Annotation of loncom/interface/lonhelper.pm, revision 1.9
1.1 bowersj2 1: # The LearningOnline Network with CAPA
2: # .helper XML handler to implement the LON-CAPA helper
3: #
1.6 bowersj2 4: # $Id: lonhelper.pm,v 1.5 2003/04/10 18:02:09 bowersj2 Exp $
1.1 bowersj2 5: #
6: # Copyright Michigan State University Board of Trustees
7: #
8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
9: #
10: # LON-CAPA is free software; you can redistribute it and/or modify
11: # it under the terms of the GNU General Public License as published by
12: # the Free Software Foundation; either version 2 of the License, or
13: # (at your option) any later version.
14: #
15: # LON-CAPA is distributed in the hope that it will be useful,
16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18: # GNU General Public License for more details.
19: #
20: # You should have received a copy of the GNU General Public License
21: # along with LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
28: # (Page Handler
29: #
30: # (.helper handler
31: #
32:
1.3 bowersj2 33: =pod
34:
35: =head1 lonhelper - HTML Helper framework for LON-CAPA
36:
37: Helpers, often known as "wizards", are well-established UI widgets that users
38: feel comfortable with. It can take a complicated multidimensional problem the
39: user has and turn it into a series of bite-sized one-dimensional questions.
40:
41: For developers, helpers provide an easy way to bundle little bits of functionality
42: for the user, without having to write the tedious state-maintenence code.
43:
44: Helpers are defined as XML documents, placed in the /home/httpd/html/adm/helpers
45: directory and having the .helper file extension. For examples, see that directory.
46:
47: All classes are in the Apache::lonhelper namespace.
48:
49: =head2 lonhelper XML file format
50:
51: A helper consists of a top-level <helper> tag which contains a series of states.
52: Each state contains one or more state elements, which are what the user sees, like
53: messages, resource selections, or date queries.
54:
55: The helper tag is required to have one attribute, "title", which is the name
56: of the helper itself, such as "Parameter helper".
57:
58: =head2 State tags
59:
60: State tags are required to have an attribute "name", which is the symbolic
1.7 bowersj2 61: name of the state and will not be directly seen by the user. The helper is
62: required to have one state named "START", which is the state the helper
1.5 bowersj2 63: will start with. By convention, this state should clearly describe what
1.3 bowersj2 64: the helper will do for the user, and may also include the first information
65: entry the user needs to do for the helper.
66:
67: State tags are also required to have an attribute "title", which is the
68: human name of the state, and will be displayed as the header on top of
69: the screen for the user.
70:
71: =head2 Example Helper Skeleton
72:
73: An example of the tags so far:
74:
75: <helper title="Example Helper">
76: <state name="START" title="Demonstrating the Example Helper">
77: <!-- notice this is the START state the wizard requires -->
78: </state>
79: <state name="GET_NAME" title="Enter Student Name">
80: </state>
81: </helper>
82:
83: Of course this does nothing. In order for the wizard to do something, it is
84: necessary to put actual elements into the wizard. Documentation for each
85: of these elements follows.
86:
87: =cut
88:
1.1 bowersj2 89: package Apache::lonhelper;
1.2 bowersj2 90: use Apache::Constants qw(:common);
91: use Apache::File;
1.3 bowersj2 92: use Apache::lonxml;
1.2 bowersj2 93:
1.7 bowersj2 94: # Register all the tags with the helper, so the helper can
95: # push and pop them
96:
97: my @helperTags;
98:
99: sub register {
100: my ($namespace, @tags) = @_;
101:
102: for my $tag (@tags) {
103: push @helperTags, [$namespace, $tag];
104: }
105: }
106:
1.2 bowersj2 107: BEGIN {
1.7 bowersj2 108: Apache::lonxml::register('Apache::lonhelper',
109: ('helper'));
110: register('Apache::lonhelper', ('state'));
1.2 bowersj2 111: }
112:
1.7 bowersj2 113: # Since all helpers are only three levels deep (helper tag, state tag,
1.3 bowersj2 114: # substate type), it's easier and more readble to explicitly track
115: # those three things directly, rather then futz with the tag stack
116: # every time.
117: my $helper;
118: my $state;
119: my $substate;
1.4 bowersj2 120: # To collect parameters, the contents of the subtags are collected
121: # into this paramHash, then passed to the element object when the
122: # end of the element tag is located.
123: my $paramHash;
1.2 bowersj2 124:
125: sub handler {
1.3 bowersj2 126: my $r = shift;
1.2 bowersj2 127: $ENV{'request.uri'} = $r->uri();
128: my $filename = '/home/httpd/html' . $r->uri();
129: my $fh = Apache::File->new($filename);
130: my $file;
1.3 bowersj2 131: read $fh, $file, 100000000;
132:
133: Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});
134:
135: # Send header, don't cache this page
136: if ($r->header_only) {
137: if ($ENV{'browser.mathml'}) {
138: $r->content_type('text/xml');
139: } else {
140: $r->content_type('text/html');
141: }
142: $r->send_http_header;
143: return OK;
144: }
145: if ($ENV{'browser.mathml'}) {
146: $r->content_type('text/xml');
147: } else {
148: $r->content_type('text/html');
149: }
150: $r->send_http_header;
151: $r->rflush();
1.2 bowersj2 152:
1.3 bowersj2 153: # Discard result, we just want the objects that get created by the
154: # xml parsing
155: &Apache::lonxml::xmlparse($r, 'helper', $file);
1.2 bowersj2 156:
1.3 bowersj2 157: $r->print($helper->display());
1.7 bowersj2 158: return OK;
1.2 bowersj2 159: }
160:
161: sub start_helper {
162: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
163:
164: if ($target ne 'helper') {
165: return '';
166: }
1.7 bowersj2 167:
168: for my $tagList (@helperTags) {
169: Apache::lonxml::register($tagList->[0], $tagList->[1]);
170: }
1.2 bowersj2 171:
1.3 bowersj2 172: $helper = Apache::lonhelper::helper->new($token->[2]{'title'});
1.4 bowersj2 173: return '';
1.2 bowersj2 174: }
175:
176: sub end_helper {
177: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
178:
1.3 bowersj2 179: if ($target ne 'helper') {
180: return '';
181: }
1.7 bowersj2 182:
183: for my $tagList (@helperTags) {
184: Apache::lonxml::deregister($tagList->[0], $tagList->[1]);
185: }
186:
1.4 bowersj2 187: return '';
1.2 bowersj2 188: }
1.1 bowersj2 189:
1.3 bowersj2 190: sub start_state {
191: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
192:
193: if ($target ne 'helper') {
194: return '';
195: }
196:
197: $state = Apache::lonhelper::state->new($token->[2]{'name'},
198: $token->[2]{'title'});
199: return '';
200: }
201:
202: # don't need this, so ignore it
203: sub end_state {
204: return '';
205: }
206:
1.1 bowersj2 207: 1;
208:
1.3 bowersj2 209: package Apache::lonhelper::helper;
210:
211: use Digest::MD5 qw(md5_hex);
212: use HTML::Entities;
213: use Apache::loncommon;
214: use Apache::File;
215:
216: sub new {
217: my $proto = shift;
218: my $class = ref($proto) || $proto;
219: my $self = {};
220:
221: $self->{TITLE} = shift;
222:
223: # If there is a state from the previous form, use that. If there is no
224: # state, use the start state parameter.
