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root / drupal7 / sites / all / modules / ctools / includes / context.inc @ 6e3ce7c2

1
<?php
2

    
3
/**
4
 * @file
5
 * Contains code related to the ctools system of 'context'.
6
 *
7
 * Context, originally from Panels, is a method of packaging objects into
8
 * a more generic bundle and providing a plugin system so that a UI can
9
 * take advantage of them. The idea is that the context objects
10
 * represent 'the context' that a given operation (usually a page view)
11
 * is operating in or on.
12
 *
13
 * For example, when viewing a page, the 'context' is a node object. When
14
 * viewing a user, the 'context' is a user object. Contexts can also
15
 * have related contexts. For example, when viewing a 'node' you may need
16
 * to know something about the node author. Therefore, the node author
17
 * is a related context.
18
 */
19

    
20
/**
21
 * The context object is largely a wrapper around some other object, with
22
 * an interface to finding out what is contained and getting to both
23
 * the object and information about the object.
24
 *
25
 * Each context object has its own information, but some things are very
26
 * common, such as titles, data, keywords, etc. In particulare, the 'type'
27
 * of the context is important.
28
 */
29
class ctools_context {
30
  /**
31
   * @var string|array
32
   *   A string naming this specific context type. The values 'any' and 'none'
33
   *   are special:
34
   *    - 'any': used in is_type() to match any other type.
35
   *    - 'none': used to signal the type is not defined.
36
   */
37
  public $type;
38

    
39
  /**
40
   * @var mixed
41
   *   The data payload for this context object.
42
   */
43
  public $data;
44

    
45
  /**
46
   * @var string
47
   *   The title of this object.
48
   */
49
  public $title;
50

    
51
  /**
52
   * @var string
53
   *   The title of the page if this object exists
54
   */
55
  public $page_title;
56

    
57
  /**
58
   * @var string
59
   *   The identifier (in the UI) of this object.
60
   */
61
  public $identifier;
62

    
63
  /**
64
   * @var
65
   */
66
  public $argument;
67

    
68
  /**
69
   * @var string
70
   */
71
  public $keyword;
72

    
73
  /**
74
   * @var
75
   */
76
  public $original_argument;
77

    
78
  /**
79
   * @var array
80
   */
81
  public $restrictions;
82

    
83
  /**
84
   * @var bool
85
   */
86
  public $empty;
87

    
88
  /**
89
   * The ctools_context constructor.
90
   *
91
   * @param string $type
92
   *   The type name of this context. Should be unique. Use the machine_name
93
   *   conventions: lowercase, short, underscores and no spaces.
94
   * @param mixed $data
95
   *   The data payload, if required for this context.
96
   */
97
  public function __construct($type = 'none', $data = NULL) {
98
    $this->type = $type;
99
    $this->data = $data;
100
    $this->title = t('Unknown context');
101
    $this->page_title = '';
102
    $this->identifier = '';
103
    $this->keyword = '';
104
    $this->restrictions = array();
105
    $this->empty = FALSE;
106
    // Other vars are NULL.
107
  }
108

    
109
  /**
110
   * Determine whether this object is of type @var $type .
111
   *
112
   * Both the internal value ($this->type) and the supplied value ($type) can
113
   * be a string or an array of strings, and if one or both are arrays the match
114
   * succeeds if at least one common element is found.
115
   *
116
   * Type names
117
   *
118
   * @param string|array $type
119
   *   'type' can be:
120
   *    - 'any' to match all types (this is true of the internal value too).
121
   *    - an array of type name strings, when more than one type is acceptable.
122
   *
123
   * @return bool
124
   *   True if the type matches, False otherwise.
125
   */
126
  public function is_type($type) {
127
    if ($type === 'any' || $this->type === 'any') {
128
      return TRUE;
129
    }
130

    
131
    $a = is_array($type) ? $type : array($type);
132
    $b = is_array($this->type) ? $this->type : array($this->type);
133
    return (bool) array_intersect($a, $b);
134
  }
135

    
136
  /**
137
   * Return the argument.
138
   *
139
   * @return mixed
140
   *   The value of $argument.
141
   */
142
  public function get_argument() {
143
    return $this->argument;
144
  }
145

    
146
  /**
147
   * Return the value of argument (or arg) variable as it was passed in.
148
   *
149
   * For example see ctools_plugin_load_function() and ctools_terms_context().
150
   *
151
   * @return mixed
152
   *   The original arg value.
153
   */
154
  public function get_original_argument() {
155
    if (!is_null($this->original_argument)) {
156
      return $this->original_argument;
157
    }
158
    return $this->argument;
159
  }
160

    
161
  /**
162
   * Return the keyword.
163
   *
164
   * @return mixed
165
   *   The value of $keyword.
166
   */
167
  public function get_keyword() {
168
    return $this->keyword;
169
  }
170

    
171
  /**
172
   * Return the identifier.
173
   *
174
   * @return mixed
175
   *   The value of $identifier.
176
   */
177
  public function get_identifier() {
178
    return $this->identifier;
179
  }
180

    
181
  /**
182
   * Return the title.
183
   *
184
   * @return mixed
185
   *   The value of $title.
186
   */
187
  public function get_title() {
188
    return $this->title;
189
  }
190

    
191
  /**
192
   * Return the page title.
193
   *
194
   * @return mixed
195
   *   The value of $page_title.
196
   */
197
  public function get_page_title() {
198
    return $this->page_title;
199
  }
200

    
201
}
202

    
203
/**
204
 * Used to create a method of comparing if a list of contexts
205
 * match a required context type.
206
 */
207
class ctools_context_required {
208
  /**
209
   * @var array
210
   *   Keyword strings associated with the context.
211
   */
212
  public $keywords;
213

