lib.php 44.8 KB
Newer Older
1
2
3
<?php
/**
 * Mahara: Electronic portfolio, weblog, resume builder and social networking
4
5
 * Copyright (C) 2006-2009 Catalyst IT Ltd and others; see:
 *                         http://wiki.mahara.org/Contributors
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @package    mahara
 * @subpackage import-leap
 * @author     Catalyst IT Ltd
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL
24
 * @copyright  (C) 2006-2009 Catalyst IT Ltd http://catalyst.net.nz
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
 *
 */

defined('INTERNAL') || die();

/**
 * Implements import of LEAP2A files
 *
 * For more documentation, please see:
 * http://wiki.mahara.org/index.php?title=Developer_Area/Import%2F%2FExport/LEAP_Import
 */
class PluginImportLeap extends PluginImport {

    private $xml = null;
    private $namespaces = array();
    private $strategylisting = array();
    private $loadmapping = array();
42
    private $coreloadmapping = array();
43
44
    private $artefactids = array();

45
46
    protected $persondataid = null;

47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
    protected $loglevel = 0;
    protected $logtargets = LOG_TARGET_ERRORLOG;
    protected $profile = false;

    private $snapshots = array();

    const LOG_LEVEL_STANDARD = 1;
    const LOG_LEVEL_VERBOSE  = 2;

    const NS_ATOM       = 'http://www.w3.org/2005/Atom';
    const NS_RDF        = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#';
    const NS_LEAP       = 'http://wiki.cetis.ac.uk/2009-03/LEAP2A_predicates#';
    const NS_LEAPTYPE   = 'http://wiki.cetis.ac.uk/2009-03/LEAP2A_types#';
    const NS_CATEGORIES = 'http://wiki.cetis.ac.uk/2009-03/LEAP2A_categories/';
    const NS_MAHARA     = 'http://wiki.mahara.org/Developer_Area/Import%2F%2FExport/LEAP_Extensions#';

63
64
65
    const XHTML_DIV       = '<div xmlns="http://www.w3.org/1999/xhtml">';
    const XHTML_DIV_EMPTY = '<div xmlns="http://www.w3.org/1999/xhtml"/>';

Nigel McNie's avatar
Nigel McNie committed
66
67
    const STRATEGY_IMPORT_AS_VIEW = 1;

68
69
70
71
72
73
74
75
76
77
78
    public static function validate_import_data($importdata) {
    }

    public function get($field) {
        if ($field == 'xml') {
            return $this->xml;
        }
        return parent::get($field);
    }

    public function process() {
79
80
        db_begin();

81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
        $data = $this->get('data');
        $filename = get_config('dataroot') . $data['filename'];
        $this->trace('Loading import from ' . $filename);
        $this->snapshot('begin');

        $options =
            LIBXML_COMPACT |    // Reported to greatly speed XML parsing
            LIBXML_NONET        // Disable network access - security check
        ;
        if (!$this->xml = simplexml_load_file($filename, 'SimpleXMLElement', $options)) {
            // TODO: bail out in a much nicer way...
            throw new ImportException($this, "FATAL: XML file is not well formed! Please consult Mahara's error log for more information");
        }
        $this->namespaces = array_flip($this->xml->getDocNamespaces());
        $this->registerXpathNamespaces($this->xml);
        $this->trace("Document loaded, entries: " . count($this->xml->entry));
        $this->snapshot('loaded XML');

        $this->ensure_document_valid();

        $this->create_strategy_listing();
        $this->snapshot('created strategy listing');
        $this->strategy_listing_to_load_mapping();
        $this->snapshot('converted strategy listing to load mapping');
        $this->import_from_load_mapping();
        $this->snapshot('imported data based on load mapping');
        $this->import_completed();

109
        db_commit();
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
    }

    private function ensure_document_valid() {
        // TODO: http://wiki.mahara.org/Developer_Area/Import%2f%2fExport/Import%3a_Implementation_Plan#beginning
        //
        // Do a bunch of checks that will ensure the feed is valid, and thus 
        // allow future code to make assumptions that the feed is valid

        // Things to check:
        // - all content src="X": make sure the src actually exists
        // - feed has a <feed> element with an <author> and <entry>s
        // - feed element has correct namespaces (keep in mind we need to be 
        // able to import raw ATOM feeds too)

        //throw new ImportException($this, "Import wasn't valid. TODO: error reporting");
125
126
127
128
129
130
131
132

        // Check all the namespaces we're gonna need are declared, and warn if 
        // they're not there
        foreach (array(self::NS_ATOM, self::NS_RDF, self::NS_LEAP, self::NS_LEAPTYPE, self::NS_CATEGORIES) as $ns) {
            if (!isset($this->namespaces[$ns])) {
                $this->trace("WARNING: Namespaces $ns wasn't declared - this will make importing data correctly difficult");
            }
        }
133
134
135
136
137
138
139
140
141
    }

    /**
     * http://wiki.mahara.org/Developer_Area/Import%2f%2fExport/Import%3a_Implementation_Plan#first_pass_-_get_scores_from_plugins_for_each_entry
     *
     * Each list of strategies for each entry should be sorted from highest to lowest score once this is done
     */
    private function create_strategy_listing() {
        $this->trace("-------------------------\ncreate_strategy_listing()");
142
143
144
145
146
147
148
149
150
151
152