225: if (defined $ENV{"form.CURRENT_STATE"})
226: {
227: $self->{STATE} = $ENV{"form.CURRENT_STATE"};
228: }
229: else
230: {
231: $self->{STATE} = "START";
232: }
233:
234: $self->{TOKEN} = $ENV{'form.TOKEN'};
235: # If a token was passed, we load that in. Otherwise, we need to create a
236: # new storage file
237: # Tried to use standard Tie'd hashes, but you can't seem to take a
238: # reference to a tied hash and write to it. I'd call that a wart.
239: if ($self->{TOKEN}) {
240: # Validate the token before trusting it
241: if ($self->{TOKEN} !~ /^[a-f0-9]{32}$/) {
242: # Not legit. Return nothing and let all hell break loose.
243: # User shouldn't be doing that!
244: return undef;
245: }
246:
247: # Get the hash.
248: $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN}); # Note the token is not the literal file
249:
250: my $file = Apache::File->new($self->{FILENAME});
251: my $contents = <$file>;
1.5 bowersj2 252:
253: # Now load in the contents
254: for my $value (split (/&/, $contents)) {
255: my ($name, $value) = split(/=/, $value);
256: $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
257: $self->{VARS}->{$name} = $value;
258: }
259:
1.3 bowersj2 260: $file->close();
261: } else {
262: # Only valid if we're just starting.
263: if ($self->{STATE} ne 'START') {
264: return undef;
265: }
266: # Must create the storage
267: $self->{TOKEN} = md5_hex($ENV{'user.name'} . $ENV{'user.domain'} .
268: time() . rand());
269: $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN});
270: }
271:
272: # OK, we now have our persistent storage.
273:
274: if (defined $ENV{"form.RETURN_PAGE"})
275: {
276: $self->{RETURN_PAGE} = $ENV{"form.RETURN_PAGE"};
277: }
278: else
279: {
280: $self->{RETURN_PAGE} = $ENV{REFERER};
281: }
282:
283: $self->{STATES} = {};
284: $self->{DONE} = 0;
285:
1.9 ! bowersj2 286: # Used by various helpers for various things; see lonparm.helper
! 287: # for an example.
! 288: $self->{DATA} = {};
! 289:
1.3 bowersj2 290: bless($self, $class);
291: return $self;
292: }
293:
294: # Private function; returns a string to construct the hidden fields
295: # necessary to have the helper track state.
296: sub _saveVars {
297: my $self = shift;
298: my $result = "";
299: $result .= '<input type="hidden" name="CURRENT_STATE" value="' .
300: HTML::Entities::encode($self->{STATE}) . "\" />\n";
301: $result .= '<input type="hidden" name="TOKEN" value="' .
302: $self->{TOKEN} . "\" />\n";
303: $result .= '<input type="hidden" name="RETURN_PAGE" value="' .
304: HTML::Entities::encode($self->{RETURN_PAGE}) . "\" />\n";
305:
306: return $result;
307: }
308:
309: # Private function: Create the querystring-like representation of the stored
310: # data to write to disk.
311: sub _varsInFile {
312: my $self = shift;
313: my @vars = ();
314: for my $key (keys %{$self->{VARS}}) {
315: push @vars, &Apache::lonnet::escape($key) . '=' .
316: &Apache::lonnet::escape($self->{VARS}->{$key});
317: }
318: return join ('&', @vars);
319: }
320:
1.5 bowersj2 321: # Use this to declare variables.
322: # FIXME: Document this
323: sub declareVar {
324: my $self = shift;
325: my $var = shift;
326:
327: if (!defined($self->{VARS}->{$var})) {
328: $self->{VARS}->{$var} = '';
329: }
330:
331: my $envname = 'form.' . $var . '.forminput';
332: if (defined($ENV{$envname})) {
333: $self->{VARS}->{$var} = $ENV{$envname};
334: }
335: }
336:
1.3 bowersj2 337: sub changeState {
338: my $self = shift;
339: $self->{STATE} = shift;
340: }
341:
342: sub registerState {
343: my $self = shift;
344: my $state = shift;
345:
346: my $stateName = $state->name();
347: $self->{STATES}{$stateName} = $state;
348: }
349:
350: # Done in four phases
351: # 1: Do the post processing for the previous state.
352: # 2: Do the preprocessing for the current state.
353: # 3: Check to see if state changed, if so, postprocess current and move to next.
354: # Repeat until state stays stable.
355: # 4: Render the current state to the screen as an HTML page.
356: sub display {
357: my $self = shift;
358:
359: my $result = "";
360:
361: # Phase 1: Post processing for state of previous screen (which is actually
362: # the "current state" in terms of the helper variables), if it wasn't the
363: # beginning state.
364: if ($self->{STATE} ne "START" || $ENV{"form.SUBMIT"} eq "Next ->") {
365: my $prevState = $self->{STATES}{$self->{STATE}};
366: $prevState->postprocess();
367: }
368:
369: # Note, to handle errors in a state's input that a user must correct,
370: # do not transition in the postprocess, and force the user to correct
371: # the error.
372:
373: # Phase 2: Preprocess current state
374: my $startState = $self->{STATE};
375: my $state = $self->{STATES}{$startState};
376:
377: # Error checking; it is intended that the developer will have
378: # checked all paths and the user can't see this!
379: if (!defined($state)) {
380: $result .="Error! The state ". $startState ." is not defined.";
381: return $result;
382: }
383: $state->preprocess();
384:
385: # Phase 3: While the current state is different from the previous state,
386: # keep processing.
387: while ( $startState ne $self->{STATE} )
388: {
389: $startState = $self->{STATE};
390: $state = $self->{STATES}{$startState};
391: $state->preprocess();
392: }
393:
394: # Phase 4: Display.
395: my $stateTitle = $state->title();
396: my $bodytag = &Apache::loncommon::bodytag("$self->{TITLE}",'','');
397:
398: $result .= <<HEADER;
399: <html>
400: <head>
401: <title>LON-CAPA Helper: $self->{TITLE}</title>
402: </head>
403: $bodytag
404: HEADER
405: if (!$state->overrideForm()) { $result.="<form name='wizform' method='GET'>"; }
406: $result .= <<HEADER;
407: <table border="0"><tr><td>
408: <h2><i>$stateTitle</i></h2>
409: HEADER
410:
411: if (!$state->overrideForm()) {
412: $result .= $self->_saveVars();
413: }
414: $result .= $state->render() . "<p> </p>";
415:
416: if (!$state->overrideForm()) {
417: $result .= '<center>';
418: if ($self->{STATE} ne $self->{START_STATE}) {
419: #$result .= '<input name="SUBMIT" type="submit" value="<- Previous" /> ';
420: }
421: if ($self->{DONE}) {
422: my $returnPage = $self->{RETURN_PAGE};
423: $result .= "<a href=\"$returnPage\">End Helper</a>";
424: }
425: else {
426: $result .= '<input name="back" type="button" ';
427: $result .= 'value="<- Previous" onclick="history.go(-1)" /> ';
428: $result .= '<input name="SUBMIT" type="submit" value="Next ->" />';
429: }
430: $result .= "</center>\n";
431: }
432:
1.5 bowersj2 433: foreach my $key (keys %{$self->{VARS}}) {
434: $result .= "|$key| -> " . $self->{VARS}->{$key} . "<br />";
435: }
436:
1.3 bowersj2 437: $result .= <<FOOTER;
438: </td>
439: </tr>
440: </table>
441: </form>
442: </body>
443: </html>
444: FOOTER
445:
446: # Handle writing out the vars to the file
447: my $file = Apache::File->new('>'.$self->{FILENAME});
448: print $file $self->_varsInFile();
449:
450: return $result;
451: }
452:
453: 1;
454:
455: package Apache::lonhelper::state;
456:
457: # States bundle things together and are responsible for compositing the
1.4 bowersj2 458: # various elements together. It is not generally necessary for users to
459: # use the state object directly, so it is not perldoc'ed.