    
214
  /**
215
   * If set, the title will be used in the selector to identify
216
   * the context. This is very useful when multiple contexts
217
   * are required to inform the user will be used for what.
218
   */
219
  public $title;
220

    
221
  /**
222
   * Test to see if this context is required.
223
   */
224
  public $required = TRUE;
225

    
226
  /**
227
   * If TRUE, skip the check in ctools_context_required::select()
228
   * for contexts whose names may have changed.
229
   */
230
  public $skip_name_check = FALSE;
231

    
232
  /**
233
   * The ctools_context_required constructor.
234
   *
235
   * Note: Constructor accepts a variable number of arguments, with optional
236
   * type-dependent args at the end of the list and one required argument,
237
   * the title. Note in particular that skip_name_check MUST be passed in as
238
   * a boolean (and not, for example, as an integer).
239
   *
240
   * @param string $title
241
   *   The title of the context for use in UI selectors when multiple contexts
242
   *   qualify.
243
   * @param string $keywords
244
   *   One or more keywords to use for matching which contexts are allowed.
245
   * @param array $restrictions
246
   *   Array of context restrictions.
247
   * @param bool $skip_name_check
248
   *   If True, skip the check in select() for contexts whose names may have
249
   *   changed.
250
   */
251
  public function __construct($title) {
252
    // If it was possible, using variadic syntax this should be:
253
    // __construct($title, string ...$keywords, array $restrictions = NULL, bool $skip = NULL)
254
    // but that form isn't allowed.
255
    $args = func_get_args();
256
    $this->title = array_shift($args);
257

    
258
    // If we have a boolean value at the end for $skip_name_check, store it.
259
    if (is_bool(end($args))) {
260
      $this->skip_name_check = array_pop($args);
261
    }
262

    
263
    // If we were given restrictions at the end, store them.
264
    if (count($args) > 1 && is_array(end($args))) {
265
      $this->restrictions = array_pop($args);
266
    }
267

    
268
    if (count($args) === 1) {
269
      $args = array_shift($args);
270
    }
271
    $this->keywords = $args;
272
  }
273

    
274
  /**
275
   * Filter the contexts to determine which apply in the current environment.
276
   *
277
   * A context passes the filter if:
278
   *  - the context matches 'type' of the required keywords (uses
279
   *    ctools_context::is_type(), so includes 'any' matches, etc).
280
   *  - AND if restrictions are present, there are some common elements between
281
   *    the requirement and the context.
282
   *
283
   * @param array $contexts
284
   *   An array of ctools_context objects (or something which will cast to an
285
   *   array of them). The contexts to apply the filter on.
286
   *
287
   * @return array
288
   *   An array of context objects, keyed with the same keys used for $contexts,
289
   *   which pass the filter.
290
   *
291
   * @see ctools_context::is_type()
292
   */
293
  public function filter($contexts) {
294
    $result = array();
295

    
296
    /**
297
     * See which of these contexts are valid.
298
     * @var ctools_context $context
299
     */
300
    foreach ((array) $contexts as $cid => $context) {
301
      if ($context->is_type($this->keywords)) {
302

    
303
        // Compare to see if our contexts were met.
304
        if (!empty($this->restrictions) && !empty($context->restrictions)) {
305

    
306
          foreach ($this->restrictions as $key => $values) {
307
            // If we have a restriction, the context must either not have that
308
            // restriction listed, which means we simply don't know what it is,
309
            // or there must be an intersection of the restricted values on
310
            // both sides.
311
            if (!is_array($values)) {
312
              $values = array($values);
313
            }
314

    
315
            if (!empty($context->restrictions[$key])
316
              && !array_intersect($values, $context->restrictions[$key])
317
            ) {
318
              // Break out to check next context; this one fails the filter.
319
              continue 2;
320
            }
321
          }
322
        }
323
        // This context passes the filter.
324
        $result[$cid] = $context;
325
      }
326
    }
327

    
328
    return $result;
329
  }
330

    
331
  /**
332
   * Select one context from the list of contexts, accounting for changed IDs.
333
   *
334
   * Fundamentally, this returns $contexts[$context] or FALSE if that does not
335
   * exist. Additional logic accounts for changes in context names and dealing
336
   * with a $contexts parameter that is not an array.
337
   *
338
   * If we had requested a $context but that $context doesn't exist in our
339
   * context list, there is a good chance that what happened is the context
340
   * IDs changed. Look for another context that satisfies our requirements,
341
   * unless $skip_name_check is set.
342
   *
343
   * @param ctools_context|array $contexts
344
   *   A context, or an array of ctools_context.
345
   * @param string $context
346
   *   A context ID.
347
   *
348
   * @return bool|ctools_context
349
   *   The matching ctools_context, or False if no such context was found.
350
   */
351
  public function select($contexts, $context) {
352
    // Easier to deal with a standalone object as a 1-element array of objects.
353
    if (!is_array($contexts)) {
354
      if (is_object($contexts) && $contexts instanceof ctools_context) {
355
        $contexts = array($contexts->id => $contexts);
356
      }
357
      else {
358
        $contexts = array($contexts);
359
      }
360
    }
361

    
362
    // If we had requested a $context but that $context doesn't exist in our
363
    // context list, there is a good chance that what happened is the context
364
    // IDs changed. Check for another context that satisfies our requirements.
365
    if (!$this->skip_name_check
366
      && !empty($context) && !isset($contexts[$context])
367
    ) {
368
      $choices = $this->filter($contexts);
369

    
370
      // If we got a hit, take the first one that matches.
371
      if ($choices) {
372
        $keys = array_keys($choices);
373
        $context = reset($keys);
374
      }
375
    }
376

    
377
    if (empty($context) || empty($contexts[$context])) {
378
      return FALSE;
379
    }
380
    return $contexts[$context];
381
  }
382

