} = $value;
382: }
383:
384: $file->close();
385: } else {
386: # Only valid if we're just starting.
387: if ($self->{STATE} ne 'START') {
388: return undef;
389: }
390: # Must create the storage
391: $self->{TOKEN} = md5_hex($ENV{'user.name'} . $ENV{'user.domain'} .
392: time() . rand());
393: $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN});
394: }
395:
396: # OK, we now have our persistent storage.
397:
398: if (defined $ENV{"form.RETURN_PAGE"})
399: {
400: $self->{RETURN_PAGE} = $ENV{"form.RETURN_PAGE"};
401: }
402: else
403: {
404: $self->{RETURN_PAGE} = $ENV{REFERER};
405: }
406:
407: $self->{STATES} = {};
408: $self->{DONE} = 0;
409:
410: # Used by various helpers for various things; see lonparm.helper
411: # for an example.
412: $self->{DATA} = {};
413:
414: $helper = $self;
415:
416: # Establish the $paramHash
417: $paramHash = {};
418:
419: bless($self, $class);
420: return $self;
421: }
422:
423: # Private function; returns a string to construct the hidden fields
424: # necessary to have the helper track state.
425: sub _saveVars {
426: my $self = shift;
427: my $result = "";
428: $result .= '<input type="hidden" name="CURRENT_STATE" value="' .
429: HTML::Entities::encode($self->{STATE}) . "\" />\n";
430: $result .= '<input type="hidden" name="TOKEN" value="' .
431: $self->{TOKEN} . "\" />\n";
432: $result .= '<input type="hidden" name="RETURN_PAGE" value="' .
433: HTML::Entities::encode($self->{RETURN_PAGE}) . "\" />\n";
434:
435: return $result;
436: }
437:
438: # Private function: Create the querystring-like representation of the stored
439: # data to write to disk.
440: sub _varsInFile {
441: my $self = shift;
442: my @vars = ();
443: for my $key (keys %{$self->{VARS}}) {
444: push @vars, &Apache::lonnet::escape($key) . '=' .
445: &Apache::lonnet::escape($self->{VARS}->{$key});
446: }
447: return join ('&', @vars);
448: }
449:
450: # Use this to declare variables.
451: # FIXME: Document this
452: sub declareVar {
453: my $self = shift;
454: my $var = shift;
455:
456: if (!defined($self->{VARS}->{$var})) {
457: $self->{VARS}->{$var} = '';
458: }
459:
460: my $envname = 'form.' . $var . '.forminput';
461: if (defined($ENV{$envname})) {
462: if (ref($ENV{$envname})) {
463: $self->{VARS}->{$var} = join('|||', @{$ENV{$envname}});
464: } else {
465: $self->{VARS}->{$var} = $ENV{$envname};
466: }
467: }
468: }
469:
470: sub changeState {
471: my $self = shift;
472: $self->{STATE} = shift;
473: }
474:
475: sub registerState {
476: my $self = shift;
477: my $state = shift;
478:
479: my $stateName = $state->name();
480: $self->{STATES}{$stateName} = $state;
481: }
482:
483: sub process {
484: my $self = shift;
485:
486: # Phase 1: Post processing for state of previous screen (which is actually
487: # the "current state" in terms of the helper variables), if it wasn't the
488: # beginning state.
489: if ($self->{STATE} ne "START" || $ENV{"form.SUBMIT"} eq "Next ->") {
490: my $prevState = $self->{STATES}{$self->{STATE}};
491: $prevState->postprocess();
492: }
493:
494: # Note, to handle errors in a state's input that a user must correct,
495: # do not transition in the postprocess, and force the user to correct
496: # the error.
497:
498: # Phase 2: Preprocess current state
499: my $startState = $self->{STATE};
500: my $state = $self->{STATES}->{$startState};
501:
502: # For debugging, print something here to determine if you're going
503: # to an undefined state.
504: if (!defined($state)) {
505: return;
506: }
507: $state->preprocess();
508:
509: # Phase 3: While the current state is different from the previous state,
510: # keep processing.
511: while ( $startState ne $self->{STATE} &&
512: defined($self->{STATES}->{$self->{STATE}}) )
513: {
514: $startState = $self->{STATE};
515: $state = $self->{STATES}->{$startState};
516: $state->preprocess();
517: }
518:
519: return;
520: }
521:
522: # 1: Do the post processing for the previous state.
523: # 2: Do the preprocessing for the current state.
524: # 3: Check to see if state changed, if so, postprocess current and move to next.
525: # Repeat until state stays stable.
526: # 4: Render the current state to the screen as an HTML page.
527: sub display {
528: my $self = shift;
529:
530: my $state = $self->{STATES}{$self->{STATE}};
531:
532: my $result = "";
533:
534: if (!defined($state)) {
535: $result = "<font color='#ff0000'>Error: state '$state' not defined!</font>";
536: return $result;
537: }
538:
539: # Phase 4: Display.
540: my $stateTitle = $state->title();
541: my $bodytag = &Apache::loncommon::bodytag("$self->{TITLE}",'','');
542:
543: $result .= <<HEADER;
544: <html>
545: <head>
546: <title>LON-CAPA Helper: $self->{TITLE}</title>
547: </head>
548: $bodytag
549: HEADER
550: if (!$state->overrideForm()) { $result.="<form name='helpform' method='POST'>"; }
551: $result .= <<HEADER;
552: <table border="0"><tr><td>
553: <h2><i>$stateTitle</i></h2>
554: HEADER
555:
556: if (!$state->overrideForm()) {
557: $result .= $self->_saveVars();
558: }
559: $result .= $state->render() . "<p> </p>";
560:
561: if (!$state->overrideForm()) {
562: $result .= '<center>';
563: if ($self->{STATE} ne $self->{START_STATE}) {
564: #$result .= '<input name="SUBMIT" type="submit" value="<- Previous" /> ';
565: }
566: if ($self->{DONE}) {
567: my $returnPage = $self->{RETURN_PAGE};
568: $result .= "<a href=\"$returnPage\">End Helper</a>";
569: }
570: else {
571: $result .= '<input name="back" type="button" ';
572: $result .= 'value="<- Previous" onclick="history.go(-1)" /> ';
573: $result .= '<input name="SUBMIT" type="submit" value="Next ->" />';
574: }
575: $result .= "</center>\n";
576: }
577:
578: #foreach my $key (keys %{$self->{VARS}}) {
579: # $result .= "|$key| -> " . $self->{VARS}->{$key} . "<br />";
580: #}
581:
582: $result .= <<FOOTER;
583: </td>
584: </tr>
585: </table>
586: </form>
587: </body>
588: </html>
589: FOOTER
590:
591: # Handle writing out the vars to the file
592: my $file = Apache::File->new('>'.$self->{FILENAME});
593: print $file $self->_varsInFile();
594:
595: return $result;
596: }
597:
598: 1;
599:
600: package Apache::lonhelper::state;
601:
602: # States bundle things together and are responsible for compositing the
603: # various elements together. It is not generally necessary for users to
604: # use the state object directly, so it is not perldoc'ed.
605:
606: # Basically, all the states do is pass calls to the elements and aggregate
607: # the results.
608:
609: sub new {
610: my $proto = shift;
611: my $class = ref($proto) || $proto;
612: my $self = {};
613:
614: $self->{NAME} = shift;
615: $self->{TITLE} = shift;
616: $self->{ELEMENTS} = [];
617:
618: bless($self, $class);
619:
620: $helper->registerState($self);
621:
622: $state = $self;
623:
624: return $self;
625: }
626:
627: sub name {
628: my $self = shift;
629: return $self->{NAME};
630: }
631:
632: sub title {
633: my $self = shift;
634: return $self->{TITLE};
635: }
636:
637: sub preprocess {
638: my $self = shift;
639: for my $element (@{$self->{ELEMENTS}}) {
640: $element->preprocess();
641: }
642: }
643:
644: # FIXME: Document that all postprocesses must return a true value or
645: # the state transition will be overridden
646: sub postprocess {
647: my $self = shift;
648:
649: # Save the state so we can roll it back if we need to.
650: my $originalState = $helper->{STATE};
651: my $everythingSuccessful = 1;
652:
653: for my $element (@{$self->{ELEMENTS}}) {
654: my $result = $element->postprocess();
655: if (!$result) { $everythingSuccessful = 0; }
656: }
657:
658: # If not all the postprocesses were successful, override
659: # any state transitions that may have occurred. It is the
660: # responsibility of the states to make sure they have
661: # error handling in that case.
662: if (!$everythingSuccessful) {
663: $helper->{STATE} = $originalState;
664: }
665: }
666:
667: # Override the form if any element wants to.