460:
461: # Basically, all the states do is pass calls to the elements and aggregate
462: # the results.
1.3 bowersj2 463:
464: sub new {
465: my $proto = shift;
466: my $class = ref($proto) || $proto;
467: my $self = {};
468:
469: $self->{NAME} = shift;
470: $self->{TITLE} = shift;
471: $self->{ELEMENTS} = [];
472:
473: bless($self, $class);
474:
475: $helper->registerState($self);
476:
477: return $self;
478: }
479:
480: sub name {
481: my $self = shift;
482: return $self->{NAME};
483: }
484:
485: sub title {
486: my $self = shift;
487: return $self->{TITLE};
488: }
489:
1.4 bowersj2 490: sub preprocess {
491: my $self = shift;
492: for my $element (@{$self->{ELEMENTS}}) {
493: $element->preprocess();
494: }
495: }
496:
1.6 bowersj2 497: # FIXME: Document that all postprocesses must return a true value or
498: # the state transition will be overridden
1.4 bowersj2 499: sub postprocess {
500: my $self = shift;
1.6 bowersj2 501:
502: # Save the state so we can roll it back if we need to.
503: my $originalState = $helper->{STATE};
504: my $everythingSuccessful = 1;
505:
1.4 bowersj2 506: for my $element (@{$self->{ELEMENTS}}) {
1.6 bowersj2 507: my $result = $element->postprocess();
508: if (!$result) { $everythingSuccessful = 0; }
509: }
510:
511: # If not all the postprocesses were successful, override
512: # any state transitions that may have occurred. It is the
513: # responsibility of the states to make sure they have
514: # error handling in that case.
515: if (!$everythingSuccessful) {
516: $helper->{STATE} = $originalState;
1.4 bowersj2 517: }
518: }
519:
520: sub overrideForm {
521: return 0;
522: }
523:
524: sub addElement {
525: my $self = shift;
526: my $element = shift;
527:
528: push @{$self->{ELEMENTS}}, $element;
529: }
530:
531: sub render {
532: my $self = shift;
533: my @results = ();
534:
535: for my $element (@{$self->{ELEMENTS}}) {
536: push @results, $element->render();
537: }
538: return join("\n", @results);
539: }
540:
541: 1;
542:
543: package Apache::lonhelper::element;
544: # Support code for elements
545:
546: =pod
547:
548: =head2 Element Base Class
549:
550: The Apache::lonhelper::element base class provides support methods for
551: the elements to use, such as a multiple value processer.
552:
553: B<Methods>:
554:
555: =over 4
556:
557: =item * process_multiple_choices(formName, varName): Process the form
558: element named "formName" and place the selected items into the helper
559: variable named varName. This is for things like checkboxes or
560: multiple-selection listboxes where the user can select more then
561: one entry. The selected entries are delimited by triple pipes in
1.5 bowersj2 562: the helper variables, like this:
563:
564: CHOICE_1|||CHOICE_2|||CHOICE_3
1.4 bowersj2 565:
566: =back
567:
568: =cut
569:
1.5 bowersj2 570: BEGIN {
1.7 bowersj2 571: &Apache::lonhelper::register('Apache::lonhelper::element',
572: ('nextstate'));
1.5 bowersj2 573: }
574:
1.4 bowersj2 575: # Because we use the param hash, this is often a sufficent
576: # constructor
577: sub new {
578: my $proto = shift;
579: my $class = ref($proto) || $proto;
580: my $self = $paramHash;
581: bless($self, $class);
582:
583: $self->{PARAMS} = $paramHash;
584: $self->{STATE} = $state;
585: $state->addElement($self);
586:
587: # Ensure param hash is not reused
588: $paramHash = {};
589:
590: return $self;
591: }
592:
1.5 bowersj2 593: sub start_nextstate {
594: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
595:
596: if ($target ne 'helper') {
597: return '';
598: }
599:
600: $paramHash->{NEXTSTATE} = &Apache::lonxml::get_all_text('/nextstate',
601: $parser);
602: return '';
603: }
604:
605: sub end_nextstate { return ''; }
606:
1.4 bowersj2 607: sub preprocess {
608: return 1;
609: }
610:
611: sub postprocess {
612: return 1;
613: }
614:
615: sub render {
616: return '';
617: }
618:
1.3 bowersj2 619: sub process_multiple_choices {
620: my $self = shift;
621: my $formname = shift;
622: my $var = shift;
623:
624: my $formvalue = $ENV{'form.' . $formname};
625: if ($formvalue) {
1.5 bowersj2 626: # Must extract values from querystring directly, as there
1.3 bowersj2 627: # may be more then one.
628: my @values;
1.5 bowersj2 629: for my $formparam (split (/&/, $ENV{QUERY_STRING})) {
1.3 bowersj2 630: my ($name, $value) = split(/=/, $formparam);
631: if ($name ne $formname) {
632: next;
633: }
634: $value =~ tr/+/ /;
635: $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
636: push @values, $value;
637: }
1.5 bowersj2 638: $helper->{VARS}->{$var} = join('|||', @values);
1.3 bowersj2 639: }
640:
641: return;
642: }
643:
1.4 bowersj2 644: 1;
645:
646: package Apache::lonhelper::message;
647:
648: =pod
649:
650: =head2 Element: message
651:
652: Message elements display the contents of their <message_text> tags, and
1.5 bowersj2 653: transition directly to the state in the <nextstate> tag. Example:
1.4 bowersj2 654:
655: <message>
1.5 bowersj2 656: <nextstate>GET_NAME</nextstate>
1.4 bowersj2 657: <message_text>This is the <b>message</b> the user will see,
658: <i>HTML allowed</i>.</message_text>
659: </message>
660:
1.5 bowersj2 661: This will display the HTML message and transition to the <nextstate> if
1.7 bowersj2 662: given. The HTML will be directly inserted into the helper, so if you don't
1.4 bowersj2 663: want text to run together, you'll need to manually wrap the <message_text>
664: in <p> tags, or whatever is appropriate for your HTML.
665:
1.5 bowersj2 666: Message tags do not add in whitespace, so if you want it, you'll need to add
667: it into states. This is done so you can inline some elements, such as
668: the <date> element, right between two messages, giving the appearence that
669: the <date> element appears inline. (Note the elements can not be embedded
670: within each other.)
671:
1.4 bowersj2 672: This is also a good template for creating your own new states, as it has
673: very little code beyond the state template.