    
383
}
384

    
385
/**
386
 * Used to compare to see if a list of contexts match an optional context. This
387
 * can produce empty contexts to use as placeholders.
388
 */
389
class ctools_context_optional extends ctools_context_required {
390

    
391
  /**
392
   * {@inheritdoc}
393
   */
394
  public $required = FALSE;
395

    
396
  /**
397
   * Add the 'empty' context to the existing set.
398
   *
399
   * @param array &$contexts
400
   *   An array of ctools_context objects.
401
   */
402
  public function add_empty(&$contexts) {
403
    $context = new ctools_context('any');
404
    $context->title = t('No context');
405
    $context->identifier = t('No context');
406
    $contexts['empty'] = $context;
407
  }
408

    
409
  /**
410
   * Filter the contexts to determine which apply in the current environment.
411
   *
412
   * As for ctools_context_required, but we add the empty context to those
413
   * passed in so the check is optional (i.e. if nothing else matches, the
414
   * empty context will, and so there will always be at least one matched).
415
   *
416
   * @param array $contexts
417
   *   An array of ctools_context objects (or something which will cast to an
418
   *   array of them). The contexts to apply the filter on.
419
   *
420
   * @return array
421
   *   An array of context objects, keyed with the same keys used for $contexts,
422
   *   which pass the filter.
423
   *
424
   * @see ctools_context::is_type()
425
   */
426
  public function filter($contexts) {
427
    /**
428
     * @todo We are assuming here that $contexts is actually an array, whereas
429
     * ctools_context_required::filter only requires $contexts is convertible
430
     * to an array.
431
     */
432
    $this->add_empty($contexts);
433
    return parent::filter($contexts);
434
  }
435

    
436
  /**
437
   * Select and return one context from the list of applicable contexts.
438
   *
439
   * Fundamentally, this returns $contexts[$context] or the empty context if
440
   * that does not exist.
441
   *
442
   * @param array $contexts
443
   *   The applicable contexts to check.
444
   * @param string $context
445
   *   The context id to check for.
446
   *
447
   * @return bool|ctools_context
448
   *   The matching ctools_context, or False if no such context was found.
449
   *
450
   * @see ctools_context_required::select()
451
   */
452
  public function select($contexts, $context) {
453
    /**
454
     * @todo We are assuming here that $contexts is actually an array, whereas
455
     * ctools_context_required::select permits ctools_context objects as well.
456
     */
457
    $this->add_empty($contexts);
458
    if (empty($context)) {
459
      return $contexts['empty'];
460
    }
461

    
462
    $result = parent::select($contexts, $context);
463

    
464
    // Don't flip out if it can't find the context; this is optional, put
465
    // in an empty.
466
    if ($result === FALSE) {
467
      $result = $contexts['empty'];
468
    }
469
    return $result;
470
  }
471

    
472
}
473

    
474
/**
475
 * Return a keyed array of context that match the given 'required context'
476
 * filters.
477
 *
478
 * Functions or systems that require contexts of a particular type provide a
479
 * ctools_context_required or ctools_context_optional object. This function
480
 * examines that object and an array of contexts to determine which contexts
481
 * match the filter.
482
 *
483
 * Since multiple contexts can be required, this function will accept either
484
 * an array of all required contexts, or just a single required context object.
485
 *
486
 * @param array $contexts
487
 *   A keyed array of all available contexts.
488
 * @param array|ctools_context_required|ctools_context_optional $required
489
 *   A *_required or *_optional object, or an array of such objects, which
490
 *   define the selection condition.
491
 *
492
 * @return array
493
 *   A keyed array of contexts that match the filter.
494
 */
495
function ctools_context_filter($contexts, $required) {
496
  if (is_array($required)) {
497
    $result = array();
498
    foreach ($required as $item) {
499
      $result = array_merge($result, _ctools_context_filter($contexts, $item));
500
    }
501
    return $result;
502
  }
503

    
504
  return _ctools_context_filter($contexts, $required);
505
}
506

    
507
/**
508
 * Helper function for ctools_context_filter().
509
 *
510
 * Used to transform the required context during the merge into the final array.
511
 *
512
 * @internal This function DOES NOT form part of the CTools API.
513
 *
514
 * @param array $contexts
515
 *   A keyed array of all available contexts.
516
 * @param ctools_context_required|ctools_context_optional $required
517
 *   A ctools_context_required or ctools_context_optional object, although if
518
 *   given something else will return an empty array.
519
 *
520
 * @return array
521
 */
522
function _ctools_context_filter($contexts, $required) {
523
  $result = array();
524

    
525
  if (is_object($required)) {
526
    $result = $required->filter($contexts);
527
  }
528

    
529
  return $result;
530
}
531

    
532
/**
533
 * Create a select box to choose possible contexts.
534
 *
535
 * This only creates a selector if there is actually a choice; if there
536
 * is only one possible context, that one is silently assigned.
537
 *
538
 * If an array of required contexts is provided, one selector will be
539
 * provided for each context.
540
 *
541
 * @param array $contexts
542
 *   A keyed array of all available contexts.
543
 * @param array|ctools_context_required|ctools_context_optional $required
544
 *   The required context object or array of objects.
545
 * @param array|string $default
546
 *   The default value for the select object, suitable for a #default_value
547
 *   render key. Where $required is an array, this is an array keyed by the
548
 *   same key values as $required for all keys where an empty string is not a
549
 *   suitable default. Otherwise it is just the default value.
550
 *
551
 * @return array
552
 *   A form element, or NULL if there are no contexts that satisfy the
553
 *   requirements.
554
 */
555
function ctools_context_selector($contexts, $required, $default) {
556
  if (is_array($required)) {
557
    $result = array('#tree' => TRUE);
558
    $count = 1;
559
    foreach ($required as $id => $item) {
560
      $result[] = _ctools_context_selector(
561
        $contexts, $item, isset($default[$id]) ? $default[$id] : '', $count++
562
      );
563
    }
564
    return $result;
565
  }
566