        // First, try to establish whether there is an element representing the 
        // author of the feed
        // TODO: also check this element has the right leaptype (person)
        if (is_null($this->persondataid)) {
            $author = $this->get('xml')->xpath('//a:feed/a:author[1]');
            $author = $author[0];
            if (isset($author->uri) && $this->get_entry_by_id((string)$author->uri)) {
                $this->persondataid = (string)$author->uri;
            }
            else {
153
154
155
156
157
158
159
160
                $persondata = $this->get('xml')->xpath('//a:feed/a:entry/a:category[('
                    . $this->curie_xpath('@scheme', PluginImportLeap::NS_CATEGORIES, 'person_type#') . ') and @term="Self"]/../a:id');
                if (isset($persondata[0])) {
                    $this->persondataid = (string)$persondata[0][0];
                }
                else {
                    $this->persondataid = false;
                }
161
162
163
164
            }
        }

        // Generate strategy listing
165
166
167
168
169
        foreach ($this->xml->xpath('//a:feed/a:entry') as $entry) {
            $this->registerXpathNamespaces($entry);
            $entryid = (string)$entry->id;
            $this->trace(" * $entryid ({$entry->title})");

170
171
172
173
174
            if ($this->persondataid && $entryid == $this->persondataid) {
                // We don't offer this element to any plugin to be imported
                continue;
            }

175
            foreach (plugins_installed('artefact') as $plugin) {
176
177
178
179
180
181
182
183
184
185
                $plugin = $plugin->name;
                if (safe_require('import', 'leap/' . $plugin, 'lib.php', 'require_once', true)) {
                    $classname = 'LeapImport' . ucfirst($plugin);
                    if (!is_subclass_of($classname, 'LeapImportArtefactPlugin')) {
                        throw new SystemException("Class $classname does not extend LeapImportArtefactPlugin as it should");
                    }
                    $strategies = call_static_method($classname, 'get_import_strategies_for_entry', $entry, $this);
                    $this->trace("   artefact.$plugin strategies: " . count($strategies));
                    if ($strategies) {
                        $this->trace($strategies, self::LOG_LEVEL_VERBOSE);
Nigel McNie's avatar
Nigel McNie committed
186
187
188
189
190
191
192
193
194
195
                        foreach ($strategies as $strategy) {
                            // Verify they're in valid form
                            if (!array_key_exists('strategy', $strategy)
                                || !array_key_exists('score', $strategy)
                                || !array_key_exists('other_required_entries', $strategy)) {
                                throw new SystemException("$classname::get_import_strategies_for_entry returned a strategy missing "
                                    . "one or more of the strategy, score or other_required_entries keys");
                            }
                            $strategy['artefactplugin'] = $plugin;
                            $this->strategylisting[$entryid][] = $strategy;
196
197
198
199
200
                        }
                    }
                }
            }

Nigel McNie's avatar
Nigel McNie committed
201
202
203
204
205
206
207
208
209
210
            $strategies = $this->get_import_strategies_for_entry($entry);
            $this->trace("   core strategies: " . count($strategies));
            if ($strategies) {
                $this->trace($strategies, self::LOG_LEVEL_VERBOSE);
                foreach ($strategies as $strategy) {
                    $strategy['artefactplugin'] = null;
                    $this->strategylisting[$entryid][] = $strategy;
                }
            }

211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
            if (!isset($this->strategylisting[$entryid])) {
                $this->trace(" ** Could not find any strategies for $entryid **");
                // TODO: we might need to expose this information later
                continue;
            }

            // Sort by score descending
            usort($this->strategylisting[$entryid], create_function('$a, $b', 'return $a["score"] < $b["score"];'));
        }
        $this->trace('*** Strategy listing: ***');
        $this->trace($this->strategylisting);
    }

    /**
     * Converts a strategy listing into the "best" load mapping that can be 
     * gleaned from the strategy listing.
     *
     * The best mapping is decided by sorting the strategy listing by score and 
     * importing all entries on a first-met, first used basis. The algorithm is 
     * described at:
     * http://wiki.mahara.org/Developer_Area/Import%2f%2fExport/Import%3a_Implementation_Plan#non-interactive_import
     */
    private function strategy_listing_to_load_mapping() {
        $this->trace("----------------------------------\nstrategy_listing_to_load_mapping()");
        $usedlist = array();

        // Each entry has its strategies sorted from best to worst score, then 
        // we sort the entire list of entries by the best scores they have 
        // available. This is so we get the "best" plan for importing
        uasort($this->strategylisting, array($this, 'strategy_listing_sort'));
        $this->trace('*** Sorted strategy listing ***', self::LOG_LEVEL_VERBOSE);
        $this->trace($this->strategylisting, self::LOG_LEVEL_VERBOSE);