668: # two elements overriding the form will make a mess, but that should
669: # be considered helper author error ;-)
670: sub overrideForm {
671: my $self = shift;
672: for my $element (@{$self->{ELEMENTS}}) {
673: if ($element->overrideForm()) {
674: return 1;
675: }
676: }
677: return 0;
678: }
679:
680: sub addElement {
681: my $self = shift;
682: my $element = shift;
683:
684: push @{$self->{ELEMENTS}}, $element;
685: }
686:
687: use Data::Dumper;
688: sub render {
689: my $self = shift;
690: my @results = ();
691:
692: for my $element (@{$self->{ELEMENTS}}) {
693: push @results, $element->render();
694: }
695:
696: return join("\n", @results);
697: }
698:
699: 1;
700:
701: package Apache::lonhelper::element;
702: # Support code for elements
703:
704: =pod
705:
706: =head2 Element Base Class
707:
708: The Apache::lonhelper::element base class provides support for elements
709: and defines some generally useful tags for use in elements.
710:
711: B<finalcode tag>
712:
713: Each element can contain a "finalcode" tag that, when the special FINAL
714: helper state is used, will be executed, surrounded by "sub { my $helper = shift;"
715: and "}". It is expected to return a string describing what it did, which
716: may be an empty string. See course initialization helper for an example. This is
717: generally intended for helpers like the course initialization helper, which consist
718: of several panels, each of which is performing some sort of bite-sized functionality.
719:
720: B<defaultvalue tag>
721:
722: Each element that accepts user input can contain a "defaultvalue" tag that,
723: when surrounded by "sub { my $helper = shift; my $state = shift; " and "}",
724: will form a subroutine that when called will provide a default value for
725: the element. How this value is interpreted by the element is specific to
726: the element itself, and possibly the settings the element has (such as
727: multichoice vs. single choice for <choices> tags).
728:
729: This is also intended for things like the course initialization wizard, where the
730: user is setting various parameters. By correctly grabbing current settings
731: and including them into the helper, it allows the user to come back to the
732: helper later and re-execute it, without needing to worry about overwriting
733: some setting accidentally.
734:
735: Again, see the course initialization helper for examples.
736:
737: =cut
738:
739: BEGIN {
740: &Apache::lonhelper::register('Apache::lonhelper::element',
741: ('nextstate', 'finalcode',
742: 'defaultvalue'));
743: }
744:
745: # Because we use the param hash, this is often a sufficent
746: # constructor
747: sub new {
748: my $proto = shift;
749: my $class = ref($proto) || $proto;
750: my $self = $paramHash;
751: bless($self, $class);
752:
753: $self->{PARAMS} = $paramHash;
754: $self->{STATE} = $state;
755: $state->addElement($self);
756:
757: # Ensure param hash is not reused
758: $paramHash = {};
759:
760: return $self;
761: }
762:
763: sub start_nextstate {
764: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
765:
766: if ($target ne 'helper') {
767: return '';
768: }
769:
770: $paramHash->{NEXTSTATE} = &Apache::lonxml::get_all_text('/nextstate',
771: $parser);
772: return '';
773: }
774:
775: sub end_nextstate { return ''; }
776:
777: sub start_finalcode {
778: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
779:
780: if ($target ne 'helper') {
781: return '';
782: }
783:
784: $paramHash->{FINAL_CODE} = &Apache::lonxml::get_all_text('/finalcode',
785: $parser);
786: return '';
787: }
788:
789: sub end_finalcode { return ''; }
790:
791: sub start_defaultvalue {
792: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
793:
794: if ($target ne 'helper') {
795: return '';
796: }
797:
798: $paramHash->{DEFAULT_VALUE} = &Apache::lonxml::get_all_text('/defaultvalue',
799: $parser);
800: $paramHash->{DEFAULT_VALUE} = 'sub { my $helper = shift; my $state = shift;' .
801: $paramHash->{DEFAULT_VALUE} . '}';
802: return '';
803: }
804:
805: sub end_defaultvalue { return ''; }
806:
807: sub preprocess {
808: return 1;
809: }
810:
811: sub postprocess {
812: return 1;
813: }
814:
815: sub render {
816: return '';
817: }
818:
819: sub overrideForm {
820: return 0;
821: }
822:
823: 1;
824:
825: package Apache::lonhelper::message;
826:
827: =pod
828:
829: =head2 Element: message
830:
831: Message elements display the contents of their <message_text> tags, and
832: transition directly to the state in the <nextstate> tag. Example:
833:
834: <message>
835: <nextstate>GET_NAME</nextstate>
836: <message_text>This is the <b>message</b> the user will see,
837: <i>HTML allowed</i>.</message_text>
838: </message>
839:
840: This will display the HTML message and transition to the <nextstate> if
841: given. The HTML will be directly inserted into the helper, so if you don't
842: want text to run together, you'll need to manually wrap the <message_text>
843: in <p> tags, or whatever is appropriate for your HTML.
844:
845: Message tags do not add in whitespace, so if you want it, you'll need to add
846: it into states. This is done so you can inline some elements, such as
847: the <date> element, right between two messages, giving the appearence that
848: the <date> element appears inline. (Note the elements can not be embedded
849: within each other.)
850:
851: This is also a good template for creating your own new states, as it has
852: very little code beyond the state template.
853:
854: =cut
855:
856: no strict;
857: @ISA = ("Apache::lonhelper::element");
858: use strict;
859:
860: BEGIN {
861: &Apache::lonhelper::register('Apache::lonhelper::message',
862: ('message'));
863: }
864:
865: sub new {
866: my $ref = Apache::lonhelper::element->new();
867: bless($ref);
868: }
869:
870: # CONSTRUCTION: Construct the message element from the XML
871: sub start_message {
872: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
873:
874: if ($target ne 'helper') {
875: return '';
876: }
877:
878: $paramHash->{MESSAGE_TEXT} = &Apache::lonxml::get_all_text('/message',
879: $parser);
880:
881: if (defined($token->[2]{'nextstate'})) {
882: $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
883: }
884: return '';
885: }
886:
887: sub end_message {
888: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
889:
890: if ($target ne 'helper') {
891: return '';
892: }
893: Apache::lonhelper::message->new();
894: return '';
895: }
896:
897: sub render {
898: my $self = shift;
899:
900: return $self->{MESSAGE_TEXT};
901: }
902: # If a NEXTSTATE was given, switch to it
903: sub postprocess {
904: my $self = shift;
905: if (defined($self->{NEXTSTATE})) {
906: $helper->changeState($self->{NEXTSTATE});
907: }
908:
909: return 1;
910: }
911: 1;
912:
913: package Apache::lonhelper::choices;
914:
915: =pod
916:
917: =head2 Element: choices
918:
919: Choice states provide a single choice to the user as a text selection box.
920: A "choice" is two pieces of text, one which will be displayed to the user
921: (the "human" value), and one which will be passed back to the program
922: (the "computer" value). For instance, a human may choose from a list of
923: resources on disk by title, while your program wants the file name.
924:
925: <choices> takes an attribute "variable" to control which helper variable
926: the result is stored in.
927:
928: <choices> takes an attribute "multichoice" which, if set to a true
929: value, will allow the user to select multiple choices.
930:
931: <choices> takes an attribute "allowempty" which, if set to a true
932: value, will allow the user to select none of the choices without raising
933: an error message.
934:
935: B<SUB-TAGS>
936:
937: <choices> can have the following subtags:
938:
939: =over 4
940:
941: =item * <nextstate>state_name</nextstate>: If given, this will cause the
942: choice element to transition to the given state after executing. If
943: this is used, do not pass nextstates to the <choice> tag.
944:
945: =item * <choice />: If the choices are static,
946: this element will allow you to specify them. Each choice
947: contains attribute, "computer", as described above. The
948: content of the tag will be used as the human label.
949: For example,
950: <choice computer='234-12-7312'>Bobby McDormik</choice>.
951:
952: <choice> can take a parameter "eval", which if set to
953: a true value, will cause the contents of the tag to be
954: evaluated as it would be in an <eval> tag; see <eval> tag
955: below.
956:
957: <choice> may optionally contain a 'nextstate' attribute, which
958: will be the state transisitoned to if the choice is made, if
959: the choice is not multichoice.
960:
961: =back
962:
963: To create the choices programmatically, either wrap the choices in
964: <condition> tags (prefered), or use an <exec> block inside the <choice>
965: tag. Store the choices in $state->{CHOICES}, which is a list of list
966: references, where each list has three strings. The first is the human
967: name, the second is the computer name. and the third is the option
968: next state. For example:
969:
970: <exec>
971: for (my $i = 65; $i < 65 + 26; $i++) {
972: push @{$state->{CHOICES}}, [chr($i), $i, 'next'];
973: }
974: </exec>
975:
976: This will allow the user to select from the letters A-Z (in ASCII), while
977: passing the ASCII value back into the helper variables, and the state
978: will in all cases transition to 'next'.
979:
980: You can mix and match methods of creating choices, as long as you always
981: "push" onto the choice list, rather then wiping it out. (You can even
982: remove choices programmatically, but that would probably be bad form.)
983:
984: B<defaultvalue support>
985:
986: Choices supports default values both in multichoice and single choice mode.
987: In single choice mode, have the defaultvalue tag's function return the
988: computer value of the box you want checked. If the function returns a value
989: that does not correspond to any of the choices, the default behavior of selecting
990: the first choice will be preserved.
991:
992: For multichoice, return a string with the computer values you want checked,
993: delimited by triple pipes. Note this matches how the result of the <choices>
994: tag is stored in the {VARS} hash.