    
567
  return _ctools_context_selector($contexts, $required, $default);
568
}
569

    
570
/**
571
 * Helper function for ctools_context_selector().
572
 *
573
 * @internal This function DOES NOT form part of the CTools API. Use the API
574
 * function ctools_context_selector() instead.
575
 *
576
 * @param array $contexts
577
 *   A keyed array of all available contexts.
578
 * @param ctools_context_required|ctools_context_optional $required
579
 *   The required context object.
580
 * @param $default
581
 *   The default value for the select object, suitable for a #default_value
582
 *   render key.
583
 * @param int $num
584
 *   If supplied and non-zero, the title of the select form element will be
585
 *   "Context $num", otherwise it will be "Context".
586
 *
587
 * @return array
588
 *   A form element, or NULL if there are no contexts that satisfy the
589
 *   requirements.
590
 */
591
function _ctools_context_selector($contexts, $required, $default, $num = 0) {
592
  $filtered = ctools_context_filter($contexts, $required);
593
  $count = count($filtered);
594

    
595
  $form = array();
596

    
597
  if ($count >= 1) {
598
    // If there's more than one to choose from, create a select widget.
599
    foreach ($filtered as $cid => $context) {
600
      $options[$cid] = $context->get_identifier();
601
    }
602
    if (!empty($required->title)) {
603
      $title = $required->title;
604
    }
605
    else {
606
      $title = $num ? t('Context %count', array('%count' => $num)) : t('Context');
607
    }
608

    
609
    $form = array(
610
      '#type' => 'select',
611
      '#options' => $options,
612
      '#title' => $title,
613
      '#default_value' => $default,
614
    );
615
  }
616

    
617
  return $form;
618
}
619

    
620
/**
621
 * Are there enough contexts for a plugin?
622
 *
623
 * Some plugins can have a 'required contexts' item which can either
624
 * be a context requirement object or an array of them. When contexts
625
 * are required, items that do not have enough contexts should not
626
 * appear. This tests an item to see if it has enough contexts
627
 * to actually appear.
628
 *
629
 * @param $contexts
630
 *   A keyed array of all available contexts.
631
 * @param $required
632
 *   The required context object or array of objects.
633
 *
634
 * @return bool
635
 *   True if there are enough contexts, otherwise False.
636
 */
637
function ctools_context_match_requirements($contexts, $required) {
638
  if (!is_array($required)) {
639
    $required = array($required);
640
  }
641

    
642
  // Get the keys to avoid bugs in PHP 5.0.8 with keys and loops.
643
  // And use it to remove optional contexts.
644
  $keys = array_keys($required);
645
  foreach ($keys as $key) {
646
    if (empty($required[$key]->required)) {
647
      unset($required[$key]);
648
    }
649
  }
650

    
651
  $count = count($required);
652
  return (count(ctools_context_filter($contexts, $required)) >= $count);
653
}
654

    
655
/**
656
 * Create a select box to choose possible contexts.
657
 *
658
 * This only creates a selector if there is actually a choice; if there
659
 * is only one possible context, that one is silently assigned.
660
 *
661
 * If an array of required contexts is provided, one selector will be
662
 * provided for each context.
663
 *
664
 * @param $contexts
665
 *   A keyed array of all available contexts.
666
 * @param $required
667
 *   The required context object or array of objects.
668
 * @param array|string $default
669
 *   The default value for the select object, suitable for a #default_value
670
 *   render key. Where $required is an array, this is an array keyed by the
671
 *   same key values as $required for all keys where an empty string is not a
672
 *   suitable default. Otherwise it is just the default value.
673
 *
674
 * @return array
675
 *   A form element, or NULL if there are no contexts that satisfy the
676
 *   requirements.
677
 */
678
function ctools_context_converter_selector($contexts, $required, $default) {
679
  if (is_array($required)) {
680
    $result = array('#tree' => TRUE);
681
    $count = 1;
682
    foreach ($required as $id => $dependency) {
683
      $default_id = isset($default[$id]) ? $default[$id] : '';
684
      $result[] = _ctools_context_converter_selector(
685
        $contexts, $dependency, $default_id, $count++
686
      );
687
    }
688
    return $result;
689
  }
690

    
691
  return _ctools_context_converter_selector($contexts, $required, $default);
692
}
693

    
694
/**
695
 * Helper function for ctools_context_converter_selector().
696
 *
697
 * @internal This function DOES NOT form part of the CTools API. Use the API
698
 * function ctools_context_converter_selector() instead.
699
 *
700
 * @param array $contexts
701
 *   A keyed array of all available contexts.
702
 * @param ctools_context $required
703
 *   The required context object.
704
 * @param $default
705
 *   The default value for the select object, suitable for a #default_value
706
 *   render key.
707
 * @param int $num
708
 *   If supplied and non-zero, the title of the select form element will be
709
 *   "Context $num", otherwise it will be "Context".
710
 *
711
 * @return array|null
712
 *   A form element, or NULL if there are no contexts that satisfy the
713
 *   requirements.
714
 */
715
function _ctools_context_converter_selector($contexts, $required, $default, $num = 0) {
716
  $filtered = ctools_context_filter($contexts, $required);
717
  $count = count($filtered);
718