674:
675: =cut
676:
677: no strict;
678: @ISA = ("Apache::lonhelper::element");
679: use strict;
680:
681: BEGIN {
1.7 bowersj2 682: &Apache::lonhelper::register('Apache::lonhelper::message',
1.5 bowersj2 683: ('message', 'message_text'));
1.3 bowersj2 684: }
685:
1.5 bowersj2 686: sub new {
687: my $ref = Apache::lonhelper::element->new();
688: bless($ref);
689: }
1.4 bowersj2 690:
691: # CONSTRUCTION: Construct the message element from the XML
692: sub start_message {
693: return '';
1.3 bowersj2 694: }
695:
1.4 bowersj2 696: sub end_message {
697: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
698:
699: if ($target ne 'helper') {
700: return '';
701: }
702: Apache::lonhelper::message->new();
703: return '';
1.3 bowersj2 704: }
705:
1.5 bowersj2 706: sub start_message_text {
1.4 bowersj2 707: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
708:
709: if ($target ne 'helper') {
710: return '';
711: }
1.5 bowersj2 712:
713: $paramHash->{MESSAGE_TEXT} = &Apache::lonxml::get_all_text('/message_text',
714: $parser);
715: }
1.3 bowersj2 716:
1.5 bowersj2 717: sub end_message_text { return 1; }
718:
719: sub render {
720: my $self = shift;
721:
722: return $self->{MESSAGE_TEXT};
723: }
724: # If a NEXTSTATE was given, switch to it
725: sub postprocess {
726: my $self = shift;
727: if (defined($self->{NEXTSTATE})) {
728: $helper->changeState($self->{NEXTSTATE});
729: }
1.6 bowersj2 730:
731: return 1;
1.5 bowersj2 732: }
733: 1;
734:
735: package Apache::lonhelper::choices;
736:
737: =pod
738:
739: =head2 Element: choices
740:
741: Choice states provide a single choice to the user as a text selection box.
742: A "choice" is two pieces of text, one which will be displayed to the user
743: (the "human" value), and one which will be passed back to the program
744: (the "computer" value). For instance, a human may choose from a list of
745: resources on disk by title, while your program wants the file name.
746:
747: <choices> takes an attribute "variable" to control which helper variable
748: the result is stored in.
749:
750: <choices> takes an attribute "multichoice" which, if set to a true
751: value, will allow the user to select multiple choices.
752:
753: B<SUB-TAGS>
754:
755: <choices> can have the following subtags:
756:
757: =over 4
758:
759: =item * <nextstate>state_name</nextstate>: If given, this will cause the
760: choice element to transition to the given state after executing. If
761: this is used, do not pass nextstates to the <choice> tag.
762:
763: =item * <choice />: If the choices are static,
764: this element will allow you to specify them. Each choice
765: contains attribute, "computer", as described above. The
766: content of the tag will be used as the human label.
767: For example,
768: <choice computer='234-12-7312'>Bobby McDormik</choice>.
769:
770: <choice> may optionally contain a 'nextstate' attribute, which
771: will be the state transisitoned to if the choice is made, if
772: the choice is not multichoice.
773:
774: =back
775:
776: To create the choices programmatically, either wrap the choices in
777: <condition> tags (prefered), or use an <exec> block inside the <choice>
778: tag. Store the choices in $state->{CHOICES}, which is a list of list
779: references, where each list has three strings. The first is the human
780: name, the second is the computer name. and the third is the option
781: next state. For example:
782:
783: <exec>
784: for (my $i = 65; $i < 65 + 26; $i++) {
785: push @{$state->{CHOICES}}, [chr($i), $i, 'next'];
786: }
787: </exec>
788:
789: This will allow the user to select from the letters A-Z (in ASCII), while
790: passing the ASCII value back into the helper variables, and the state
791: will in all cases transition to 'next'.
792:
793: You can mix and match methods of creating choices, as long as you always
794: "push" onto the choice list, rather then wiping it out. (You can even
795: remove choices programmatically, but that would probably be bad form.)
796:
797: =cut
798:
799: no strict;
800: @ISA = ("Apache::lonhelper::element");
801: use strict;
802:
803: BEGIN {
1.7 bowersj2 804: &Apache::lonhelper::register('Apache::lonhelper::choices',
1.5 bowersj2 805: ('choice', 'choices'));
806: }
807:
808: sub new {
809: my $ref = Apache::lonhelper::element->new();
810: bless($ref);
811: }
812:
813: # CONSTRUCTION: Construct the message element from the XML
814: sub start_choices {
815: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
816:
817: if ($target ne 'helper') {
818: return '';
819: }
820:
821: # Need to initialize the choices list, so everything can assume it exists
822: $paramHash->{'variable'} = $token->[2]{'variable'};
823: $helper->declareVar($paramHash->{'variable'});
824: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
825: $paramHash->{CHOICES} = [];
826: return '';
827: }
828:
829: sub end_choices {
830: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
831:
832: if ($target ne 'helper') {
833: return '';
834: }
835: Apache::lonhelper::choices->new();
836: return '';
837: }
838:
839: sub start_choice {
840: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
841:
842: if ($target ne 'helper') {
843: return '';
844: }
845:
846: my $computer = $token->[2]{'computer'};
847: my $human = &Apache::lonxml::get_all_text('/choice',
848: $parser);
849: my $nextstate = $token->[2]{'nextstate'};
850: push @{$paramHash->{CHOICES}}, [$human, $computer, $nextstate];
851: return '';
852: }
853:
854: sub end_choice {
855: return '';
856: }
857:
858: sub render {
859: # START HERE: Replace this with correct choices code.
860: my $self = shift;
861: my $var = $self->{'variable'};
862: my $buttons = '';
863: my $result = '';
864:
865: if ($self->{'multichoice'}) {
1.6 bowersj2 866: $result .= <<SCRIPT;
1.5 bowersj2 867: <script>
868: function checkall(value) {
869: for (i=0; i<document.forms.wizform.elements.length; i++) {
870: document.forms.wizform.elements[i].checked=value;
871: }
872: }
873: </script>
874: SCRIPT
875: $buttons = <<BUTTONS;
876: <br />
877: <input type="button" onclick="checkall(true)" value="Select All" />
878: <input type="button" onclick="checkall(false)" value="Unselect All" />
1.6 bowersj2 879: <br />
1.5 bowersj2 880: BUTTONS
881: }
882:
883: if (defined $self->{ERROR_MSG}) {
1.6 bowersj2 884: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br />';
1.5 bowersj2 885: }
886:
887: $result .= $buttons;
1.6 bowersj2 888:
1.5 bowersj2 889: $result .= "<table>\n\n";
890:
891: my $type = "radio";
892: if ($self->{'multichoice'}) { $type = 'checkbox'; }
893: my $checked = 0;
894: foreach my $choice (@{$self->{CHOICES}}) {
895: $result .= "<tr>\n<td width='20'> </td>\n";
896: $result .= "<td valign='top'><input type='$type' name='$var.forminput'"
897: . "' value='" .
898: HTML::Entities::encode($choice->[1])
899: . "'";
900: if (!$self->{'multichoice'} && !$checked) {
901: $result .= " checked ";
902: $checked = 1;
903: }
904: $result .= "/></td><td> " . $choice->[0] . "</td></tr>\n";
905: }
906: $result .= "</table>\n\n\n";
907: $result .= $buttons;
908:
909: return $result;
910: }
911:
912: # If a NEXTSTATE was given or a nextstate for this choice was
913: # given, switch to it
914: sub postprocess {
915: my $self = shift;
916: my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};
917:
1.6 bowersj2 918: if (!$chosenValue) {
919: $self->{ERROR_MSG} = "You must choose one or more choices to" .
920: " continue.";
921: return 0;
922: }
923:
924: if ($self->{'multichoice'}) {
925: $self->process_multiple_choices($self->{'variable'}.'.forminput',
926: $self->{'variable'});
927: }
928:
1.5 bowersj2 929: if (defined($self->{NEXTSTATE})) {
930: $helper->changeState($self->{NEXTSTATE});
931: }
932:
933: foreach my $choice (@{$self->{CHOICES}}) {
934: if ($choice->[1] eq $chosenValue) {
935: if (defined($choice->[2])) {
936: $helper->changeState($choice->[2]);
937: }
938: }
939: }
1.6 bowersj2 940: return 1;
1.5 bowersj2 941: }
942: 1;
943:
944: package Apache::lonhelper::date;
945:
946: =pod
947:
948: =head2 Element: date
949:
950: Date elements allow the selection of a date with a drop down list.