        // We're only interested in the first listing really. It's the strategy 
        // with the highest score for this entry. Most of the loop mechanics is 
        // so that if we choose to import an entry that requires other entries, 
        // we don't import those other entries separately as well.
        foreach($this->strategylisting as $entryid => $strategies) {
            foreach ($strategies as $strategydata) {
                $this->trace("entry: $entryid");
                if (in_array($entryid, $usedlist)) {
                    $this->trace(" * already in used list, skipped");
                    continue;
                }
                if (isset($strategydata['other_required_entries'])) {
                    foreach ($strategydata['other_required_entries'] as $otherentryid) {
                        if (in_array($otherentryid, $usedlist)) {
                            $this->trace(" * other required entry $otherentryid already in used list, skipped");
                            continue;
                        }
                    }
                }

                $this->trace(" * using strategy $strategydata[strategy] from plugin $strategydata[artefactplugin]");
265
266
267
268
269
270
                if ($strategydata['artefactplugin']) {
                    $this->loadmapping[$entryid] = $strategydata;
                }
                else {
                    $this->coreloadmapping[$entryid] = $strategydata;
                }
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286

                $usedlist[] = $entryid;

                if (isset($strategydata['other_required_entries'])) {
                    foreach ($strategydata['other_required_entries'] as $otherentryid) {
                        $usedlist[] = $otherentryid;
                    }
                }

                // We've found how we're going to import this entry now
                // TODO: we should check the next strategy here and see if it 
                // has the same score, if it does we should note that for later 
                // for debugging purposes
                break;
            }
        }
287
        $this->trace("*** Plugin load mapping: ***");
288
        $this->trace($this->loadmapping);
289
290
        $this->trace("*** Core load mapping: ***");
        $this->trace($this->coreloadmapping);
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
    }

    private function strategy_listing_sort($a, $b) {
        // NOTE: the strategy listing should already have the strategies for 
        // each entry sorted from highest to lowest score. If it doesn't, these 
        // two sorts fix that, but this should never happen.
        //usort($a, create_function('$a, $b', 'return $a["score"] < $b["score"];'));
        //usort($b, create_function('$a, $b', 'return $a["score"] < $b["score"];'));
        return $a[0]['score'] < $b[0]['score'];
    }

    /**
     * Import entries using our load mapping. See:
     * http://wiki.mahara.org/Developer_Area/Import%2f%2fExport/Import%3a_Implementation_Plan#second_pass.3a_load_all_entries_into_mahara_as_per_load_mapping
     */
    private function import_from_load_mapping() {
        $this->trace("--------------------------\nimport_from_load_mapping()");
        // TODO: do both usedlists as by key instead of by value for faster checks
        $usedlist = $loadedentries = array();
        uksort($this->loadmapping, create_function('$a, $b', 'return $a["score"] < $b["score"];'));
        foreach ($this->loadmapping as $entryid => $strategydata) {
            if (in_array($entryid, $usedlist)) {
                // TODO: what should we do in this case?
                $this->trace("WARNING: $entryid has already been imported as part of a previous entry");
                continue;
            }
            if (isset($strategydata['other_required_entries'])) {
                foreach ($strategydata['other_required_entries'] as $otherentryid) {
                    if (in_array($otherentryid, $usedlist)) {
                        $this->trace("WARNING: $entryid has already been imported as part of a previous entry");
                        continue(2);
                    }
                }
            }

326
327
328
329
330
331
332
333
334
            $this->trace("Importing $entryid using strategy $strategydata[strategy] of plugin $strategydata[artefactplugin]");
            safe_require('artefact', $strategydata['artefactplugin']);
            $entry = $this->get_entry_by_id($entryid);
            $classname = 'LeapImport' . ucfirst($strategydata['artefactplugin']);
            // TODO: this throws ImportException if it can't be imported, need
            // to decide if this exception can bubble up or whether it should
            // be caught here
            $artefactmapping = call_static_method($classname, 'import_using_strategy',
                $entry, $this, $strategydata['strategy'], $strategydata['other_required_entries']);
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351

            if (!is_array($artefactmapping)) {
                throw new SystemException("import_from_load_mapping(): $classname::import_using_strategy has not return a list");
            }

            $this->artefactids = array_merge($this->artefactids, $artefactmapping);

            $usedlist[] = $entryid;
            if (isset($strategydata['other_required_entries'])) {
                foreach ($strategydata['other_required_entries'] as $otherentryid) {
                    $usedlist[] = $otherentryid;
                }
            }

            $loadedentries[] = $entryid;
        }

352
353
        // Give plugins a chance to import stuff about the feed author from the 
        // persondata entry
354
355
        // TODO: this should return an artefact mapping so things can create 
        // links to profile fields, but nothing actually needs it yet
356
357
        foreach (plugins_installed('artefact') as $plugin) {
            $classname = 'LeapImport' . ucfirst($plugin->name);
358
359
360
            if (method_exists($classname, 'import_author_data')) {
                call_static_method($classname, 'import_author_data', $this, $this->persondataid);
            }
361
        }
362
363
364
365
366

        // Now all artefacts are loaded, allow each plugin to load 
        // relationships for them if they need to
        foreach ($loadedentries as $entryid) {
            $strategydata = $this->loadmapping[$entryid];
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
            $classname = 'LeapImport' . ucfirst($strategydata['artefactplugin']);
            $entry = $this->get_entry_by_id($entryid);
            call_static_method($classname, 'setup_relationships',
                $entry, $this, $strategydata['strategy'], $strategydata['other_required_entries']);
        }