    
719
  if ($count > 1) {
720
    // If there's more than one to choose from, create a select widget.
721
    $options = array();
722
    foreach ($filtered as $cid => $context) {
723
      if ($context->type === 'any') {
724
        $options[''] = t('No context');
725
        continue;
726
      }
727
      $key = $context->get_identifier();
728
      if ($converters = ctools_context_get_converters($cid . '.', $context)) {
729
        $options[$key] = $converters;
730
      }
731
    }
732
    if (empty($options)) {
733
      return array(
734
        '#type' => 'value',
735
        '#value' => 'any',
736
      );
737
    }
738
    if (!empty($required->title)) {
739
      $title = $required->title;
740
    }
741
    else {
742
      $title = $num ? t('Context %count', array('%count' => $num)) : t('Context');
743
    }
744

    
745
    return array(
746
      '#type' => 'select',
747
      '#options' => $options,
748
      '#title' => $title,
749
      '#description' => t('Please choose which context and how you would like it converted.'),
750
      '#default_value' => $default,
751
    );
752
  }
753
  else {
754
    // Not enough choices to need a selector, so don't make one.
755
    return NULL;
756
  }
757
}
758

    
759
/**
760
 * Get a list of converters available for a given context.
761
 *
762
 * @param string $cid
763
 *   A context ID.
764
 * @param ctools_context $context
765
 *   The context for which converters are needed.
766
 *
767
 * @return array
768
 *   A list of context converters.
769
 */
770
function ctools_context_get_converters($cid, $context) {
771
  if (empty($context->plugin)) {
772
    return array();
773
  }
774

    
775
  return _ctools_context_get_converters($cid, $context->plugin);
776
}
777

    
778
/**
779
 * Get a list of converters available for a given context.
780
 *
781
 * @internal This function DOES NOT form part of the CTools API. Use the API
782
 * function ctools_context_get_converters() instead.
783
 *
784
 * @param string $id
785
 *   A context ID.
786
 * @param string $plugin_name
787
 *   The name of the context plugin.
788
 *
789
 * @return array
790
 *   A list of context converters.
791
 */
792
function _ctools_context_get_converters($id, $plugin_name) {
793
  $plugin = ctools_get_context($plugin_name);
794
  if (empty($plugin['convert list'])) {
795
    return array();
796
  }
797

    
798
  $converters = array();
799
  if (is_array($plugin['convert list'])) {
800
    $converters = $plugin['convert list'];
801
  }
802
  elseif ($function = ctools_plugin_get_function($plugin, 'convert list')) {
803
    $converters = (array) $function($plugin);
804
  }
805

    
806
  foreach (module_implements('ctools_context_convert_list_alter') as $module) {
807
    $function = $module . '_ctools_context_convert_list_alter';
808
    $function($plugin, $converters);
809
  }
810

    
811
  // Now, change them all to include the plugin:
812
  $return = array();
813
  foreach ($converters as $key => $title) {
814
    $return[$id . $key] = $title;
815
  }
816

    
817
  natcasesort($return);
818
  return $return;
819
}
820

    
821
/**
822
 * Get a list of all contexts converters available.
823
 *
824
 * For all contexts returned by ctools_get_contexts(), return the converter
825
 * for all contexts that have one.
826
 *
827
 * @return array
828
 *   A list of context converters, keyed by the title of the converter.
829
 */
830
function ctools_context_get_all_converters() {
831
  $contexts = ctools_get_contexts();
832
  $converters = array();
833
  foreach ($contexts as $name => $context) {
834
    if (empty($context['no required context ui'])) {
835
      $context_converters = _ctools_context_get_converters($name . '.', $name);
836
      if ($context_converters) {
837
        $converters[$context['title']] = $context_converters;
838
      }
839
    }
840
  }
841

    
842
  return $converters;
843
}
844

    
845
/**
846
 * Let the context convert an argument based upon the converter that was given.
847
 *
848
 * @param ctools_context $context
849
 *   The context object.
850
 * @param string $converter
851
 *   The type of converter to use, which should be a string provided by the
852
 *   converter list function.
853
 * @param array $converter_options
854
 *   An array of options to pass on to the generation function. For contexts
855
 *   that use token module, of particular use is 'sanitize' => FALSE which can
856
 *   get raw tokens. This should ONLY be used in values that will later be
857
 *   treated as unsafe user input since these values are by themselves unsafe.
858
 *   It is particularly useful to get raw values from Field API.
859
 *
860
 * @return string|null
861
 */
862
function ctools_context_convert_context($context, $converter, $converter_options = array()) {
863
  // Contexts without plugins might be optional placeholders.
864
  if (empty($context->plugin)) {
865
    return NULL;
866
  }
867

    
868
  $value = $context->argument;
869
  $plugin = ctools_get_context($context->plugin);
870
  if ($function = ctools_plugin_get_function($plugin, 'convert')) {
871
    $value = $function($context, $converter, $converter_options);
872
  }
873

    
874
  foreach (module_implements('ctools_context_converter_alter') as $module) {
875
    $function = $module . '_ctools_context_converter_alter';
876
    $function($context, $converter, $value, $converter_options);
877
  }
878

    
879
  return $value;
880
}
881

    
882
/**
883
 * Choose a context or contexts based upon the selection made via
884
 * ctools_context_filter.
885
 *
886
 * @param array $contexts
887
 *   A keyed array of all available contexts.
888
 * @param array|ctools_context_required $required
889
 *   The required context object(s) provided by the plugin.
890
 * @param $context
891
 *   The selection made using ctools_context_selector().
892
 *
893
 * @return ctools_context|array|false
894
 *   Returns FALSE if $required is not an object, or array of objects, or
895
 *   the value of $required->select() for the context, or an array of those (if
896
 *   passed an array in $required).
897
 */
898
function ctools_context_select($contexts, $required, $context) {
899
  if (is_array($required)) {
900