951:
952: Date elements can take two attributes:
953:
954: =over 4
955:
956: =item * B<variable>: The name of the variable to store the chosen
957: date in. Required.
958:
959: =item * B<hoursminutes>: If a true value, the date will show hours
960: and minutes, as well as month/day/year. If false or missing,
961: the date will only show the month, day, and year.
962:
963: =back
964:
965: Date elements contain only an option <nextstate> tag to determine
966: the next state.
967:
968: Example:
969:
970: <date variable="DUE_DATE" hoursminutes="1">
971: <nextstate>choose_why</nextstate>
972: </date>
973:
974: =cut
975:
976: no strict;
977: @ISA = ("Apache::lonhelper::element");
978: use strict;
979:
980: use Time::localtime;
981:
982: BEGIN {
1.7 bowersj2 983: &Apache::lonhelper::register('Apache::lonhelper::date',
1.5 bowersj2 984: ('date'));
985: }
986:
987: # Don't need to override the "new" from element
988: sub new {
989: my $ref = Apache::lonhelper::element->new();
990: bless($ref);
991: }
992:
993: my @months = ("January", "February", "March", "April", "May", "June", "July",
994: "August", "September", "October", "November", "December");
995:
996: # CONSTRUCTION: Construct the message element from the XML
997: sub start_date {
998: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
999:
1000: if ($target ne 'helper') {
1001: return '';
1002: }
1003:
1004: $paramHash->{'variable'} = $token->[2]{'variable'};
1005: $helper->declareVar($paramHash->{'variable'});
1006: $paramHash->{'hoursminutes'} = $token->[2]{'hoursminutes'};
1007: }
1008:
1009: sub end_date {
1010: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1011:
1012: if ($target ne 'helper') {
1013: return '';
1014: }
1015: Apache::lonhelper::date->new();
1016: return '';
1017: }
1018:
1019: sub render {
1020: my $self = shift;
1021: my $result = "";
1022: my $var = $self->{'variable'};
1023:
1024: my $date;
1025:
1026: # Default date: The current hour.
1027: $date = localtime();
1028: $date->min(0);
1029:
1030: if (defined $self->{ERROR_MSG}) {
1031: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1032: }
1033:
1034: # Month
1035: my $i;
1036: $result .= "<select name='${var}month'>\n";
1037: for ($i = 0; $i < 12; $i++) {
1038: if ($i == $date->mon) {
1039: $result .= "<option value='$i' selected>";
1040: } else {
1041: $result .= "<option value='$i'>";
1042: }
1043: $result .= $months[$i] . "</option>\n";
1044: }
1045: $result .= "</select>\n";
1046:
1047: # Day
1048: $result .= "<select name='${var}day'>\n";
1049: for ($i = 1; $i < 32; $i++) {
1050: if ($i == $date->mday) {
1051: $result .= '<option selected>';
1052: } else {
1053: $result .= '<option>';
1054: }
1055: $result .= "$i</option>\n";
1056: }
1057: $result .= "</select>,\n";
1058:
1059: # Year
1060: $result .= "<select name='${var}year'>\n";
1061: for ($i = 2000; $i < 2030; $i++) { # update this after 64-bit dates
1062: if ($date->year + 1900 == $i) {
1063: $result .= "<option selected>";
1064: } else {
1065: $result .= "<option>";
1066: }
1067: $result .= "$i</option>\n";
1068: }
1069: $result .= "</select>,\n";
1070:
1071: # Display Hours and Minutes if they are called for
1072: if ($self->{'hoursminutes'}) {
1073: # Build hour
1074: $result .= "<select name='${var}hour'>\n";
1075: $result .= "<option " . ($date->hour == 0 ? 'selected ':'') .
1076: " value='0'>midnight</option>\n";
1077: for ($i = 1; $i < 12; $i++) {
1078: if ($date->hour == $i) {
1079: $result .= "<option selected value='$i'>$i a.m.</option>\n";
1080: } else {
1081: $result .= "<option value='$i'>$i a.m</option>\n";
1082: }
1083: }
1084: $result .= "<option " . ($date->hour == 12 ? 'selected ':'') .
1085: " value='12'>noon</option>\n";
1086: for ($i = 13; $i < 24; $i++) {
1087: my $printedHour = $i - 12;
1088: if ($date->hour == $i) {
1089: $result .= "<option selected value='$i'>$printedHour p.m.</option>\n";
1090: } else {
1091: $result .= "<option value='$i'>$printedHour p.m.</option>\n";
1092: }
1093: }
1094:
1095: $result .= "</select> :\n";
1096:
1097: $result .= "<select name='${var}minute'>\n";
1098: for ($i = 0; $i < 60; $i++) {
1099: my $printedMinute = $i;
1100: if ($i < 10) {
1101: $printedMinute = "0" . $printedMinute;
1102: }
1103: if ($date->min == $i) {
1104: $result .= "<option selected>";
1105: } else {
1106: $result .= "<option>";
1107: }
1108: $result .= "$printedMinute</option>\n";
1109: }
1110: $result .= "</select>\n";
1111: }
1112:
1113: return $result;
1114:
1115: }
1116: # If a NEXTSTATE was given, switch to it
1117: sub postprocess {
1118: my $self = shift;
1119: my $var = $self->{'variable'};
1120: my $month = $ENV{'form.' . $var . 'month'};
1121: my $day = $ENV{'form.' . $var . 'day'};
1122: my $year = $ENV{'form.' . $var . 'year'};
1123: my $min = 0;
1124: my $hour = 0;
1125: if ($self->{'hoursminutes'}) {
1126: $min = $ENV{'form.' . $var . 'minute'};
1127: $hour = $ENV{'form.' . $var . 'hour'};
1128: }
1129:
1130: my $chosenDate = Time::Local::timelocal(0, $min, $hour, $day, $month, $year);
1131: # Check to make sure that the date was not automatically co-erced into a
1132: # valid date, as we want to flag that as an error
1133: # This happens for "Feb. 31", for instance, which is coerced to March 2 or
1134: # 3, depending on if it's a leapyear
1135: my $checkDate = localtime($chosenDate);
1136:
1137: if ($checkDate->mon != $month || $checkDate->mday != $day ||
1138: $checkDate->year + 1900 != $year) {
1139: $self->{ERROR_MSG} = "Can't use " . $months[$month] . " $day, $year as a "
1140: . "date because it doesn't exist. Please enter a valid date.";
1.6 bowersj2 1141: return 0;
1.5 bowersj2 1142: }
1143:
1144: $helper->{VARS}->{$var} = $chosenDate;
1145:
1146: if (defined($self->{NEXTSTATE})) {
1147: $helper->changeState($self->{NEXTSTATE});
1148: }
1.6 bowersj2 1149:
1150: return 1;
1.5 bowersj2 1151: }
1152: 1;
1153:
1154: package Apache::lonhelper::resource;
1155:
1156: =pod
1157:
1158: =head2 Element: resource
1159:
1160: <resource> elements allow the user to select one or multiple resources
1161: from the current course. You can filter out which resources they can view,
1162: and filter out which resources they can select. The course will always
1163: be displayed fully expanded, because of the difficulty of maintaining
1164: selections across folder openings and closings. If this is fixed, then
1165: the user can manipulate the folders.