        // Now import views
        foreach ($this->coreloadmapping as $entryid => $strategydata) {
            if (in_array($entryid, $usedlist)) {
                $this->trace("WARNING: $entryid has already been imported as part of a previous entry");
                continue;
            }
            if (isset($strategydata['other_required_entries'])) {
                foreach ($strategydata['other_required_entries'] as $otherentryid) {
                    if (in_array($otherentryid, $usedlist)) {
                        $this->trace("WARNING: $entryid has already been imported as part of a previous entry");
                        continue(2);
                    }
                }
Nigel McNie's avatar
Nigel McNie committed
386
            }
387
388
389
390
391
392
393
394
395
396
397
398
399

            $this->trace("Importing $entryid using the core");
            $entry = $this->get_entry_by_id($entryid);
            $this->import_using_strategy($entry, $strategydata['strategy'], $strategydata['other_required_entries']);

            $usedlist[] = $entryid;
            if (isset($strategydata['other_required_entries'])) {
                foreach ($strategydata['other_required_entries'] as $otherentryid) {
                    $usedlist[] = $otherentryid;
                }
            }

            $loadedentries[] = $entryid;
400
401
402
403
404
405
406
        }
    }

    private function import_completed() {
        $this->trace("------------------\nimport_completed()");

        unset($this->loadmapping);
407
        unset($this->coreloadmapping);
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
        unset($this->strategylisting);
        unset($this->xpath);
        unset($this->dom);
        $this->snapshot('end');

        if ($this->profile) {
            $this->trace("k: abstime\ttime\tmemafter\tmemdiff");
            $firstdata = $lastdata = $this->snapshots['begin'];
            $i = 0;
            foreach ($this->snapshots as $identifier => $data) {
                $i++;
                $timetaken = $data['time'] - $lastdata['time'];
                $abstime   = $data['time'] - $firstdata['time'];
                $memoryafter = $data['ram'] / 1024;
                $memorygrowth = ($data['ram'] - $lastdata['ram']) / 1024;
                $this->trace(sprintf("$i: %.3f\t%.3f\t%.3fK\t%8.3fK", $abstime, $timetaken, $memoryafter, $memorygrowth));
                $lastdata = $data;
            }

            $i = 0;
            foreach (array_keys($this->snapshots) as $identifier) {
                $i++;
                $this->trace("$i = $identifier");
            }
            $this->trace("abstime = time after beginning step of import that this step completed\n"
                . "time = time taken to complete this step\n"
                . "memafter = script memory usage after this step\n"
                . "memdiff = difference in memory usage compared with the last step");
        }
    }

    /**
     * Logs a message for debugging purposes
     *
     * The user can configure the amount of logging, and where it goes, by 
     * setting the 'loglevel' and 'logtargets' fields.
     *
     * loglevel is one of {0, PluginImportLeap::LOG_LEVEL_STANDARD, PluginImportLeap::LOG_LEVEL_VERBOSE}
     * logtargets is one of the LOG_TARGET_* constants
     *
     * @param string $message The message to log
     * @param int    $level   The level at which to log this error
     */
    public function trace($message, $level=self::LOG_LEVEL_STANDARD) {
        if ($level <= $this->loglevel) {
            // Use our logging system temporarily, which provides us with 
            // access to its nice features. We use log_message instead of
            // log_debug because that will retain the the line/file where 
            // trace() was called, rather than saying all of the messages came 
            // from trace() itself
            global $CFG;
            $old = $CFG->log_dbg_targets;
            $CFG->log_dbg_targets = $this->logtargets;
            $file = $line = $trace = null;
            log_message ($message, LOG_LEVEL_DBG, true, true, $file, $line, $trace);
            $CFG->log_dbg_targets = $old;
        }
    }

    private function snapshot($identifier) {
        if ($this->profile) {
            $this->snapshots[$identifier] = array(
                'time' => microtime(true),
                'ram'  => memory_get_usage(), // TODO: http://php.net/memory_get_usage suggests this isn't available everywhere
            );
        }
    }

Nigel McNie's avatar
Nigel McNie committed
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
    /**
     * Given an entry, should return a list of the possible ways that it could 
     * be imported by the core.
     *
     * The core handles View importing, so this method looks for entries that 
     * could be converted into Views.
     *
     * For more information about this method, see 
     * {LeapImportArtefactPlugin::get_import_strategies_for_entry}
     *
     * @param SimpleXMLElement $entry
     */
    public function get_import_strategies_for_entry(SimpleXMLElement $entry) {
        if (self::is_rdf_type($entry, $this, 'selection')
            && self::is_correct_category_scheme($entry, $this, 'selection_type', 'Webpage')) {
            return array(array(
                'strategy' => self::STRATEGY_IMPORT_AS_VIEW,
                'score'    => 100,
                'other_required_entries' => array(),
            ));
        }
        return array();
    }

    /**
     */
    public function import_using_strategy(SimpleXMLElement $entry, $strategy, array $otherentries) {
        $artefactmapping = array();
        switch ($strategy) {
        case self::STRATEGY_IMPORT_AS_VIEW:
            require_once('view.php');

508
            if (!$this->import_entry_as_mahara_view($entry)) {
509
510
511
                // Not a Mahara view, just do basic import
                $this->trace('Not a Mahara view, doing basic import', self::LOG_LEVEL_VERBOSE);