    
901
    /**
902
     * @var array $required
903
     *   Array of required context objects.
904
     * @var ctools_context_required $item
905
     *   A required context object.
906
     */
907
    $result = array();
908
    foreach ($required as $id => $item) {
909
      // @todo What's the difference between the following and "empty($item)" ?
910
      if (empty($required[$id])) {
911
        continue;
912
      }
913

    
914
      if (($result[] = _ctools_context_select($contexts, $item, $context[$id])) === FALSE) {
915
        return FALSE;
916
      }
917
    }
918
    return $result;
919
  }
920

    
921
  return _ctools_context_select($contexts, $required, $context);
922
}
923

    
924
/**
925
 * Helper function for calling the required context object's selection function.
926
 *
927
 * This function DOES NOT form part of the CTools API.
928
 *
929
 * @param array $contexts
930
 *   A keyed array of all available contexts.
931
 * @param ctools_context_required $required
932
 *   The required context object provided by the plugin.
933
 * @param $context
934
 *   The selection made using ctools_context_selector().
935
 *
936
 * @return ctools_context|bool
937
 *   FALSE if the $required is not an object. A ctools_context object if one
938
 *   matched.
939
 */
940
function _ctools_context_select($contexts, $required, $context) {
941
  if (!is_object($required)) {
942
    return FALSE;
943
  }
944

    
945
  return $required->select($contexts, $context);
946
}
947

    
948
/**
949
 * Create a new context object.
950
 *
951
 * @param string $type
952
 *   The type of context to create; this loads a plugin.
953
 * @param mixed $data
954
 *   The data to put into the context.
955
 * @param $conf
956
 *   A configuration structure if this context was created via UI.
957
 *
958
 * @return ctools_context
959
 *   A $context or NULL if one could not be created.
960
 */
961
function ctools_context_create($type, $data = NULL, $conf = FALSE) {
962
  ctools_include('plugins');
963
  $plugin = ctools_get_context($type);
964

    
965
  if ($function = ctools_plugin_get_function($plugin, 'context')) {
966
    return $function(FALSE, $data, $conf, $plugin);
967
  }
968
}
969

    
970
/**
971
 * Create an empty context object.
972
 *
973
 * Empty context objects are primarily used as placeholders in the UI where
974
 * the actual contents of a context object may not be known. It may have
975
 * additional text embedded to give the user clues as to how the context
976
 * is used.
977
 *
978
 * @param $type
979
 *   The type of context to create; this loads a plugin.
980
 *
981
 * @return ctools_context
982
 *   A $context or NULL if one could not be created.
983
 */
984
function ctools_context_create_empty($type) {
985
  $plugin = ctools_get_context($type);
986
  if ($function = ctools_plugin_get_function($plugin, 'context')) {
987
    $context = $function(TRUE, NULL, FALSE, $plugin);
988
    if (is_object($context)) {
989
      $context->empty = TRUE;
990
    }
991

    
992
    return $context;
993
  }
994
}
995

    
996
/**
997
 * Perform keyword and context substitutions.
998
 *
999
 * @param string $string
1000
 *   The string in which to replace keywords.
1001
 * @param array $keywords
1002
 *   Array of keyword-replacement pairs.
1003
 * @param array $contexts
1004
 *
1005
 * @param array $converter_options
1006
 *   Options to pass on to ctools_context_convert_context(), defaults to an
1007
 *   empty array.
1008
 *
1009
 * @return string
1010
 *   The returned string, with substitutions performed.
1011
 */
1012
function ctools_context_keyword_substitute($string, $keywords, $contexts, array $converter_options = array()) {
1013
  // Ensure a default keyword exists:
1014
  $keywords['%%'] = '%';
1015

    
1016
  // Match contexts to the base keywords:
1017
  $context_keywords = array();
1018
  foreach ($contexts as $context) {
1019
    if (isset($context->keyword)) {
1020
      $context_keywords[$context->keyword] = $context;
1021
    }
1022
  }
1023

    
1024
  // Look for context matches we we only have to convert known matches.
1025
  $matches = array();
1026
  if (preg_match_all('/%(%|[a-zA-Z0-9_-]+(?:\:[a-zA-Z0-9_-]+)*)/us', $string, $matches)) {
1027
    foreach ($matches[1] as $keyword) {
1028
      // Ignore anything it finds with %%.
1029
      if ($keyword[0] == '%') {
1030
        continue;
1031
      }
1032

    
1033
      // If the keyword is already set by something passed in, don't try to
1034
      // overwrite it.
1035
      if (array_key_exists('%' . $keyword, $keywords)) {
1036
        continue;
1037
      }
1038

    
1039
      // Figure out our keyword and converter, if specified.
1040
      if (strpos($keyword, ':')) {
1041
        list($context, $converter) = explode(':', $keyword, 2);
1042
      }
1043
      else {
1044
        $context = $keyword;
1045
        if (isset($context_keywords[$keyword])) {
1046
          $plugin = ctools_get_context($context_keywords[$context]->plugin);
1047

    
1048
          // Fall back to a default converter, if specified.
1049
          if ($plugin && !empty($plugin['convert default'])) {
1050
            $converter = $plugin['convert default'];
1051
          }
1052
        }
1053
      }
1054

    
1055
      if (!isset($context_keywords[$context])) {
1056
        $keywords['%' . $keyword] = '%' . $keyword;
1057
      }
1058
      else {
1059
        if (empty($context_keywords[$context]) || !empty($context_keywords[$context]->empty)) {
1060
          $keywords['%' . $keyword] = '';
1061
        }
1062
        else {
1063
          if (!empty($converter)) {
1064
            $keywords['%' . $keyword] = ctools_context_convert_context($context_keywords[$context], $converter, $converter_options);
1065
          }
1066
          else {
1067
            $keywords['%' . $keyword] = $context_keywords[$keyword]->title;
1068
          }
1069
        }
1070
      }
1071
    }
1072
  }
1073
  return strtr($string, $keywords);
1074
}
1075