1166:
1167: <resource> takes the standard variable attribute to control what helper
1168: variable stores the results. It also takes a "multichoice" attribute,
1169: which controls whether the user can select more then one resource.
1170:
1171: B<SUB-TAGS>
1172:
1173: =over 4
1174:
1175: =item * <filterfunc>: If you want to filter what resources are displayed
1176: to the user, use a filter func. The <filterfunc> tag should contain
1177: Perl code that when wrapped with "sub { my $res = shift; " and "}" is
1178: a function that returns true if the resource should be displayed,
1179: and false if it should be skipped. $res is a resource object.
1180: (See Apache::lonnavmaps documentation for information about the
1181: resource object.)
1182:
1183: =item * <choicefunc>: Same as <filterfunc>, except that controls whether
1184: the given resource can be chosen. (It is almost always a good idea to
1185: show the user the folders, for instance, but you do not always want to
1186: let the user select them.)
1187:
1188: =item * <nextstate>: Standard nextstate behavior.
1189:
1190: =item * <valuefunc>: This function controls what is returned by the resource
1191: when the user selects it. Like filterfunc and choicefunc, it should be
1192: a function fragment that when wrapped by "sub { my $res = shift; " and
1193: "}" returns a string representing what you want to have as the value. By
1194: default, the value will be the resource ID of the object ($res->{ID}).
1195:
1196: =back
1197:
1198: =cut
1199:
1200: no strict;
1201: @ISA = ("Apache::lonhelper::element");
1202: use strict;
1203:
1204: BEGIN {
1.7 bowersj2 1205: &Apache::lonhelper::register('Apache::lonhelper::resource',
1.5 bowersj2 1206: ('resource', 'filterfunc',
1207: 'choicefunc', 'valuefunc'));
1208: }
1209:
1210: sub new {
1211: my $ref = Apache::lonhelper::element->new();
1212: bless($ref);
1213: }
1214:
1215: # CONSTRUCTION: Construct the message element from the XML
1216: sub start_resource {
1217: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1218:
1219: if ($target ne 'helper') {
1220: return '';
1221: }
1222:
1223: $paramHash->{'variable'} = $token->[2]{'variable'};
1224: $helper->declareVar($paramHash->{'variable'});
1225: return '';
1226: }
1227:
1228: sub end_resource {
1229: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1230:
1231: if ($target ne 'helper') {
1232: return '';
1233: }
1234: if (!defined($paramHash->{FILTER_FUNC})) {
1235: $paramHash->{FILTER_FUNC} = sub {return 1;};
1236: }
1237: if (!defined($paramHash->{CHOICE_FUNC})) {
1238: $paramHash->{CHOICE_FUNC} = sub {return 1;};
1239: }
1240: if (!defined($paramHash->{VALUE_FUNC})) {
1241: $paramHash->{VALUE_FUNC} = sub {my $res = shift; return $res->{ID}; };
1242: }
1243: Apache::lonhelper::resource->new();
1.4 bowersj2 1244: return '';
1245: }
1246:
1.5 bowersj2 1247: sub start_filterfunc {
1248: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1249:
1250: if ($target ne 'helper') {
1251: return '';
1252: }
1253:
1254: my $contents = Apache::lonxml::get_all_text('/filterfunc',
1255: $parser);
1256: $contents = 'sub { my $res = shift; ' . $contents . '}';
1257: $paramHash->{FILTER_FUNC} = eval $contents;
1258: }
1259:
1260: sub end_filterfunc { return ''; }
1261:
1262: sub start_choicefunc {
1263: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1264:
1265: if ($target ne 'helper') {
1266: return '';
1267: }
1268:
1269: my $contents = Apache::lonxml::get_all_text('/choicefunc',
1270: $parser);
1271: $contents = 'sub { my $res = shift; ' . $contents . '}';
1272: $paramHash->{CHOICE_FUNC} = eval $contents;
1273: }
1274:
1275: sub end_choicefunc { return ''; }
1276:
1277: sub start_valuefunc {
1278: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1279:
1280: if ($target ne 'helper') {
1281: return '';
1282: }
1283:
1284: my $contents = Apache::lonxml::get_all_text('/valuefunc',
1285: $parser);
1286: $contents = 'sub { my $res = shift; ' . $contents . '}';
1287: $paramHash->{VALUE_FUNC} = eval $contents;
1288: }
1289:
1290: sub end_valuefunc { return ''; }
1291:
1292: # A note, in case I don't get to this before I leave.
1293: # If someone complains about the "Back" button returning them
1294: # to the previous folder state, instead of returning them to
1295: # the previous helper state, the *correct* answer is for the helper
1296: # to keep track of how many times the user has manipulated the folders,
1297: # and feed that to the history.go() call in the helper rendering routines.
1298: # If done correctly, the helper itself can keep track of how many times
1299: # it renders the same states, so it doesn't go in just this state, and
1300: # you can lean on the browser back button to make sure it all chains
1301: # correctly.
1302: # Right now, though, I'm just forcing all folders open.
1303:
1304: sub render {
1305: my $self = shift;
1306: my $result = "";
1307: my $var = $self->{'variable'};
1308: my $curVal = $helper->{VARS}->{$var};
1309:
1310: if (defined $self->{ERROR_MSG}) {
1311: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1312: }
1313:
1314: my $filterFunc = $self->{FILTER_FUNC};
1315: my $choiceFunc = $self->{CHOICE_FUNC};
1316: my $valueFunc = $self->{VALUE_FUNC};
1317:
1318: # Create the composite function that renders the column on the nav map
1319: # have to admit any language that lets me do this can't be all bad
1320: # - Jeremy (Pythonista) ;-)
1321: my $checked = 0;
1322: my $renderColFunc = sub {
1323: my ($resource, $part, $params) = @_;
1324:
1325: if (!&$choiceFunc($resource)) {
1326: return '<td> </td>';
1327: } else {
1328: my $col = "<td><input type='radio' name='${var}.forminput' ";
1329: if (!$checked) {
1330: $col .= "checked ";
1331: $checked = 1;
1332: }
1333: $col .= "value='" .
1334: HTML::Entities::encode(&$valueFunc($resource))
1335: . "' /></td>";
1336: return $col;
1337: }
1338: };
1339:
1340: $ENV{'form.condition'} = 1;
1341: $result .=
1342: &Apache::lonnavmaps::render( { 'cols' => [$renderColFunc,
1343: Apache::lonnavmaps::resource()],
1344: 'showParts' => 0,
1345: 'url' => $helper->{URL},
1346: 'filterFunc' => $filterFunc,
1347: 'resource_no_folder_link' => 1 }
1348: );
1349:
1350: return $result;
1351: }
1352:
1353: sub postprocess {
1354: my $self = shift;
1355: if (defined($self->{NEXTSTATE})) {
1356: $helper->changeState($self->{NEXTSTATE});
1357: }
1.6 bowersj2 1358:
1359: return 1;
1.5 bowersj2 1360: }
1361:
1362: 1;
1363:
1364: package Apache::lonhelper::student;
1365:
1366: =pod
1367:
1368: =head2 Element: student
1369:
1370: Student elements display a choice of students enrolled in the current
1371: course. Currently it is primitive; this is expected to evolve later.
1372:
1373: Student elements take two attributes: "variable", which means what
1374: it usually does, and "multichoice", which if true allows the user
1375: to select multiple students.