512
513
514
515
516
                $viewdata = array(
                    'title'       => (string)$entry->title,
                    'description' => (string)$entry->summary,
                    'type'        => 'portfolio', // TODO
                    'layout'      => null, // TODO
Nigel McNie's avatar
Nigel McNie committed
517
                    'tags'        => self::get_entry_tags($entry),
518
519
520
521
522
523
524
525
526
527
528
529
                    'numcolumns'  => 1,
                    'ownerformat' => FORMAT_NAME_DISPLAYNAME, // TODO
                    'owner'       => $this->get('usr'),
                );
                if ($published = strtotime((string)$entry->published)) {
                    $viewdata['ctime'] = $published;
                }
                if ($updated = strtotime((string)$entry->updated)) {
                    $viewdata['mtime'] = $updated;
                }

                $view = View::create($viewdata, $this->get('usr'));
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544

                safe_require('blocktype', 'textbox');
                $bi = new BlockInstance(0,
                    array(
                        'blocktype'  => 'textbox',
                        'title'      => '',
                        'column'     => 1,
                        'order'      => 1,
                        'configdata' => array(
                            'text' => self::get_entry_content($entry, $this),
                        ),
                    )
                );
                $view->addblockinstance($bi);
            }
Nigel McNie's avatar
Nigel McNie committed
545
546
            break;
        default:
547
            throw new ImportException($this, 'TODO: get_string: unknown strategy chosen for importing entry');
Nigel McNie's avatar
Nigel McNie committed
548
549
550
551
        }
        return $artefactmapping;
    }

552
553
554
    /**
     * Attempts to import an entry as a mahara view
     *
555
556
557
     * We look for custom mahara namespaced tags that explain the View 
     * structure. If they're present, we use them to create a View using that 
     * structure.
558
     *
559
560
561
562
     * This differs a bit from the LEAP2A specification, but we do so 
     * deliberately to get 100% compatibility with Mahara to Mahara exports. 
     * Other systems can also construct content in the right format to trigger 
     * Mahara to import things as a full view.
563
     *
564
     * If the mahara tags are not present, we give up.
565
566
     *
     * @param SimpleXMLElement $entry The entry to be imported
567
     * @return boolean Whether it could be imported.
568
     */
569
    private function import_entry_as_mahara_view(SimpleXMLElement $entry) {
570
        static $blocktypes_installed = null;
571
        $viewelement = $entry->xpath('mahara:view[1]');
572

573
574
        if (count($viewelement) != 1) {
            // This isn't a Mahara view
575
576
577
            return false;
        }

578
579
580
581
582
583
584
585
        $columns = $entry->xpath('mahara:view[1]/mahara:column');
        $columncount = count($columns);
        if ($columncount < 1 || $columncount > 5) {
            // Whoops, invalid number of columns
            $this->trace("Invalid number of columns specified for potential view {$entry->id}, falling back to standard import", self::LOG_LEVEL_VERBOSE);
            return false;
        }

586
587
588
589
590
        $config = array(
            'title'       => (string)$entry->title,
            'description' => (string)$entry->summary,
            'type'        => 'portfolio', // TODO
            'layout'      => null, // TODO
Nigel McNie's avatar
Nigel McNie committed
591
            'tags'        => self::get_entry_tags($entry),
592
593
594
            'numcolumns'  => $columncount,
            'ownerformat' => FORMAT_NAME_DISPLAYNAME, // TODO
        );
595
596
597
598
599

        $col = 1;
        foreach ($columns as $column) {
            $blockinstances = $column->xpath('mahara:blockinstance');
            $row = 1;
600
            $config['columns'][$col] = array();
601
602
603
604
605
606
607
608
609
610
611
612
613
614
            foreach ($blockinstances as $blockinstance) {
                $attrs = self::get_attributes($blockinstance, PluginImportLeap::NS_MAHARA);
                if (!isset($attrs['blocktype'])) {
                    $this->trace("  No mahara:blocktype attribute set for blockinstance at col $col, row $row: skipping");
                    continue;
                }
                $this->trace("  Found block with type {$attrs['blocktype']} at [$col][$row]", self::LOG_LEVEL_VERBOSE);

                if ($blocktypes_installed === null) {
                    $blocktypes_installed = array_map(create_function('$a', 'return $a->name;'), plugins_installed('blocktype'));
                }

                if (in_array($attrs['blocktype'], $blocktypes_installed)) {
                    $configelements = $blockinstance->xpath('mahara:*');
615
616
617
618
619
                    $config['columns'][$col][$row] = array(
                        'type'   => $attrs['blocktype'],
                        'title'  => $attrs['blocktitle'],
                        'config' => array()
                    );
620
                    foreach ($configelements as $element) {
621
                        $config['columns'][$col][$row]['config'][$element->getName()] = (string)$element;
622
623
                    }

624
                    $row++;
625
626
627
                }
                else {
                    $this->trace("  Ignoring unknown blocktype {$attrs['blocktype']}");
628
629
                }
            }
630
            $col++;
631
632
        }