995:
996: =cut
997:
998: no strict;
999: @ISA = ("Apache::lonhelper::element");
1000: use strict;
1001:
1002: BEGIN {
1003: &Apache::lonhelper::register('Apache::lonhelper::choices',
1004: ('choice', 'choices'));
1005: }
1006:
1007: sub new {
1008: my $ref = Apache::lonhelper::element->new();
1009: bless($ref);
1010: }
1011:
1012: # CONSTRUCTION: Construct the message element from the XML
1013: sub start_choices {
1014: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1015:
1016: if ($target ne 'helper') {
1017: return '';
1018: }
1019:
1020: # Need to initialize the choices list, so everything can assume it exists
1021: $paramHash->{'variable'} = $token->[2]{'variable'} if (!defined($paramHash->{'variable'}));
1022: $helper->declareVar($paramHash->{'variable'});
1023: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1024: $paramHash->{'allowempty'} = $token->[2]{'allowempty'};
1025: $paramHash->{CHOICES} = [];
1026: return '';
1027: }
1028:
1029: sub end_choices {
1030: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1031:
1032: if ($target ne 'helper') {
1033: return '';
1034: }
1035: Apache::lonhelper::choices->new();
1036: return '';
1037: }
1038:
1039: sub start_choice {
1040: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1041:
1042: if ($target ne 'helper') {
1043: return '';
1044: }
1045:
1046: my $computer = $token->[2]{'computer'};
1047: my $human = &Apache::lonxml::get_all_text('/choice',
1048: $parser);
1049: my $nextstate = $token->[2]{'nextstate'};
1050: my $evalFlag = $token->[2]{'eval'};
1051: push @{$paramHash->{CHOICES}}, [$human, $computer, $nextstate,
1052: $evalFlag];
1053: return '';
1054: }
1055:
1056: sub end_choice {
1057: return '';
1058: }
1059:
1060: sub render {
1061: # START HERE: Replace this with correct choices code.
1062: my $self = shift;
1063: my $var = $self->{'variable'};
1064: my $buttons = '';
1065: my $result = '';
1066:
1067: if ($self->{'multichoice'}) {
1068: $result .= <<SCRIPT;
1069: <script>
1070: function checkall(value, checkName) {
1071: for (i=0; i<document.forms.helpform.elements.length; i++) {
1072: ele = document.forms.helpform.elements[i];
1073: if (ele.name == checkName + '.forminput') {
1074: document.forms.helpform.elements[i].checked=value;
1075: }
1076: }
1077: }
1078: </script>
1079: SCRIPT
1080: }
1081:
1082: # Only print "select all" and "unselect all" if there are five or
1083: # more choices; fewer then that and it looks silly.
1084: if ($self->{'multichoice'} && scalar(@{$self->{CHOICES}}) > 4) {
1085: $buttons = <<BUTTONS;
1086: <br />
1087: <input type="button" onclick="checkall(true, '$var')" value="Select All" />
1088: <input type="button" onclick="checkall(false, '$var')" value="Unselect All" />
1089: <br />
1090: BUTTONS
1091: }
1092:
1093: if (defined $self->{ERROR_MSG}) {
1094: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br />';
1095: }
1096:
1097: $result .= $buttons;
1098:
1099: $result .= "<table>\n\n";
1100:
1101: my %checkedChoices;
1102: my $checkedChoicesFunc;
1103:
1104: if (defined($self->{DEFAULT_VALUE})) {
1105: $checkedChoicesFunc = eval ($self->{DEFAULT_VALUE});
1106: die 'Error in default value code for variable ' .
1107: {'variable'} . ', Perl said:' . $@ if $@;
1108: } else {
1109: $checkedChoicesFunc = sub { return ''; };
1110: }
1111:
1112: # Process which choices should be checked.
1113: if ($self->{'multichoice'}) {
1114: for my $selectedChoice (split(/\|\|\|/, (&$checkedChoicesFunc($helper, $self)))) {
1115: $checkedChoices{$selectedChoice} = 1;
1116: }
1117: } else {
1118: # single choice
1119: my $selectedChoice = &$checkedChoicesFunc($helper, $self);
1120:
1121: my $foundChoice = 0;
1122:
1123: # check that the choice is in the list of choices.
1124: for my $choice (@{$self->{CHOICES}}) {
1125: if ($choice->[1] eq $selectedChoice) {
1126: $checkedChoices{$choice->[1]} = 1;
1127: $foundChoice = 1;
1128: }
1129: }
1130:
1131: # If we couldn't find the choice, pick the first one
1132: if (!$foundChoice) {
1133: $checkedChoices{$self->{CHOICES}->[0]->[1]} = 1;
1134: }
1135: }
1136:
1137: my $type = "radio";
1138: if ($self->{'multichoice'}) { $type = 'checkbox'; }
1139: foreach my $choice (@{$self->{CHOICES}}) {
1140: $result .= "<tr>\n<td width='20'> </td>\n";
1141: $result .= "<td valign='top'><input type='$type' name='$var.forminput'"
1142: . "' value='" .
1143: HTML::Entities::encode($choice->[1])
1144: . "'";
1145: if ($checkedChoices{$choice->[1]}) {
1146: $result .= " checked ";
1147: }
1148: my $choiceLabel = $choice->[0];
1149: if ($choice->[4]) { # if we need to evaluate this choice
1150: $choiceLabel = "sub { my $helper = shift; my $state = shift;" .
1151: $choiceLabel . "}";
1152: $choiceLabel = eval($choiceLabel);
1153: $choiceLabel = &$choiceLabel($helper, $self);
1154: }
1155: $result .= "/></td><td> " . $choiceLabel . "</td></tr>\n";
1156: }
1157: $result .= "</table>\n\n\n";
1158: $result .= $buttons;
1159:
1160: return $result;
1161: }
1162:
1163: # If a NEXTSTATE was given or a nextstate for this choice was
1164: # given, switch to it
1165: sub postprocess {
1166: my $self = shift;
1167: my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};
1168:
1169: if (!defined($chosenValue) && !$self->{'allowempty'}) {
1170: $self->{ERROR_MSG} = "You must choose one or more choices to" .
1171: " continue.";
1172: return 0;
1173: }
1174:
1175: if (ref($chosenValue)) {
1176: $helper->{VARS}->{$self->{'variable'}} = join('|||', @$chosenValue);
1177: }
1178:
1179: if (defined($self->{NEXTSTATE})) {
1180: $helper->changeState($self->{NEXTSTATE});
1181: }
1182:
1183: foreach my $choice (@{$self->{CHOICES}}) {
1184: if ($choice->[1] eq $chosenValue) {
1185: if (defined($choice->[2])) {
1186: $helper->changeState($choice->[2]);
1187: }
1188: }
1189: }
1190: return 1;
1191: }
1192: 1;
1193:
1194: package Apache::lonhelper::date;
1195:
1196: =pod
1197:
1198: =head2 Element: date
1199:
1200: Date elements allow the selection of a date with a drop down list.
1201:
1202: Date elements can take two attributes:
1203:
1204: =over 4
1205:
1206: =item * B<variable>: The name of the variable to store the chosen
1207: date in. Required.
1208:
1209: =item * B<hoursminutes>: If a true value, the date will show hours
1210: and minutes, as well as month/day/year. If false or missing,
1211: the date will only show the month, day, and year.
1212:
1213: =back
1214:
1215: Date elements contain only an option <nextstate> tag to determine
1216: the next state.
1217:
1218: Example:
1219:
1220: <date variable="DUE_DATE" hoursminutes="1">
1221: <nextstate>choose_why</nextstate>
1222: </date>
1223:
1224: =cut
1225:
1226: no strict;
1227: @ISA = ("Apache::lonhelper::element");
1228: use strict;
1229:
1230: use Time::localtime;
1231:
1232: BEGIN {
1233: &Apache::lonhelper::register('Apache::lonhelper::date',
1234: ('date'));
1235: }
1236:
1237: # Don't need to override the "new" from element
1238: sub new {
1239: my $ref = Apache::lonhelper::element->new();
1240: bless($ref);
1241: }
1242:
1243: my @months = ("January", "February", "March", "April", "May", "June", "July",
1244: "August", "September", "October", "November", "December");
1245:
1246: # CONSTRUCTION: Construct the message element from the XML
1247: sub start_date {
1248: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1249:
1250: if ($target ne 'helper') {
1251: return '';
1252: }
1253:
1254: $paramHash->{'variable'} = $token->[2]{'variable'};
1255: $helper->declareVar($paramHash->{'variable'});
1256: $paramHash->{'hoursminutes'} = $token->[2]{'hoursminutes'};
1257: }
1258:
1259: sub end_date {
1260: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1261:
1262: if ($target ne 'helper') {
1263: return '';
1264: }
1265: Apache::lonhelper::date->new();
1266: return '';
1267: }
1268:
1269: sub render {
1270: my $self = shift;
1271: my $result = "";
1272: my $var = $self->{'variable'};
1273:
1274: my $date;
1275:
1276: # Default date: The current hour.