1376:
1377: =cut
1378:
1379: no strict;
1380: @ISA = ("Apache::lonhelper::element");
1381: use strict;
1382:
1383:
1384:
1385: BEGIN {
1.7 bowersj2 1386: &Apache::lonhelper::register('Apache::lonhelper::student',
1.5 bowersj2 1387: ('student'));
1388: }
1389:
1390: sub new {
1391: my $ref = Apache::lonhelper::element->new();
1392: bless($ref);
1393: }
1.4 bowersj2 1394:
1.5 bowersj2 1395: sub start_student {
1.4 bowersj2 1396: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1397:
1398: if ($target ne 'helper') {
1399: return '';
1400: }
1401:
1.5 bowersj2 1402: $paramHash->{'variable'} = $token->[2]{'variable'};
1403: $helper->declareVar($paramHash->{'variable'});
1404: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1405: }
1406:
1407: sub end_student {
1408: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1409:
1410: if ($target ne 'helper') {
1411: return '';
1412: }
1413: Apache::lonhelper::student->new();
1.3 bowersj2 1414: }
1.5 bowersj2 1415:
1416: sub render {
1417: my $self = shift;
1418: my $result = '';
1419: my $buttons = '';
1420:
1421: if ($self->{'multichoice'}) {
1422: $result = <<SCRIPT;
1423: <script>
1424: function checkall(value) {
1425: for (i=0; i<document.forms.wizform.elements.length; i++) {
1426: document.forms.wizform.elements[i].checked=value;
1427: }
1428: }
1429: </script>
1430: SCRIPT
1431: $buttons = <<BUTTONS;
1432: <br />
1433: <input type="button" onclick="checkall(true)" value="Select All" />
1434: <input type="button" onclick="checkall(false)" value="Unselect All" />
1435: <br />
1436: BUTTONS
1437: }
1438:
1439: if (defined $self->{ERROR_MSG}) {
1440: $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1441: }
1442:
1443: # Load up the students
1444: my $choices = &Apache::loncoursedata::get_classlist();
1445:
1446: my @keys = keys %{$choices};
1447:
1448: # Constants
1449: my $section = Apache::loncoursedata::CL_SECTION();
1450: my $fullname = Apache::loncoursedata::CL_FULLNAME();
1451:
1452: # Sort by: Section, name
1453: @keys = sort {
1454: if ($choices->{$a}->[$section] ne $choices->{$b}->[$section]) {
1455: return $choices->{$a}->[$section] cmp $choices->{$b}->[$section];
1456: }
1457: return $choices->{$a}->[$fullname] cmp $choices->{$b}->[$fullname];
1458: } @keys;
1459:
1460: my $type = 'radio';
1461: if ($self->{'multichoice'}) { $type = 'checkbox'; }
1462: $result .= "<table cellspacing='2' cellpadding='2' border='0'>\n";
1463: $result .= "<tr><td></td><td align='center'><b>Student Name</b></td>".
1464: "<td align='center'><b>Section</b></td></tr>";
1465:
1466: my $checked = 0;
1467: foreach (@keys) {
1468: $result .= "<tr><td><input type='$type' name='" .
1469: $self->{'variable'} . '.forminput' . "'";
1470:
1471: if (!$self->{'multichoice'} && !$checked) {
1472: $result .= " checked ";
1473: $checked = 1;
1474: }
1475: $result .=
1476: " value='" . HTML::Entities::encode($_)
1477: . "' /></td><td>"
1478: . HTML::Entities::encode($choices->{$_}->[$fullname])
1479: . "</td><td align='center'>"
1480: . HTML::Entities::encode($choices->{$_}->[$section])
1481: . "</td></tr>\n";
1482: }
1483:
1484: $result .= "</table>\n\n";
1485: $result .= $buttons;
1.4 bowersj2 1486:
1.5 bowersj2 1487: return $result;
1488: }
1489:
1.6 bowersj2 1490: sub postprocess {
1491: my $self = shift;
1492:
1493: my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
1494: if (!$result) {
1495: $self->{ERROR_MSG} = 'You must choose at least one student '.
1496: 'to continue.';
1497: return 0;
1498: }
1499:
1500: if ($self->{'multichoice'}) {
1501: $self->process_multiple_choices($self->{'variable'}.'.forminput',
1502: $self->{'variable'});
1503: }
1504: if (defined($self->{NEXTSTATE})) {
1505: $helper->changeState($self->{NEXTSTATE});
1506: }
1507:
1508: return 1;
1509: }
1510:
1.5 bowersj2 1511: 1;
1512:
1513: package Apache::lonhelper::files;
1514:
1515: =pod
1516:
1517: =head2 Element: files
1518:
1519: files allows the users to choose files from a given directory on the
1520: server. It is always multichoice and stores the result as a triple-pipe
1521: delimited entry in the helper variables.
1522:
1523: Since it is extremely unlikely that you can actually code a constant
1524: representing the directory you wish to allow the user to search, <files>
1525: takes a subroutine that returns the name of the directory you wish to
1526: have the user browse.
1527:
1528: files accepts the attribute "variable" to control where the files chosen
1529: are put. It accepts the attribute "multichoice" as the other attribute,
1530: defaulting to false, which if true will allow the user to select more
1531: then one choice.
1532:
1533: <files> accepts three subtags. One is the "nextstate" sub-tag that works
1534: as it does with the other tags. Another is a <filechoice> sub tag that
1535: is Perl code that, when surrounded by "sub {" and "}" will return a
1536: string representing what directory on the server to allow the user to
1537: choose files from. Finally, the <filefilter> subtag should contain Perl
1538: code that when surrounded by "sub { my $filename = shift; " and "}",
1539: returns a true value if the user can pick that file, or false otherwise.
1540: The filename passed to the function will be just the name of the file,
1541: with no path info.
1542:
1543: =cut
1544:
1545: no strict;
1546: @ISA = ("Apache::lonhelper::element");
1547: use strict;
1548:
1549: BEGIN {
1.7 bowersj2 1550: &Apache::lonhelper::register('Apache::lonhelper::files',
1551: ('files', 'filechoice', 'filefilter'));
1.5 bowersj2 1552: }
1553:
1554: sub new {
1555: my $ref = Apache::lonhelper::element->new();
1556: bless($ref);
1557: }
1558:
1559: sub start_files {
1560: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1561:
1562: if ($target ne 'helper') {
1563: return '';
1564: }
1565: $paramHash->{'variable'} = $token->[2]{'variable'};
1566: $helper->declareVar($paramHash->{'variable'});
1567: $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
1568: }
1569:
1570: sub end_files {
1571: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1572:
1573: if ($target ne 'helper') {
1574: return '';
1575: }
1576: if (!defined($paramHash->{FILTER_FUNC})) {
1577: $paramHash->{FILTER_FUNC} = sub { return 1; };
1578: }
1579: Apache::lonhelper::files->new();
1580: }
1581:
1582: sub start_filechoice {
1583: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1584:
1585: if ($target ne 'helper') {
1586: return '';
1587: }
1588: $paramHash->{'filechoice'} = Apache::lonxml::get_all_text('/filechoice',
1589: $parser);
1590: }
1591:
1592: sub end_filechoice { return ''; }
1593:
1594: sub start_filefilter {
1595: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1596:
1597: if ($target ne 'helper') {
1598: return '';
1599: }
1600:
1601: my $contents = Apache::lonxml::get_all_text('/filefilter',
1602: $parser);
1603: $contents = 'sub { my $filename = shift; ' . $contents . '}';
1604: $paramHash->{FILTER_FUNC} = eval $contents;
1605: }
1606:
1607: sub end_filefilter { return ''; }
1.3 bowersj2 1608:
1609: sub render {
1610: my $self = shift;
1.5 bowersj2 1611: my $result = '';
1612: my $var = $self->{'variable'};
1613:
1614: my $subdirFunc = eval('sub {' . $self->{'filechoice'} . '}');
1615: my $subdir = &$subdirFunc();
1616:
1617: my $filterFunc = $self->{FILTER_FUNC};
1618: my $buttons = '';
1619:
1620: if ($self->{'multichoice'}) {
1621: $result = <<SCRIPT;
1622: <script>
1623: function checkall(value) {
1624: for (i=0; i<document.forms.wizform.elements.length; i++) {
1625: ele = document.forms.wizform.elements[i];
1626: if (ele.type == "checkbox") {
1627: document.forms.wizform.elements[i].checked=value;
1628: }
1629: }
1630: }
1631: </script>
1632: SCRIPT
1633: my $buttons = <<BUTTONS;
1634: <br />
1635: <input type="button" onclick="checkall(true)" value="Select All" />
1636: <input type="button" onclick="checkall(false)" value="Unselect All" />
1637: <br />
1638: BUTTONS
1639: }
1640:
1641: # Get the list of files in this directory.