633
634
635
636
637
638
639
640
641
642
643
        $view = View::import_from_config($config, $this->get('usr'));

        if ($published = strtotime((string)$entry->published)) {
            $view->set('ctime', $published);
        }
        if ($updated = strtotime((string)$entry->updated)) {
            $view->set('mtime', $updated);
        }
        $view->set('owner', $this->get('usr'));

        $view->commit();
644
        return true;
645
646
    }

647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
    /**
     * Register all namespaces on an element that have been declared on the 
     * document
     *
     * TODO: we should probably do this by examining $this->namespaces
     */
    public function registerXpathNamespaces(SimpleXMLElement $element) {
        $element->registerXpathNamespace('a', PluginImportLeap::NS_ATOM);
        $element->registerXpathNamespace('rdf', PluginImportLeap::NS_RDF);
        $element->registerXpathNamespace('mahara', PluginImportLeap::NS_MAHARA);
    }

    public function get_entry_by_id($entryid) {
        static $cache = array();
        if (isset($cache[$entryid])) {
            return $cache[$entryid];
        }
        // TODO: entryid injection? Probably not worth worrying about
        $matches = $this->xml->xpath("//a:feed/a:entry/a:id[.='$entryid']/..");
        // TODO: there had better be only one...
        $entry = $matches[0];
        if ($entry) {
            $this->registerXpathNamespaces($entry);
        }
        return ($cache[$entryid] = $entry);
    }

    public function get_artefactids_imported_by_entryid($entryid) {
        if (!isset($this->artefactids[$entryid])) {
            return null;
        }
        return $this->artefactids[$entryid];
    }

    /**
     * Returns xpath for an attribute matching a given curie
     *
     * See http://wiki.cetis.ac.uk/2009-03/LEAP2A_elements#Use_of_CURIEs
     *
     * @param string $attribute The attribute to match
     * @param string $namespace The namespace for the attribute value
     * @param string $term      The term for the attribute value
     * @return string
     */
    public function curie_xpath($attribute, $namespace, $term) {
        $xpath = '';
        if (isset($this->namespaces[$namespace])) {
            $abbreviation = $this->namespaces[$namespace];

            // Simple case
            $xpath .= $attribute . '="' . $abbreviation . ':' . $term . '" or ';
            // "correct" curie syntax has them surrounded by [ ]
            $xpath .= $attribute . '="[' . $abbreviation . ':' . $term . ']" or ';
        }

        // The full URL for the curie
        $xpath .= $attribute . '="' . $namespace . $term . '"';

        return $xpath;
    }

    /**
     * Returns whether a curie matches a given namespace/term, checking all 
     * allowed forms of the curie
     *
     * @param string $curie     The curie to check
     * @param string $namespace The namespace to check the curie against
     * @param string $term      The term to check the curie against
     * @return boolean
     */
    public function curie_equals($curie, $namespace, $term) {
        if (isset($this->namespaces[$namespace])) {
            $abbreviation = $this->namespaces[$namespace];
            return
                $curie == "$abbreviation:$term"
                || $curie == "[$abbreviation:$term]"
                || $curie == $namespace . $term;
        }

        return $curie == $namespace . $term;
    }

729
730
731
732
733
734
735
736
737
738
739
740
    /**
     * Returns whether an entry has the given RDF type
     *
     * This helper method should probably be replaced by the as yet unwritten 
     * get_rdf_type at some point, as it would be faster to get the type and do 
     * comparisons than call this multiple times.
     *
     * @param SimpleXMLElement $entry    The entry to check
     * $param PluginImportLeap $importer The importer
     * @param string $rdftype            The type to check for
     * @return boolean Whether the entry has the given RDF type
     */
741
    public static function is_rdf_type(SimpleXMLElement $entry, PluginImportLeap $importer, $rdftype) {
742
743
744
745
746
        $result = $entry->xpath('rdf:type['
            . $importer->curie_xpath('@rdf:resource', PluginImportLeap::NS_LEAPTYPE, $rdftype) . ']');
        return isset($result[0]) && $result[0] instanceof SimpleXMLElement;
    }

747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
    /**
     * Returns if the entry has the given term in the given category
     *
     * @param SimpleXMLElement $entry    The entry to check
     * $param PluginImportLeap $importer The importer
     * @param string $category           The category to look in. See http://wiki.cetis.ac.uk/2009-03/LEAP2A_categories
     * @param string $term               The term to look for (see the docs for the appropriate category)
     * @return boolean Whether the entry has the term in the category
     */
    public static function is_correct_category_scheme(SimpleXMLElement $entry, PluginImportLeap $importer, $category, $term) {
        $result = $entry->xpath('a:category[('
            . $importer->curie_xpath('@scheme', PluginImportLeap::NS_CATEGORIES, $category . '#') . ') and @term="' . $term . '"]');
        return isset($result[0]) && $result[0] instanceof SimpleXMLElement;
    }