1277: $date = localtime();
1278: $date->min(0);
1279:
1280: if (defined $self->{ERROR_MSG}) {
1281: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1282: }
1283:
1284: # Month
1285: my $i;
1286: $result .= "<select name='${var}month'>\n";
1287: for ($i = 0; $i < 12; $i++) {
1288: if ($i == $date->mon) {
1289: $result .= "<option value='$i' selected>";
1290: } else {
1291: $result .= "<option value='$i'>";
1292: }
1293: $result .= $months[$i] . "</option>\n";
1294: }
1295: $result .= "</select>\n";
1296:
1297: # Day
1298: $result .= "<select name='${var}day'>\n";
1299: for ($i = 1; $i < 32; $i++) {
1300: if ($i == $date->mday) {
1301: $result .= '<option selected>';
1302: } else {
1303: $result .= '<option>';
1304: }
1305: $result .= "$i</option>\n";
1306: }
1307: $result .= "</select>,\n";
1308:
1309: # Year
1310: $result .= "<select name='${var}year'>\n";
1311: for ($i = 2000; $i < 2030; $i++) { # update this after 64-bit dates
1312: if ($date->year + 1900 == $i) {
1313: $result .= "<option selected>";
1314: } else {
1315: $result .= "<option>";
1316: }
1317: $result .= "$i</option>\n";
1318: }
1319: $result .= "</select>,\n";
1320:
1321: # Display Hours and Minutes if they are called for
1322: if ($self->{'hoursminutes'}) {
1323: # Build hour
1324: $result .= "<select name='${var}hour'>\n";
1325: $result .= "<option " . ($date->hour == 0 ? 'selected ':'') .
1326: " value='0'>midnight</option>\n";
1327: for ($i = 1; $i < 12; $i++) {
1328: if ($date->hour == $i) {
1329: $result .= "<option selected value='$i'>$i a.m.</option>\n";
1330: } else {
1331: $result .= "<option value='$i'>$i a.m</option>\n";
1332: }
1333: }
1334: $result .= "<option " . ($date->hour == 12 ? 'selected ':'') .
1335: " value='12'>noon</option>\n";
1336: for ($i = 13; $i < 24; $i++) {
1337: my $printedHour = $i - 12;
1338: if ($date->hour == $i) {
1339: $result .= "<option selected value='$i'>$printedHour p.m.</option>\n";
1340: } else {
1341: $result .= "<option value='$i'>$printedHour p.m.</option>\n";
1342: }
1343: }
1344:
1345: $result .= "</select> :\n";
1346:
1347: $result .= "<select name='${var}minute'>\n";
1348: for ($i = 0; $i < 60; $i++) {
1349: my $printedMinute = $i;
1350: if ($i < 10) {
1351: $printedMinute = "0" . $printedMinute;
1352: }
1353: if ($date->min == $i) {
1354: $result .= "<option selected>";
1355: } else {
1356: $result .= "<option>";
1357: }
1358: $result .= "$printedMinute</option>\n";
1359: }
1360: $result .= "</select>\n";
1361: }
1362:
1363: return $result;
1364:
1365: }
1366: # If a NEXTSTATE was given, switch to it
1367: sub postprocess {
1368: my $self = shift;
1369: my $var = $self->{'variable'};
1370: my $month = $ENV{'form.' . $var . 'month'};
1371: my $day = $ENV{'form.' . $var . 'day'};
1372: my $year = $ENV{'form.' . $var . 'year'};
1373: my $min = 0;
1374: my $hour = 0;
1375: if ($self->{'hoursminutes'}) {
1376: $min = $ENV{'form.' . $var . 'minute'};
1377: $hour = $ENV{'form.' . $var . 'hour'};
1378: }
1379:
1380: my $chosenDate = Time::Local::timelocal(0, $min, $hour, $day, $month, $year);
1381: # Check to make sure that the date was not automatically co-erced into a
1382: # valid date, as we want to flag that as an error
1383: # This happens for "Feb. 31", for instance, which is coerced to March 2 or
1384: # 3, depending on if it's a leapyear
1385: my $checkDate = localtime($chosenDate);
1386:
1387: if ($checkDate->mon != $month || $checkDate->mday != $day ||
1388: $checkDate->year + 1900 != $year) {
1389: $self->{ERROR_MSG} = "Can't use " . $months[$month] . " $day, $year as a "
1390: . "date because it doesn't exist. Please enter a valid date.";
1391: return 0;
1392: }
1393:
1394: $helper->{VARS}->{$var} = $chosenDate;
1395:
1396: if (defined($self->{NEXTSTATE})) {
1397: $helper->changeState($self->{NEXTSTATE});
1398: }
1399:
1400: return 1;
1401: }
1402: 1;
1403:
1404: package Apache::lonhelper::resource;
1405:
1406: =pod
1407:
1408: =head2 Element: resource
1409:
1410: <resource> elements allow the user to select one or multiple resources
1411: from the current course. You can filter out which resources they can view,
1412: and filter out which resources they can select. The course will always
1413: be displayed fully expanded, because of the difficulty of maintaining
1414: selections across folder openings and closings. If this is fixed, then
1415: the user can manipulate the folders.
1416:
1417: <resource> takes the standard variable attribute to control what helper
1418: variable stores the results. It also takes a "multichoice" attribute,
1419: which controls whether the user can select more then one resource. The
1420: "toponly" attribute controls whether the resource display shows just the
1421: resources in that sequence, or recurses into all sub-sequences, defaulting
1422: to false. The "suppressEmptySequences" attribute reflects the
1423: suppressEmptySequences argument to the render routine, which will cause
1424: folders that have all of their contained resources filtered out to also
1425: be filtered out.
1426:
1427: B<SUB-TAGS>
1428:
1429: =over 4
1430:
1431: =item * <filterfunc>: If you want to filter what resources are displayed
1432: to the user, use a filter func. The <filterfunc> tag should contain
1433: Perl code that when wrapped with "sub { my $res = shift; " and "}" is
1434: a function that returns true if the resource should be displayed,
1435: and false if it should be skipped. $res is a resource object.
1436: (See Apache::lonnavmaps documentation for information about the
1437: resource object.)
1438:
1439: =item * <choicefunc>: Same as <filterfunc>, except that controls whether
1440: the given resource can be chosen. (It is almost always a good idea to
1441: show the user the folders, for instance, but you do not always want to
1442: let the user select them.)
1443:
1444: =item * <nextstate>: Standard nextstate behavior.
1445:
1446: =item * <valuefunc>: This function controls what is returned by the resource
1447: when the user selects it. Like filterfunc and choicefunc, it should be
1448: a function fragment that when wrapped by "sub { my $res = shift; " and
1449: "}" returns a string representing what you want to have as the value. By
1450: default, the value will be the resource ID of the object ($res->{ID}).
1451:
1452: =item * <mapurl>: If the URL of a map is given here, only that map
1453: will be displayed, instead of the whole course.
1454:
1455: =back
1456:
1457: =cut
1458:
1459: no strict;
1460: @ISA = ("Apache::lonhelper::element");
1461: use strict;
1462:
1463: BEGIN {
1464: &Apache::lonhelper::register('Apache::lonhelper::resource',
1465: ('resource', 'filterfunc',
1466: 'choicefunc', 'valuefunc',
1467: 'mapurl'));
1468: }
1469:
1470: sub new {
1471: my $ref = Apache::lonhelper::element->new();
1472: bless($ref);
1473: }
1474:
1475: # CONSTRUCTION: Construct the message element from the XML
1476: sub start_resource {
1477: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1478:
1479: if ($target ne 'helper') {
1480: return '';
1481: }
1482:
1483: $paramHash->{'variable'} = $token->[2]{'variable'};
1484: $helper->declareVar($paramHash->{'variable'});
1485: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1486: $paramHash->{'suppressEmptySequences'} = $token->[2]{'suppressEmptySequences'};
1487: $paramHash->{'toponly'} = $token->[2]{'toponly'};
1488: return '';
1489: }
1490:
1491: sub end_resource {
1492: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1493:
1494: if ($target ne 'helper') {
1495: return '';
1496: }
1497: if (!defined($paramHash->{FILTER_FUNC})) {
1498: $paramHash->{FILTER_FUNC} = sub {return 1;};
1499: }
1500: if (!defined($paramHash->{CHOICE_FUNC})) {
1501: $paramHash->{CHOICE_FUNC} = sub {return 1;};
1502: }
1503: if (!defined($paramHash->{VALUE_FUNC})) {
1504: $paramHash->{VALUE_FUNC} = sub {my $res = shift; return $res->{ID}; };
1505: }
1506: Apache::lonhelper::resource->new();
1507: return '';
1508: }
1509:
1510: sub start_filterfunc {
1511: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1512:
1513: if ($target ne 'helper') {
1514: return '';
1515: }
1516:
1517: my $contents = Apache::lonxml::get_all_text('/filterfunc',
1518: $parser);
1519: $contents = 'sub { my $res = shift; ' . $contents . '}';
1520: $paramHash->{FILTER_FUNC} = eval $contents;
1521: }
1522:
1523: sub end_filterfunc { return ''; }
1524:
1525: sub start_choicefunc {
1526: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1527:
1528: if ($target ne 'helper') {
1529: return '';
1530: }
1531:
1532: my $contents = Apache::lonxml::get_all_text('/choicefunc',
1533: $parser);
1534: $contents = 'sub { my $res = shift; ' . $contents . '}';
1535: $paramHash->{CHOICE_FUNC} = eval $contents;
1536: }
1537:
1538: sub end_choicefunc { return ''; }
1539:
1540: sub start_valuefunc {
1541: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1542:
1543: if ($target ne 'helper') {
1544: return '';
1545: }
1546:
1547: my $contents = Apache::lonxml::get_all_text('/valuefunc',
1548: $parser);
1549: $contents = 'sub { my $res = shift; ' . $contents . '}';
1550: $paramHash->{VALUE_FUNC} = eval $contents;
1551: }
1552:
1553: sub end_valuefunc { return ''; }
1554:
1555: sub start_mapurl {
1556: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1557:
1558: if ($target ne 'helper') {
1559: return '';
1560: }
1561:
1562: my $contents = Apache::lonxml::get_all_text('/mapurl',
1563: $parser);
1564: $paramHash->{MAP_URL} = $contents;
1565: }
1566:
1567: sub end_mapurl { return ''; }
1568:
1569: # A note, in case I don't get to this before I leave.