    
1076
/**
1077
 * Determine a unique context ID for a context.
1078
 *
1079
 * Often contexts of many different types will be placed into a list. This
1080
 * ensures that even though contexts of multiple types may share IDs, they
1081
 * are unique in the final list.
1082
 */
1083
function ctools_context_id($context, $type = 'context') {
1084
  // If not set, FALSE or empty.
1085
  if (!isset($context['id']) || !$context['id']) {
1086
    $context['id'] = 1;
1087
  }
1088

    
1089
  // @todo is '' the appropriate default value?
1090
  $name = isset($context['name']) ? $context['name'] : '';
1091

    
1092
  return $type . '_' . $name . '_' . $context['id'];
1093
}
1094

    
1095
/**
1096
 * Get the next id available given a list of already existing objects.
1097
 *
1098
 * This finds the next id available for the named object.
1099
 *
1100
 * @param array $objects
1101
 *   A list of context descriptor objects, i.e, arguments, relationships,
1102
 *   contexts, etc.
1103
 * @param string $name
1104
 *   The name being used.
1105
 *
1106
 * @return int
1107
 *   The next integer id available.
1108
 */
1109
function ctools_context_next_id($objects, $name) {
1110
  $id = 0;
1111
  // Figure out which instance of this argument we're creating.
1112
  if (!$objects) {
1113
    return $id + 1;
1114
  }
1115

    
1116
  foreach ($objects as $object) {
1117
    if (isset($object['name']) && $object['name'] === $name) {
1118
      if (isset($object['id']) && $object['id'] > $id) {
1119
        $id = $object['id'];
1120
      }
1121
      // @todo If obj has no 'id', should we increment local id? $id = $id + 1;
1122
    }
1123
  }
1124

    
1125
  return $id + 1;
1126
}
1127

    
1128
// ---------------------------------------------------------------------------
1129
// Functions related to contexts from arguments.
1130
/**
1131
 * Fetch metadata for a specific argument plugin.
1132
 *
1133
 * @param $argument
1134
 *   Name of an argument plugin.
1135
 *
1136
 * @return array
1137
 *   An array with information about the requested argument plugin.
1138
 */
1139

    
1140
function ctools_get_argument($argument) {
1141
  ctools_include('plugins');
1142
  return ctools_get_plugins('ctools', 'arguments', $argument);
1143
}
1144

    
1145
/**
1146
 * Fetch metadata for all argument plugins.
1147
 *
1148
 * @return array
1149
 *   An array of arrays with information about all available argument plugins.
1150
 */
1151
function ctools_get_arguments() {
1152
  ctools_include('plugins');
1153
  return ctools_get_plugins('ctools', 'arguments');
1154
}
1155

    
1156
/**
1157
 * Get a context from an argument.
1158
 *
1159
 * @param $argument
1160
 *   The configuration of an argument. It must contain the following data:
1161
 *   - name: The name of the argument plugin being used.
1162
 *   - argument_settings: The configuration based upon the plugin forms.
1163
 *   - identifier: The human readable identifier for this argument, usually
1164
 *     defined by the UI.
1165
 *   - keyword: The keyword used for this argument for substitutions.
1166
 *
1167
 * @param $arg
1168
 *   The actual argument received. This is expected to be a string from a URL
1169
 *   but this does not have to be the only source of arguments.
1170
 * @param $empty
1171
 *   If true, the $arg will not be used to load the context. Instead, an empty
1172
 *   placeholder context will be loaded.
1173
 *
1174
 * @return ctools_context
1175
 *   A context object if one can be loaded.
1176
 */
1177
function ctools_context_get_context_from_argument($argument, $arg, $empty = FALSE) {
1178
  ctools_include('plugins');
1179
  if (empty($argument['name'])) {
1180
    return NULL;
1181
  }
1182

    
1183
  $function = ctools_plugin_load_function('ctools', 'arguments', $argument['name'], 'context');
1184
  if ($function) {
1185
    // Backward compatibility: Merge old style settings into new style:
1186
    if (!empty($argument['settings'])) {
1187
      $argument += $argument['settings'];
1188
      unset($argument['settings']);
1189
    }
1190

    
1191
    $context = $function($arg, $argument, $empty);
1192

    
1193
    if (is_object($context)) {
1194
      $context->identifier = $argument['identifier'];
1195
      $context->page_title = isset($argument['title']) ? $argument['title'] : '';
1196
      $context->keyword = $argument['keyword'];
1197
      $context->id = ctools_context_id($argument, 'argument');
1198
      $context->original_argument = $arg;
1199

    
1200
      if (!empty($context->empty)) {
1201
        $context->placeholder = array(
1202
          'type' => 'argument',
1203
          'conf' => $argument,
1204
        );
1205
      }
1206
    }
1207
    return $context;
1208
  }
1209
}
1210

    
1211
/**
1212
 * Retrieve a list of empty contexts for all arguments.
1213
 *
1214
 * @param array $arguments
1215
 *
1216
 * @return array
1217
 *
1218
 * @see ctools_context_get_context_from_arguments()
1219
 */
1220
function ctools_context_get_placeholders_from_argument($arguments) {
1221
  $contexts = array();
1222
  foreach ($arguments as $argument) {
1223
    $context = ctools_context_get_context_from_argument($argument, NULL, TRUE);
1224
    if ($context) {
1225
      $contexts[ctools_context_id($argument, 'argument')] = $context;
1226
    }
1227
  }
1228
  return $contexts;
1229
}
1230