762
    /**
Nigel McNie's avatar
Nigel McNie committed
763
764
765
     * Returns the <content> for a given entry, stripping off any transport 
     * encoding and respecting the content type.
     *
766
     * TODO: make sure we are rawurlencoding our file paths in our export
Nigel McNie's avatar
Nigel McNie committed
767
768
769
770
     *
     * @param SimpleXMLElement $entry   The entry to get the content for
     * @param PlugimImporLeap $importer The importer
     * @return string The content
771
772
773
774
775
776
777
778
779
780
781
782
783
784
     */
    public static function get_entry_content(SimpleXMLElement $entry, PluginImportLeap $importer) {
        // Entries have content, and that content can be of different types. So we want to make sure we grab it in the right type
        // - if it's xhtml, we need asXML(), plus removing the <content> tags
        // - if it's text, what do we need???
        $type = isset($entry->content['type']) ? (string)$entry->content['type'] : 'text';
        switch ($type) {
        case 'xhtml':
            if (isset($entry->content->div)) {
                // TODO: using asXML() gives us the content, but does things 
                // like squashing the space between <br and />. This might need 
                // to be "fixed" (turned back into browser-happy xhtml) if it 
                // causes problems.
                $content = (string)$entry->content->div->asXML();
785
                if (substr($content, 0, 42) == self::XHTML_DIV) {
786
787
788
                    $content = substr($content, 42, -6);
                    return $content;
                }
789
790
791
                else if (substr($content, 0, 43) == self::XHTML_DIV_EMPTY) {
                    return '';
                }
792
            }
793
            log_debug("ERROR: <content> tag for entry {$entry->id} declared to be type xhtml but didn't wrap its content in a div with xmlns=http://www.w3.org/1999/xhtml");
794
795
796
797

            $starttaglength = strlen('<content type="xhtml">');
            $endtaglength   = strlen('</content>');
            return substr((string)$entry->content->asXML(), $starttaglength, -$endtaglength);
798
        case 'html':
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
        case 'text':
            return (string)$entry->content;
        default:
            throw new SystemException("Unrecognised content type for entry '$entry->id'");
        }
    }

    public static function get_entry_tags(SimpleXMLElement $entry) {
        $tags = array();
        foreach ($entry->category as $category) {
            if (!isset($category['scheme'])) {
                if (isset($category['label'])) {
                    $tags[] = (string)$category['label'];
                }
                else {
                    $tags[] = (string)$category['term'];
                }
            }
        }
        return array_unique($tags);
    }

821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
    /**
     * Look for leap:date elements that are part of an entry (if any) and 
     * return the values we parse from them
     *
     * Returned in a structure like so:
     * array(
     *     'start' => array(
     *         'value' => 'w3c compliant date/time format, as allowed by LEAP2A',
     *         'label' => 'label attribute, which is a plaintext version of the date',
     *     ),
     *     'end' => array(
     *         'value' => 'maybe only the value is set on some elements',
     *     ),
     *     'target' => array(
     *         'label' => 'sometimes, only the label will be set'
     *     )
     * )
     *
     * The only keys in the return value are those allowed by the LEAP2A spec, 
     * and only if they exist on the entry.
     *
     * The values may have the 'value', 'label' or both keys, depending on what 
     * each element has.
     *
     * Try and use the 'value' first, if you have a choice. Quite a few places 
     * in Mahara currently just store dates as plaintext though.
     *
     * Spec reference: http://wiki.cetis.ac.uk/2009-03/LEAP2A_literals#date
     */
    public static function get_leap_dates(SimpleXMLElement $entry) {
        $dates = array();
        foreach (array('start', 'end', 'target') as $point) {
            $dateelement = $entry->xpath('leap:date[@leap:point="' . $point . '"]');
            if (count($dateelement) == 1) {
                $dateelement = $dateelement[0];
            }

            if ($dateelement instanceof SimpleXMLElement) {
                $date = (string)$dateelement;
                if ($date) {
                    $dates[$point]['value'] = $date;
                }

                // Parse for leap:label
                $leapattributes = array();
                foreach ($dateelement->attributes(PluginImportLeap::NS_LEAP) as $key => $value) {
                    $leapattributes[$key] = (string)$value;
                }
                if (isset($leapattributes['label'])) {
                    $dates[$point]['label'] = $leapattributes['label'];
                }
            }
        }
        return $dates;
    }

877
878
879
880
881
882
    /**
     * Waffer thin helper to grab all attributes in a namespace.
     *
     * It's often much easier to work with them in this form. SimpleXML doesn't 
     * provide a nice property to get at them with.
     *
883
884
885
     * @param SimpleXMLElement $element The element to get attributes from
     * @param string $ns                The namespace to get the attributes for
     * @return array                    The attributes in the namespace
886
887
888
889
890
891
892
893
894
     */
    public static function get_attributes(SimpleXMLElement $item, $ns) {
        $attributes = array();
        foreach ($item->attributes($ns) as $key => $value) {
            $attributes[$key] = (string)$value;
        }
        return $attributes;
    }

895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
}


/**
 * Base class for artefact plugin implementations of LEAP import
 *
 * Any artefact plugin wanting to implement import needs to extend this class 
 * in the file artefact/<plugin>/import/leap/lib.php.
 *
 * TODO: link to wiki docs for more info
 */
abstract class LeapImportArtefactPlugin {