1570: # If someone complains about the "Back" button returning them
1571: # to the previous folder state, instead of returning them to
1572: # the previous helper state, the *correct* answer is for the helper
1573: # to keep track of how many times the user has manipulated the folders,
1574: # and feed that to the history.go() call in the helper rendering routines.
1575: # If done correctly, the helper itself can keep track of how many times
1576: # it renders the same states, so it doesn't go in just this state, and
1577: # you can lean on the browser back button to make sure it all chains
1578: # correctly.
1579: # Right now, though, I'm just forcing all folders open.
1580:
1581: sub render {
1582: my $self = shift;
1583: my $result = "";
1584: my $var = $self->{'variable'};
1585: my $curVal = $helper->{VARS}->{$var};
1586:
1587: my $buttons = '';
1588:
1589: if ($self->{'multichoice'}) {
1590: $result = <<SCRIPT;
1591: <script>
1592: function checkall(value, checkName) {
1593: for (i=0; i<document.forms.helpform.elements.length; i++) {
1594: ele = document.forms.helpform.elements[i];
1595: if (ele.name == checkName + '.forminput') {
1596: document.forms.helpform.elements[i].checked=value;
1597: }
1598: }
1599: }
1600: </script>
1601: SCRIPT
1602: $buttons = <<BUTTONS;
1603: <br />
1604: <input type="button" onclick="checkall(true, '$var')" value="Select All Resources" />
1605: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Resources" />
1606: <br />
1607: BUTTONS
1608: }
1609:
1610: if (defined $self->{ERROR_MSG}) {
1611: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1612: }
1613:
1614: $result .= $buttons;
1615:
1616: my $filterFunc = $self->{FILTER_FUNC};
1617: my $choiceFunc = $self->{CHOICE_FUNC};
1618: my $valueFunc = $self->{VALUE_FUNC};
1619: my $mapUrl = $self->{MAP_URL};
1620: my $multichoice = $self->{'multichoice'};
1621:
1622: # Create the composite function that renders the column on the nav map
1623: # have to admit any language that lets me do this can't be all bad
1624: # - Jeremy (Pythonista) ;-)
1625: my $checked = 0;
1626: my $renderColFunc = sub {
1627: my ($resource, $part, $params) = @_;
1628:
1629: my $inputType;
1630: if ($multichoice) { $inputType = 'checkbox'; }
1631: else {$inputType = 'radio'; }
1632:
1633: if (!&$choiceFunc($resource)) {
1634: return '<td> </td>';
1635: } else {
1636: my $col = "<td><input type='$inputType' name='${var}.forminput' ";
1637: if (!$checked && !$multichoice) {
1638: $col .= "checked ";
1639: $checked = 1;
1640: }
1641: $col .= "value='" .
1642: HTML::Entities::encode(&$valueFunc($resource))
1643: . "' /></td>";
1644: return $col;
1645: }
1646: };
1647:
1648: $ENV{'form.condition'} = !$self->{'toponly'};
1649: $result .=
1650: &Apache::lonnavmaps::render( { 'cols' => [$renderColFunc,
1651: Apache::lonnavmaps::resource()],
1652: 'showParts' => 0,
1653: 'filterFunc' => $filterFunc,
1654: 'resource_no_folder_link' => 1,
1655: 'suppressEmptySequences' => $self->{'suppressEmptySequences'},
1656: 'iterator_map' => $mapUrl }
1657: );
1658:
1659: $result .= $buttons;
1660:
1661: return $result;
1662: }
1663:
1664: sub postprocess {
1665: my $self = shift;
1666:
1667: if ($self->{'multichoice'} && !$helper->{VARS}->{$self->{'variable'}}) {
1668: $self->{ERROR_MSG} = 'You must choose at least one resource to continue.';
1669: return 0;
1670: }
1671:
1672: if (defined($self->{NEXTSTATE})) {
1673: $helper->changeState($self->{NEXTSTATE});
1674: }
1675:
1676: return 1;
1677: }
1678:
1679: 1;
1680:
1681: package Apache::lonhelper::student;
1682:
1683: =pod
1684:
1685: =head2 Element: student
1686:
1687: Student elements display a choice of students enrolled in the current
1688: course. Currently it is primitive; this is expected to evolve later.
1689:
1690: Student elements take two attributes: "variable", which means what
1691: it usually does, and "multichoice", which if true allows the user
1692: to select multiple students.
1693:
1694: =cut
1695:
1696: no strict;
1697: @ISA = ("Apache::lonhelper::element");
1698: use strict;
1699:
1700:
1701:
1702: BEGIN {
1703: &Apache::lonhelper::register('Apache::lonhelper::student',
1704: ('student'));
1705: }
1706:
1707: sub new {
1708: my $ref = Apache::lonhelper::element->new();
1709: bless($ref);
1710: }
1711:
1712: sub start_student {
1713: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1714:
1715: if ($target ne 'helper') {
1716: return '';
1717: }
1718:
1719: $paramHash->{'variable'} = $token->[2]{'variable'};
1720: $helper->declareVar($paramHash->{'variable'});
1721: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1722: if (defined($token->[2]{'nextstate'})) {
1723: $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
1724: }
1725:
1726: }
1727:
1728: sub end_student {
1729: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1730:
1731: if ($target ne 'helper') {
1732: return '';
1733: }
1734: Apache::lonhelper::student->new();
1735: }
1736:
1737: sub render {
1738: my $self = shift;
1739: my $result = '';
1740: my $buttons = '';
1741: my $var = $self->{'variable'};
1742:
1743: if ($self->{'multichoice'}) {
1744: $result = <<SCRIPT;
1745: <script>
1746: function checkall(value, checkName) {
1747: for (i=0; i<document.forms.helpform.elements.length; i++) {
1748: ele = document.forms.helpform.elements[i];
1749: if (ele.name == checkName + '.forminput') {
1750: document.forms.helpform.elements[i].checked=value;
1751: }
1752: }
1753: }
1754: </script>
1755: SCRIPT
1756: $buttons = <<BUTTONS;
1757: <br />
1758: <input type="button" onclick="checkall(true, '$var')" value="Select All Students" />
1759: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Students" />
1760: <br />
1761: BUTTONS
1762: }
1763:
1764: if (defined $self->{ERROR_MSG}) {
1765: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1766: }
1767:
1768: # Load up the students
1769: my $choices = &Apache::loncoursedata::get_classlist();
1770: my @keys = keys %{$choices};
1771:
1772: # Constants
1773: my $section = Apache::loncoursedata::CL_SECTION();
1774: my $fullname = Apache::loncoursedata::CL_FULLNAME();
1775:
1776: # Sort by: Section, name
1777: @keys = sort {
1778: if ($choices->{$a}->[$section] ne $choices->{$b}->[$section]) {
1779: return $choices->{$a}->[$section] cmp $choices->{$b}->[$section];
1780: }
1781: return $choices->{$a}->[$fullname] cmp $choices->{$b}->[$fullname];
1782: } @keys;
1783:
1784: my $type = 'radio';
1785: if ($self->{'multichoice'}) { $type = 'checkbox'; }
1786: $result .= "<table cellspacing='2' cellpadding='2' border='0'>\n";
1787: $result .= "<tr><td></td><td align='center'><b>Student Name</b></td>".
1788: "<td align='center'><b>Section</b></td></tr>";
1789:
1790: my $checked = 0;
1791: foreach (@keys) {
1792: $result .= "<tr><td><input type='$type' name='" .
1793: $self->{'variable'} . '.forminput' . "'";
1794:
1795: if (!$self->{'multichoice'} && !$checked) {
1796: $result .= " checked ";
1797: $checked = 1;
1798: }
1799: $result .=
1800: " value='" . HTML::Entities::encode($_ . ':' . $choices->{$_}->[$section])
1801: . "' /></td><td>"
1802: . HTML::Entities::encode($choices->{$_}->[$fullname])
1803: . "</td><td align='center'>"
1804: . HTML::Entities::encode($choices->{$_}->[$section])
1805: . "</td></tr>\n";
1806: }
1807:
1808: $result .= "</table>\n\n";
1809: $result .= $buttons;
1810:
1811: return $result;
1812: }
1813:
1814: sub postprocess {
1815: my $self = shift;
1816:
1817: my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
1818: if (!$result) {
1819: $self->{ERROR_MSG} = 'You must choose at least one student '.