1642: my @fileList;
1643:
1644: # If the subdirectory is in local CSTR space
1645: if ($subdir =~ m|/home/([^/]+)/public_html|) {
1646: my $user = $1;
1647: my $domain = $Apache::lonnet::perlvar{'lonDefDomain'};
1648: @fileList = &Apache::lonnet::dirlist($subdir, $domain, $user, '');
1649: } else {
1650: # local library server resource space
1651: @fileList = &Apache::lonnet::dirlist($subdir, $ENV{'user.domain'}, $ENV{'user.name'}, '');
1652: }
1.3 bowersj2 1653:
1.5 bowersj2 1654: $result .= $buttons;
1655:
1.6 bowersj2 1656: if (defined $self->{ERROR_MSG}) {
1657: $result .= '<br /><font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
1658: }
1659:
1.5 bowersj2 1660: $result .= '<table border="0" cellpadding="1" cellspacing="1">';
1661:
1662: # Keeps track if there are no choices, prints appropriate error
1663: # if there are none.
1664: my $choices = 0;
1665: my $type = 'radio';
1666: if ($self->{'multichoice'}) {
1667: $type = 'checkbox';
1668: }
1669: # Print each legitimate file choice.
1670: for my $file (@fileList) {
1671: $file = (split(/&/, $file))[0];
1672: if ($file eq '.' || $file eq '..') {
1673: next;
1674: }
1675: my $fileName = $subdir .'/'. $file;
1676: if (&$filterFunc($file)) {
1677: $result .= '<tr><td align="right">' .
1678: "<input type='$type' name='" . $var
1679: . ".forminput' value='" . HTML::Entities::encode($fileName) .
1680: "'";
1681: if (!$self->{'multichoice'} && $choices == 0) {
1682: $result .= ' checked';
1683: }
1684: $result .= "/></td><td>" . $file . "</td></tr>\n";
1685: $choices++;
1686: }
1687: }
1688:
1689: $result .= "</table>\n";
1690:
1691: if (!$choices) {
1692: $result .= '<font color="#FF0000">There are no files available to select in this directory. Please go back and select another option.</font><br /><br />';
1693: }
1694:
1695: $result .= $buttons;
1696:
1697: return $result;
1.4 bowersj2 1698: }
1.5 bowersj2 1699:
1.4 bowersj2 1700: sub postprocess {
1701: my $self = shift;
1.6 bowersj2 1702: my $result = $ENV{'form.' . $self->{'variable'} . '.forminput'};
1703: if (!$result) {
1704: $self->{ERROR_MSG} = 'You must choose at least one file '.
1705: 'to continue.';
1706: return 0;
1707: }
1708:
1.5 bowersj2 1709: if ($self->{'multichoice'}) {
1710: $self->process_multiple_choices($self->{'variable'}.'.forminput',
1711: $self->{'variable'});
1712: }
1713: if (defined($self->{NEXTSTATE})) {
1714: $helper->changeState($self->{NEXTSTATE});
1.3 bowersj2 1715: }
1.6 bowersj2 1716:
1717: return 1;
1.3 bowersj2 1718: }
1.8 bowersj2 1719:
1720: 1;
1721:
1722: package Apache::lonhelper::general;
1723:
1724: =pod
1725:
1726: =head2 General-purpose tag: <exec>
1727:
1728: The contents of the exec tag are executed as Perl code, not inside a
1729: safe space, so the full range of $ENV and such is available. The code
1730: will be executed as a subroutine wrapped with the following code:
1731:
1732: "sub { my $helper = shift; my $state = shift;" and
1733:
1734: "}"
1735:
1736: The return value is ignored.
1737:
1738: $helper is the helper object. Feel free to add methods to the helper
1739: object to support whatever manipulation you may need to do (for instance,
1740: overriding the form location if the state is the final state; see
1741: lonparm.helper for an example).
1742:
1743: $state is the $paramHash that has currently been generated and may
1744: be manipulated by the code in exec. Note that the $state is not yet
1745: an actual state B<object>, it is just a hash, so do not expect to
1746: be able to call methods on it.
1747:
1748: =cut
1749:
1750: BEGIN {
1751: &Apache::lonhelper::register('Apache::lonhelper::general',
1752: 'exec', 'condition', 'clause');
1753: }
1754:
1755: sub start_exec {
1756: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1757:
1758: if ($target ne 'helper') {
1759: return '';
1760: }
1761:
1762: my $code = &Apache::lonxml::get_all_text('/exec', $parser);
1763:
1764: $code = eval ('sub { my $helper = shift; my $state = shift; ' .
1765: $code . "}");
1766: &$code($helper, $paramHash);
1767: }
1768:
1769: sub end_exec { return ''; }
1770:
1771: =pod
1772:
1773: =head2 General-purpose tag: <condition>
1774:
1775: The <condition> tag allows you to mask out parts of the helper code
1776: depending on some programatically determined condition. The condition
1777: tag contains a tag <clause> which contains perl code that when wrapped
1778: with "sub { my $helper = shift; my $state = shift; " and "}", returns
1779: a true value if the XML in the condition should be evaluated as a normal
1780: part of the helper, or false if it should be completely discarded.
1781:
1782: The <clause> tag must be the first sub-tag of the <condition> tag or
1783: it will not work as expected.
1784:
1785: =cut
1786:
1787: # The condition tag just functions as a marker, it doesn't have
1788: # to "do" anything. Technically it doesn't even have to be registered
1789: # with the lonxml code, but I leave this here to be explicit about it.
1790: sub start_condition { return ''; }
1791: sub end_condition { return ''; }
1792:
1793: sub start_clause {
1794: my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
1795:
1796: if ($target ne 'helper') {
1797: return '';
1798: }
1799:
1800: my $clause = Apache::lonxml::get_all_text('/clause', $parser);
1801: $clause = eval('sub { my $helper = shift; my $state = shift; '
1802: . $clause . '}');
1803: if (!&$clause($helper, $paramHash)) {
1804: # Discard all text until the /condition.
1805: &Apache::lonxml::get_all_text('/condition', $parser);
1806: }
1807: }
1808:
1809: sub end_clause { return ''; }
1.5 bowersj2 1810:
1.4 bowersj2 1811: 1;
1.3 bowersj2 1812:
1.1 bowersj2 1813: __END__
1.3 bowersj2 1814:
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