    /**
     * Given an entry, should return a list of the possible ways that it could 
     * be imported by this plugin.
     *
     * The return result is in the form:
     * array(
     *     array(
     *         strategy => [strategy:int],
     *         score    => [score:int],
     *         other_required_entries => array(
     *             [entryid:string],
     *             [entryid:string],
     *             ...
     *         ),
     *     ),
     *     [...],
     * )
     *
     * This can be described as a list of strategies. Each strategy has a 
     * unique (to this class) identifier ([strategy:int]), a score, and a list 
     * of IDs of other entries required to implement this strategy.
     *
     * The strategy is just an identifier for the internal use of the class, to 
     * distinguish between strategies. Most implementors should define class 
     * constants for them, e.g.:
     *
     *     const STRATEGY_IMPORT_AS_FILE = 1;
     *     const STRATEGY_IMPORT_AS_FOLDER = 1;
     *
     * The score represents how well this strategy applies to this entry. 100 
     * is considered an extremely high score (use this for 'I think this is a 
     * perfect match' type strategies).
     *
     * The other required entries is a list of entries this strategy will 
     * require to be implemented. It's a list of entry IDs - a.k.a the contents 
     * of the <id> element of an <entry>.
     *
     * The return result is a list of strategies, which means that you can 
     * provide more than one if you think you have two possible matches. This 
     * method should return everything that is _possible_, even if it's not the 
     * best match, as the user may choose the less obvious method of importing 
     * for some reason.
     *
951
952
     * @param SimpleXMLElement $entry    The entry to find import strategies for
     * @param PluginImportLeap $importer The importer
953
954
     * @return array A list of strategies that could be used to import this entry
     */
955
    abstract public static function get_import_strategies_for_entry(SimpleXMLElement $entry, PluginImportLeap $importer);
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996

    /**
     * Converts an entry into the appropriate artefacts using the given 
     * strategy.
     *
     * The strategy will be one of ones this plugin previously said would be
     * possible for this entry. This method may throw an ImportException if it 
     * is not.
     *
     * This method is quite tied to get_import_strategies_for_entry: if that 
     * method exports a certain strategy (with a certain list of other required 
     * entries), then if that strategy is chosen, this method will be invoked 
     * with that strategy and that list of other required entries. HOWEVER, you 
     * cannot assume that both method calls will happen in the same request - a 
     * UI may be presented to the user to make them choose strategies in 
     * between these steps, for example. So don't store state between them!
     *
     * Regarding other entries: based on the previous statement, this class 
     * said it required them to import this entry, so they should be necessary 
     * to complete the import of the entry. Alternatively, perhaps you 
     * recognise that importing them makes no sense when you import this entry. 
     * But be aware that your class is denying these entries to other classes 
     * if you do this!
     *
     * This method should return a list of entry ID => (list of artefact IDs):
     *
     * array(
     *     [entryid:string] => array([artefactid:int], [artefactid:int], ...),
     *     [entryid:string] => array([artefactid:int], [artefactid:int], ...),
     *     ...
     * )
     *
     * This list informs the importer of how each entry was converted into 
     * artefact(s). Often, an entry will be converted into just one artefact, 
     * but there's no reason why it might not be convereted into more.
     *
     * This information is used by setup_relationships() hooks to work out how 
     * entries were converted to artefacts, so for example, files can be 
     * attached to blog posts even though the files and blog posts were 
     * imported by different plugins.
     *
997
998
999
1000
1001
1002
1003
1004
1005
     * @param SimpleXMLElement $entry    The entry to import
     * @param PluginImportLeap $importer The importer
     * @param int $strategy              The strategy to use (should be a class 
     *                                   constant on your class, see the documentation
     *                                   of get_import_strategies_for_entry for more
     *                                   information)
     * @param array $otherentries        A list of entry IDs that this class 
     *                                   previously said were required to import 
     *                                   the entry
1006
1007
1008
1009
     * @throws ImportException If the strategy is unrecognised
     * @return array A list describing what artefacts were created by the 
     *               import of each entry
     */
1010
    abstract public static function import_using_strategy(SimpleXMLElement $entry, PluginImportLeap $importer, $strategy, array $otherentries);
1011

1012
1013
1014
    /**
     * Gives plugins a chance to import author data
     */
1015
    public static function import_author_data(PluginImportLeap $importer, $persondataid) {
1016
1017
    }

1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
    /**
     * Gives plugins a chance to construct relationships between the newly 
     * created artefacts.
     *
     * This hook is optional. If implemented, plugins get access to the entries 
     * they imported, and the strategy they used to import them. It is 
     * guaranteed that all other plugins have created the artefacts they wanted 
     * to create, and implementors of this hook can use 
     * $importer->get_artefactids_imported_by_entryid to get access to the 
     * artefacts they need.
     *
     * This method has no return value.
     *
1031
1032
1033
1034
1035
1036
     * @param SimpleXMLElement $entry    The entry previously imported
     * @param PluginImportLeap $importer The importer
     * @param int $strategy              The strategy to use (should be a class 
     *                                   constant on your class, see the documentation
     *                                   of get_import_strategies_for_entry for more
     *                                   information)
1037
1038
1039
1040
1041
     * @param array $otherentries     A list of entry IDs that this class 
     *                                previously said were required to import 
     *                                the entry
     * @throws ImportException If the strategy is unrecognised
     */
1042
    public static function setup_relationships(SimpleXMLElement $entry, PluginImportLeap $importer, $strategy, array $otherentries) {
1043
1044
1045
1046
1047
    }

}

?>