1820: 'to continue.';
1821: return 0;
1822: }
1823:
1824: if (defined($self->{NEXTSTATE})) {
1825: $helper->changeState($self->{NEXTSTATE});
1826: }
1827:
1828: return 1;
1829: }
1830:
1831: 1;
1832:
1833: package Apache::lonhelper::files;
1834:
1835: =pod
1836:
1837: =head2 Element: files
1838:
1839: files allows the users to choose files from a given directory on the
1840: server. It is always multichoice and stores the result as a triple-pipe
1841: delimited entry in the helper variables.
1842:
1843: Since it is extremely unlikely that you can actually code a constant
1844: representing the directory you wish to allow the user to search, <files>
1845: takes a subroutine that returns the name of the directory you wish to
1846: have the user browse.
1847:
1848: files accepts the attribute "variable" to control where the files chosen
1849: are put. It accepts the attribute "multichoice" as the other attribute,
1850: defaulting to false, which if true will allow the user to select more
1851: then one choice.
1852:
1853: <files> accepts three subtags. One is the "nextstate" sub-tag that works
1854: as it does with the other tags. Another is a <filechoice> sub tag that
1855: is Perl code that, when surrounded by "sub {" and "}" will return a
1856: string representing what directory on the server to allow the user to
1857: choose files from. Finally, the <filefilter> subtag should contain Perl
1858: code that when surrounded by "sub { my $filename = shift; " and "}",
1859: returns a true value if the user can pick that file, or false otherwise.
1860: The filename passed to the function will be just the name of the file,
1861: with no path info.
1862:
1863: =cut
1864:
1865: no strict;
1866: @ISA = ("Apache::lonhelper::element");
1867: use strict;
1868:
1869: BEGIN {
1870: &Apache::lonhelper::register('Apache::lonhelper::files',
1871: ('files', 'filechoice', 'filefilter'));
1872: }
1873:
1874: sub new {
1875: my $ref = Apache::lonhelper::element->new();
1876: bless($ref);
1877: }
1878:
1879: sub start_files {
1880: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1881:
1882: if ($target ne 'helper') {
1883: return '';
1884: }
1885: $paramHash->{'variable'} = $token->[2]{'variable'};
1886: $helper->declareVar($paramHash->{'variable'});
1887: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1888: }
1889:
1890: sub end_files {
1891: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1892:
1893: if ($target ne 'helper') {
1894: return '';
1895: }
1896: if (!defined($paramHash->{FILTER_FUNC})) {
1897: $paramHash->{FILTER_FUNC} = sub { return 1; };
1898: }
1899: Apache::lonhelper::files->new();
1900: }
1901:
1902: sub start_filechoice {
1903: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1904:
1905: if ($target ne 'helper') {
1906: return '';
1907: }
1908: $paramHash->{'filechoice'} = Apache::lonxml::get_all_text('/filechoice',
1909: $parser);
1910: }
1911:
1912: sub end_filechoice { return ''; }
1913:
1914: sub start_filefilter {
1915: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1916:
1917: if ($target ne 'helper') {
1918: return '';
1919: }
1920:
1921: my $contents = Apache::lonxml::get_all_text('/filefilter',
1922: $parser);
1923: $contents = 'sub { my $filename = shift; ' . $contents . '}';
1924: $paramHash->{FILTER_FUNC} = eval $contents;
1925: }
1926:
1927: sub end_filefilter { return ''; }
1928:
1929: sub render {
1930: my $self = shift;
1931: my $result = '';
1932: my $var = $self->{'variable'};
1933:
1934: my $subdirFunc = eval('sub {' . $self->{'filechoice'} . '}');
1935: die 'Error in resource filter code for variable ' .
1936: {'variable'} . ', Perl said:' . $@ if $@;
1937:
1938: my $subdir = &$subdirFunc();
1939:
1940: my $filterFunc = $self->{FILTER_FUNC};
1941: my $buttons = '';
1942: my $type = 'radio';
1943: if ($self->{'multichoice'}) {
1944: $type = 'checkbox';
1945: }
1946:
1947: if ($self->{'multichoice'}) {
1948: $result = <<SCRIPT;
1949: <script>
1950: function checkall(value, checkName) {
1951: for (i=0; i<document.forms.helpform.elements.length; i++) {
1952: ele = document.forms.helpform.elements[i];
1953: if (ele.name == checkName + '.forminput') {
1954: document.forms.helpform.elements[i].checked=value;
1955: }
1956: }
1957: }
1958:
1959: function checkallclass(value, className) {
1960: for (i=0; i<document.forms.helpform.elements.length; i++) {
1961: ele = document.forms.helpform.elements[i];
1962: if (ele.type == "$type" && ele.onclick) {
1963: document.forms.helpform.elements[i].checked=value;
1964: }
1965: }
1966: }
1967: </script>
1968: SCRIPT
1969: $buttons = <<BUTTONS;
1970: <br />
1971: <input type="button" onclick="checkall(true, '$var')" value="Select All Files" />
1972: <input type="button" onclick="checkall(false, '$var')" value="Unselect All Files" />
1973: BUTTONS
1974:
1975: if ($helper->{VARS}->{'construction'}) {
1976: $buttons .= <<BUTTONS;
1977: <input type="button" onclick="checkallclass(true, 'Published')" value="Select All Published" />
1978: <input type="button" onclick="checkallclass(false, 'Published')" value="Unselect All Published" />
1979: <br />
1980: BUTTONS
1981: }
1982: }
1983:
1984: # Get the list of files in this directory.
1985: my @fileList;
1986:
1987: # If the subdirectory is in local CSTR space
1988: if ($subdir =~ m|/home/([^/]+)/public_html|) {
1989: my $user = $1;
1990: my $domain = $Apache::lonnet::perlvar{'lonDefDomain'};
1991: @fileList = &Apache::lonnet::dirlist($subdir, $domain, $user, '');
1992: } else {
1993: # local library server resource space
1994: @fileList = &Apache::lonnet::dirlist($subdir, $ENV{'user.domain'}, $ENV{'user.name'}, '');
1995: }
1996:
1997: $result .= $buttons;
1998:
1999: if (defined $self->{ERROR_MSG}) {
2000: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
2001: }
2002:
2003: $result .= '<table border="0" cellpadding="2" cellspacing="0">';
2004:
2005: # Keeps track if there are no choices, prints appropriate error
2006: # if there are none.
2007: my $choices = 0;
2008: # Print each legitimate file choice.
2009: for my $file (@fileList) {
2010: $file = (split(/&/, $file))[0];
2011: if ($file eq '.' || $file eq '..') {
2012: next;
2013: }
2014: my $fileName = $subdir .'/'. $file;
2015: if (&$filterFunc($file)) {
2016: my $status;
2017: my $color;
2018: if ($helper->{VARS}->{'construction'}) {
2019: ($status, $color) = @{fileState($subdir, $file)};
2020: } else {
2021: $status = '';
2022: $color = '';
2023: }
2024:
2025: # Netscape 4 is stupid and there's nowhere to put the
2026: # information on the input tag that the file is Published,
2027: # Unpublished, etc. In *real* browsers we can just say
2028: # "class='Published'" and check the className attribute of
2029: # the input tag, but Netscape 4 is too stupid to understand
2030: # that attribute, and un-comprehended attributes are not
2031: # reflected into the object model. So instead, what I do
2032: # is either have or don't have an "onclick" handler that
2033: # does nothing, give Published files the onclick handler, and
2034: # have the checker scripts check for that. Stupid and clumsy,
2035: # and only gives us binary "yes/no" information (at least I
2036: # couldn't figure out how to reach into the event handler's
2037: # actual code to retreive a value), but it works well enough
2038: # here.
2039:
2040: my $onclick = '';
2041: if ($status eq 'Published' && $helper->{VARS}->{'construction'}) {
2042: $onclick = 'onclick="a=1" ';
2043: }
2044: $result .= '<tr><td align="right"' . " bgcolor='$color'>" .
2045: "<input $onclick type='$type' name='" . $var
2046: . ".forminput' value='" . HTML::Entities::encode($fileName) .
2047: "'";
2048: if (!$self->{'multichoice'} && $choices == 0) {
2049: $result .= ' checked';
2050: }
2051: $result .= "/></td><td bgcolor='$color'>" . $file .
2052: "</td><td bgcolor='$color'>$status</td></tr>\n";
2053: $choices++;
2054: }
2055: }
2056:
2057: $result .= "</table>\n";
2058:
2059: if (!$choices) {
2060: $result .= '<font color="#FF0000">There are no files available to select in this directory. Please go back and select another option.</font><br /><br />';
2061: }
2062:
2063: $result .= $buttons;
2064:
2065: return $result;
2066: }
2067:
2068: # Determine the state of the file: Published, unpublished, modified.
2069: # Return the color it should be in and a label as a two-element array
2070: # reference.
2071: # Logic lifted from lonpubdir.pm, even though I don't know that it's still
2072: # the most right thing to do.
2073:
2074: sub fileState {
2075: my $constructionSpaceDir = shift;
2076: my $file = shift;
2077:
2078: my $docroot = $Apache::lonnet::perlvar{'lonDocRoot'};
2079: my $subdirpart = $constructionSpaceDir;
2080: $subdirpart =~ s/^\/home\/$ENV{'user.name'}\/public_html//;
2081: my $resdir = $docroot . '/res/' . $ENV{'user.domain'} . '/' . $ENV{'user.name'} .
2082: $subdirpart;
2083:
2084: my @constructionSpaceFileStat = stat($constructionSpaceDir . '/' . $file);
2085: my @resourceSpaceFileStat = stat($resdir . '/' . $file);
2086: if (!@resourceSpaceFileStat) {
2087: return ['Unpublished', '#FFCCCC'];
2088: }
2089:
2090: my $constructionSpaceFileModified = $constructionSpaceFileStat[9];
2091: my $resourceSpaceFileModified = $resourceSpaceFileStat[9];
2092:
2093: if ($constructionSpaceFileModified > $resourceSpaceFileModified) {
2094: return ['Modified', '#FFFFCC'];
2095: }
2096: return ['Published', '#CCFFCC'];
2097: }
2098:
2099: sub postprocess {
2100: my $self = shift;
2101: my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
2102: if (!$result) {
2103: $self->{ERROR_MSG} = 'You must choose at least one file '.
2104: 'to continue.';
2105: return 0;
2106: }
2107:
2108: if (defined($self->{NEXTSTATE})) {
2109: $helper->changeState($self->{NEXTSTATE});
2110: }
2111:
2112: return 1;
2113: }
2114:
2115: 1;
2116:
2117: package Apache::lonhelper::section;
2118:
2119: =pod
2120:
2121: =head2 Element: section
2122:
2123: <section> allows the user to choose one or more sections from the current
2124: course.
2125:
2126: It takes the standard attributes "variable", "multichoice", and
2127: "nextstate", meaning what they do for most other elements.
2128:
2129: =cut
2130:
2131: no strict;
2132: @ISA = ("Apache::lonhelper::choices");
2133: use strict;
2134:
2135: BEGIN {
2136: &Apache::lonhelper::register('Apache::lonhelper::section',
2137: ('section'));
2138: }
2139:
2140: sub new {
2141: my $ref = Apache::lonhelper::choices->new();
2142: bless($ref);
2143: }
2144:
2145: sub start_section {
2146: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2147:
2148: if ($target ne 'helper') {
2149: return '';
2150: }
2151:
2152: $paramHash->{CHOICES} = [];
2153:
2154: $paramHash->{'variable'} = $token->[2]{'variable'};
2155: $helper->declareVar($paramHash->{'variable'});
2156: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
2157: if (defined($token->[2]{'nextstate'})) {
2158: $paramHash->{NEXTSTATE} = $token->[2]{'nextstate'};
2159: }
2160:
2161: # Populate the CHOICES element
2162: my %choices;
2163:
2164: my $section = Apache::loncoursedata::CL_SECTION();
2165: my $classlist = Apache::loncoursedata::get_classlist();
2166: foreach (keys %$classlist) {
2167: my $sectionName = $classlist->{$_}->[$section];
2168: if (!$sectionName) {
2169: $choices{"No section assigned"} = "";
2170: } else {
2171: $choices{$sectionName} = $sectionName;
2172: }
2173: }
2174:
2175: for my $sectionName (sort(keys(%choices))) {
2176:
2177: push @{$paramHash->{CHOICES}}, [$sectionName, $sectionName];
2178: }
2179: }
2180:
2181: sub end_section {
2182: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2183:
2184: if ($target ne 'helper') {
2185: return '';
2186: }
2187: Apache::lonhelper::section->new();
2188: }
2189: 1;
2190:
2191: package Apache::lonhelper::general;
2192:
2193: =pod
2194:
2195: =head2 General-purpose tag: <exec>
2196:
2197: The contents of the exec tag are executed as Perl code, not inside a
2198: safe space, so the full range of $ENV and such is available. The code
2199: will be executed as a subroutine wrapped with the following code:
2200:
2201: "sub { my $helper = shift; my $state = shift;" and
2202:
2203: "}"
2204:
2205: The return value is ignored.
2206:
2207: $helper is the helper object. Feel free to add methods to the helper
2208: object to support whatever manipulation you may need to do (for instance,
2209: overriding the form location if the state is the final state; see
2210: lonparm.helper for an example).
2211:
2212: $state is the $paramHash that has currently been generated and may
2213: be manipulated by the code in exec. Note that the $state is not yet
2214: an actual state B<object>, it is just a hash, so do not expect to
2215: be able to call methods on it.
2216:
2217: =cut
2218:
2219: BEGIN {
2220: &Apache::lonhelper::register('Apache::lonhelper::general',
2221: 'exec', 'condition', 'clause',
2222: 'eval');
2223: }
2224:
2225: sub start_exec {
2226: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2227:
2228: if ($target ne 'helper') {
2229: return '';
2230: }
2231:
2232: my $code = &Apache::lonxml::get_all_text('/exec', $parser);
2233:
2234: $code = eval ('sub { my $helper = shift; my $state = shift; ' .
2235: $code . "}");
2236: die 'Error in <exec>, Perl said: '. $@ if $@;
2237: &$code($helper, $paramHash);
2238: }
2239:
2240: sub end_exec { return ''; }
2241:
2242: =pod
2243:
2244: =head2 General-purpose tag: <condition>
2245:
2246: The <condition> tag allows you to mask out parts of the helper code
2247: depending on some programatically determined condition. The condition
2248: tag contains a tag <clause> which contains perl code that when wrapped
2249: with "sub { my $helper = shift; my $state = shift; " and "}", returns
2250: a true value if the XML in the condition should be evaluated as a normal
2251: part of the helper, or false if it should be completely discarded.
2252:
2253: The <clause> tag must be the first sub-tag of the <condition> tag or
2254: it will not work as expected.
2255:
2256: =cut
2257:
2258: # The condition tag just functions as a marker, it doesn't have
2259: # to "do" anything. Technically it doesn't even have to be registered
2260: # with the lonxml code, but I leave this here to be explicit about it.
2261: sub start_condition { return ''; }
2262: sub end_condition { return ''; }
2263:
2264: sub start_clause {
2265: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2266:
2267: if ($target ne 'helper') {
2268: return '';
2269: }
2270:
2271: my $clause = Apache::lonxml::get_all_text('/clause', $parser);
2272: $clause = eval('sub { my $helper = shift; my $state = shift; '
2273: . $clause . '}');
2274: die 'Error in clause of condition, Perl said: ' . $@ if $@;
2275: if (!&$clause($helper, $paramHash)) {
2276: # Discard all text until the /condition.
2277: &Apache::lonxml::get_all_text('/condition', $parser);
2278: }
2279: }
2280:
2281: sub end_clause { return ''; }
2282:
2283: =pod
2284:
2285: =head2 General-purpose tag: <eval>
2286:
2287: The <eval> tag will be evaluated as a subroutine call passed in the
2288: current helper object and state hash as described in <condition> above,
2289: but is expected to return a string to be printed directly to the
2290: screen. This is useful for dynamically generating messages.
2291:
2292: =cut
2293:
2294: # This is basically a type of message.
2295: # Programmatically setting $paramHash->{NEXTSTATE} would work, though
2296: # it's probably bad form.
2297:
2298: sub start_eval {
2299: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2300:
2301: if ($target ne 'helper') {
2302: return '';
2303: }
2304:
2305: my $program = Apache::lonxml::get_all_text('/eval', $parser);
2306: $program = eval('sub { my $helper = shift; my $state = shift; '
2307: . $program . '}');
2308: die 'Error in eval code, Perl said: ' . $@ if $@;
2309: $paramHash->{MESSAGE_TEXT} = &$program($helper, $paramHash);
2310: }
2311:
2312: sub end_eval {
2313: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2314:
2315: if ($target ne 'helper') {
2316: return '';
2317: }
2318:
2319: Apache::lonhelper::message->new();
2320: }
2321:
2322: 1;
2323:
2324: package Apache::lonhelper::final;
2325:
2326: =pod
2327:
2328: =head2 Element: final
2329:
2330: <final> is a special element that works with helpers that use the <finalcode>
2331: tag. It goes through all the states and elements, executing the <finalcode>
2332: snippets and collecting the results. Finally, it takes the user out of the
2333: helper, going to a provided page.
2334:
2335: =cut
2336:
2337: no strict;
2338: @ISA = ("Apache::lonhelper::element");
2339: use strict;
2340:
2341: BEGIN {
2342: &Apache::lonhelper::register('Apache::lonhelper::final',
2343: ('final', 'exitpage'));
2344: }
2345:
2346: sub new {
2347: my $ref = Apache::lonhelper::element->new();
2348: bless($ref);
2349: }
2350:
2351: sub start_final { return ''; }
2352:
2353: sub end_final {
2354: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2355:
2356: if ($target ne 'helper') {
2357: return '';
2358: }
2359:
2360: Apache::lonhelper::final->new();
2361:
2362: return '';
2363: }
2364:
2365: sub start_exitpage {
2366: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2367:
2368: if ($target ne 'helper') {
2369: return '';
2370: }
2371:
2372: $paramHash->{EXIT_PAGE} = &Apache::lonxml::get_all_text('/exitpage',
2373: $parser);
2374:
2375: return '';
2376: }
2377:
2378: sub end_exitpage { return ''; }
2379:
2380: sub render {
2381: my $self = shift;
2382:
2383: my @results;
2384:
2385: # Collect all the results
2386: for my $stateName (keys %{$helper->{STATES}}) {
2387: my $state = $helper->{STATES}->{$stateName};
2388:
2389: for my $element (@{$state->{ELEMENTS}}) {
2390: if (defined($element->{FINAL_CODE})) {
2391: # Compile the code.
2392: my $code = 'sub { my $helper = shift; ' . $element->{FINAL_CODE} .
2393: '}';
2394: $code = eval($code);
2395: die 'Error while executing final code for element with var ' .
2396: $element->{'variable'} . ', Perl said: ' . $@ if $@;
2397:
2398: my $result = &$code($helper);
2399: if ($result) {
2400: push @results, $result;
2401: }
2402: }
2403: }
2404: }
2405:
2406: if (scalar(@results) == 0) {
2407: return '';
2408: }
2409:
2410: my $result = "<ul>\n";
2411: for my $re (@results) {
2412: $result .= ' <li>' . $re . "</li>\n";
2413: }
2414: return $result . '</ul>';
2415: }
2416:
2417: 1;
2418:
2419: package Apache::lonhelper::parmwizfinal;
2420:
2421: # This is the final state for the parmwizard. It is not generally useful,
2422: # so it is not perldoc'ed. It does its own processing.
2423: # It is represented with <parmwizfinal />, and
2424: # should later be moved to lonparmset.pm .
2425:
2426: no strict;
2427: @ISA = ('Apache::lonhelper::element');
2428: use strict;
2429:
2430: BEGIN {
2431: &Apache::lonhelper::register('Apache::lonhelper::parmwizfinal',
2432: ('parmwizfinal'));
2433: }
2434:
2435: use Time::localtime;
2436:
2437: sub new {
2438: my $ref = Apache::lonhelper::choices->new();
2439: bless ($ref);
2440: }
2441:
2442: sub start_parmwizfinal { return ''; }
2443:
2444: sub end_parmwizfinal {
2445: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
2446:
2447: if ($target ne 'helper') {
2448: return '';
2449: }
2450: Apache::lonhelper::parmwizfinal->new();
2451: }
2452:
2453: # Renders a form that, when submitted, will form the input to lonparmset.pm
2454: sub render {
2455: my $self = shift;
2456: my $vars = $helper->{VARS};
2457:
2458: # FIXME: Unify my designators with the standard ones
2459: my %dateTypeHash = ('open_date' => "Opening Date",
2460: 'due_date' => "Due Date",
2461: 'answer_date' => "Answer Date");
2462: my %parmTypeHash = ('open_date' => "0_opendate",
2463: 'due_date' => "0_duedate",
2464: 'answer_date' => "0_answerdate");
2465:
2466: my $affectedResourceId = "";
2467: my $parm_name = $parmTypeHash{$vars->{ACTION_TYPE}};
2468: my $level = "";
2469: my $resourceString;
2470: my $symb;
2471: my $paramlevel;
2472:
2473: # Print the granularity, depending on the action
2474: if ($vars->{GRANULARITY} eq 'whole_course') {
2475: $resourceString .= '<li>for <b>all resources in the course</b></li>';
2476: $level = 9; # general course, see lonparmset.pm perldoc
2477: $affectedResourceId = "0.0";
2478: $symb = 'a';
2479: $paramlevel = 'general';
2480: } elsif ($vars->{GRANULARITY} eq 'map') {
2481: my $navmap = Apache::lonnavmaps::navmap->new(
2482: $ENV{"request.course.fn"}.".db",
2483: $ENV{"request.course.fn"}."_parms.db", 0, 0);
2484: my $res = $navmap->getById($vars->{RESOURCE_ID});
2485: my $title = $res->compTitle();
2486: $symb = $res->symb();
2487: $navmap->untieHashes();
2488: $resourceString .= "<li>for the map named <b>$title</b></li>";
2489: $level = 8;
2490: $affectedResourceId = $vars->{RESOURCE_ID};
2491: $paramlevel = 'map';
2492: } else {
2493: my $navmap = Apache::lonnavmaps::navmap->new(
2494: $ENV{"request.course.fn"}.".db",
2495: $ENV{"request.course.fn"}."_parms.db", 0, 0);
2496: my $res = $navmap->getById($vars->{RESOURCE_ID});
2497: $symb = $res->symb();
2498: my $title = $res->compTitle();
2499: $navmap->untieHashes();
2500: $resourceString .= "<li>for the resource named <b>$title</b></li>";
2501: $level = 7;
2502: $affectedResourceId = $vars->{RESOURCE_ID};
2503: $paramlevel = 'full';
2504: }
2505:
2506: my $result = "<form name='helpform' method='get' action='/adm/parmset#$affectedResourceId&$parm_name&$level'>\n";
2507: $result .= '<p>Confirm that this information is correct, then click "Finish Wizard" to complete setting the parameter.<ul>';
2508:
2509: # Print the type of manipulation:
2510: $result .= '<li>Setting the <b>' . $dateTypeHash{$vars->{ACTION_TYPE}}
2511: . "</b></li>\n";
2512: if ($vars->{ACTION_TYPE} eq 'due_date' ||
2513: $vars->{ACTION_TYPE} eq 'answer_date') {
2514: # for due dates, we default to "date end" type entries
2515: $result .= "<input type='hidden' name='recent_date_end' " .
2516: "value='" . $vars->{PARM_DATE} . "' />\n";
2517: $result .= "<input type='hidden' name='pres_value' " .
2518: "value='" . $vars->{PARM_DATE} . "' />\n";
2519: $result .= "<input type='hidden' name='pres_type' " .
2520: "value='date_end' />\n";
2521: } elsif ($vars->{ACTION_TYPE} eq 'open_date') {
2522: $result .= "<input type='hidden' name='recent_date_start' ".
2523: "value='" . $vars->{PARM_DATE} . "' />\n";
2524: $result .= "<input type='hidden' name='pres_value' " .
2525: "value='" . $vars->{PARM_DATE} . "' />\n";
2526: $result .= "<input type='hidden' name='pres_type' " .
2527: "value='date_start' />\n";
2528: }
2529:
2530: $result .= $resourceString;
2531:
2532: # Print targets
2533: if ($vars->{TARGETS} eq 'course') {
2534: $result .= '<li>for <b>all students in course</b></li>';
2535: } elsif ($vars->{TARGETS} eq 'section') {
2536: my $section = $vars->{SECTION_NAME};
2537: $result .= "<li>for section <b>$section</b></li>";
2538: $level -= 3;
2539: $result .= "<input type='hidden' name='csec' value='" .
2540: HTML::Entities::encode($section) . "' />\n";
2541: } else {
2542: # FIXME: This is probably wasteful! Store the name!
2543: my $classlist = Apache::loncoursedata::get_classlist();
2544: my $username = $vars->{USER_NAME};
2545: # Chop off everything after the last colon (section)
2546: $username = substr($username, 0, rindex($username, ':'));
2547: my $name = $classlist->{$username}->[6];
2548: $result .= "<li>for <b>$name</b></li>";
2549: $level -= 6;
2550: my ($uname, $udom) = split /:/, $vars->{USER_NAME};
2551: $result .= "<input type='hidden' name='uname' value='".
2552: HTML::Entities::encode($uname) . "' />\n";
2553: $result .= "<input type='hidden' name='udom' value='".
2554: HTML::Entities::encode($udom) . "' />\n";
2555: }
2556:
2557: # Print value
2558: $result .= "<li>to <b>" . ctime($vars->{PARM_DATE}) . "</b> (" .
2559: Apache::lonnavmaps::timeToHumanString($vars->{PARM_DATE})
2560: . ")</li>\n";
2561:
2562: # print pres_marker
2563: $result .= "\n<input type='hidden' name='pres_marker'" .
2564: " value='$affectedResourceId&$parm_name&$level' />\n";
2565:
2566: # Make the table appear
2567: $result .= "\n<input type='hidden' value='true' name='prevvisit' />";
2568: $result .= "\n<input type='hidden' value='all' name='pschp' />";
2569: $result .= "\n<input type='hidden' value='$symb' name='pssymb' />";
2570: $result .= "\n<input type='hidden' value='$paramlevel' name='parmlev' />";
2571:
2572: $result .= "<br /><br /><center><input type='submit' value='Finish Helper' /></center></form>\n";
2573:
2574: return $result;
2575: }
2576:
2577: sub overrideForm {
2578: return 1;
2579: }
2580:
2581: 1;
2582:
2583: __END__
2584:
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