    
1231
/**
1232
 * Load the contexts for a given list of arguments.
1233
 *
1234
 * @param array $arguments
1235
 *   The array of argument definitions.
1236
 * @param array &$contexts
1237
 *   The array of existing contexts. New contexts will be added to this array.
1238
 * @param array $args
1239
 *   The arguments to load.
1240
 *
1241
 * @return bool
1242
 *   TRUE if all is well, FALSE if an argument wants to 404.
1243
 *
1244
 * @see ctools_context_get_context_from_argument()
1245
 */
1246
function ctools_context_get_context_from_arguments($arguments, &$contexts, $args) {
1247
  foreach ($arguments as $argument) {
1248
    // Pull the argument off the list.
1249
    $arg = array_shift($args);
1250
    $id = ctools_context_id($argument, 'argument');
1251

    
1252
    // For % arguments embedded in the URL, our context is already loaded.
1253
    // There is no need to go and load it again.
1254
    if (empty($contexts[$id])) {
1255
      if ($context = ctools_context_get_context_from_argument($argument, $arg)) {
1256
        $contexts[$id] = $context;
1257
      }
1258
    }
1259
    else {
1260
      $context = $contexts[$id];
1261
    }
1262

    
1263
    if ((empty($context) || empty($context->data))
1264
      && !empty($argument['default'])
1265
      && $argument['default'] === '404'
1266
    ) {
1267
      return FALSE;
1268
    }
1269
  }
1270
  return TRUE;
1271
}
1272

    
1273
// ---------------------------------------------------------------------------
1274
// Functions related to contexts from relationships.
1275
/**
1276
 * Fetch plugin metadata for a specific relationship plugin.
1277
 *
1278
 * @param $relationship
1279
 *   Name of a panel content type.
1280
 *
1281
 * @return array
1282
 *   An array with information about the requested relationship.
1283
 *
1284
 * @see ctools_get_relationships()
1285
 */
1286

    
1287
function ctools_get_relationship($relationship) {
1288
  ctools_include('plugins');
1289
  return ctools_get_plugins('ctools', 'relationships', $relationship);
1290
}
1291

    
1292
/**
1293
 * Fetch metadata for all relationship plugins.
1294
 *
1295
 * @return array
1296
 *   An array of arrays with information about all available relationships.
1297
 *
1298
 * @see ctools_get_relationship()
1299
 */
1300
function ctools_get_relationships() {
1301
  ctools_include('plugins');
1302
  return ctools_get_plugins('ctools', 'relationships');
1303
}
1304

    
1305
/**
1306
 * Return a context from a relationship.
1307
 *
1308
 * @param array $relationship
1309
 *   The configuration of a relationship. It must contain the following data:
1310
 *   - name: The name of the relationship plugin being used.
1311
 *   - relationship_settings: The configuration based upon the plugin forms.
1312
 *   - identifier: The human readable identifier for this relationship, usually
1313
 *     defined by the UI.
1314
 *   - keyword: The keyword used for this relationship for substitutions.
1315
 *
1316
 * @param ctools_context $source_context
1317
 *   The context this relationship is based upon.
1318
 * @param bool $placeholders
1319
 *   If TRUE, placeholders are acceptable.
1320
 *
1321
 * @return ctools_context|null
1322
 *   A context object if one can be loaded, otherwise NULL.
1323
 *
1324
 * @see ctools_context_get_relevant_relationships()
1325
 * @see ctools_context_get_context_from_relationships()
1326
 */
1327
function ctools_context_get_context_from_relationship($relationship, $source_context, $placeholders = FALSE) {
1328
  ctools_include('plugins');
1329
  $function = ctools_plugin_load_function('ctools', 'relationships', $relationship['name'], 'context');
1330
  if ($function) {
1331
    // Backward compatibility: Merge old style settings into new style:
1332
    if (!empty($relationship['relationship_settings'])) {
1333
      $relationship += $relationship['relationship_settings'];
1334
      unset($relationship['relationship_settings']);
1335
    }
1336

    
1337
    $context = $function($source_context, $relationship, $placeholders);
1338
    if ($context) {
1339
      $context->identifier = $relationship['identifier'];
1340
      $context->page_title = isset($relationship['title']) ? $relationship['title'] : '';
1341
      $context->keyword = $relationship['keyword'];
1342
      if (!empty($context->empty)) {
1343
        $context->placeholder = array(
1344
          'type' => 'relationship',
1345
          'conf' => $relationship,
1346
        );
1347
      }
1348
      return $context;
1349
    }
1350
  }
1351
  return NULL;
1352
}
1353

    
1354
/**
1355
 * Fetch all relevant relationships.
1356
 *
1357
 * Relevant relationships are any relationship that can be created based upon
1358
 * the list of existing contexts. For example, the 'node author' relationship
1359
 * is relevant if there is a 'node' context, but makes no sense if there is
1360
 * not one.
1361
 *
1362
 * @param $contexts
1363
 *   An array of contexts used to figure out which relationships are relevant.
1364
 *
1365
 * @return array
1366
 *   An array of relationship keys that are relevant for the given set of
1367
 *   contexts.
1368
 *
1369
 * @see ctools_context_filter()
1370
 * @see ctools_context_get_context_from_relationship()
1371
 * @see ctools_context_get_context_from_relationships()
1372
 */
1373
function ctools_context_get_relevant_relationships($contexts) {
1374
  $relevant = array();
1375
  $relationships = ctools_get_relationships();
1376

    
1377
  // Go through each relationship.
1378
  foreach ($relationships as $rid => $relationship) {
1379
    // For each relationship, see if there is a context that satisfies it.
1380
    if (empty($relationship['no ui'])
1381
      && ctools_context_filter($contexts, $relationship['required context'])
1382
    ) {
1383
      $relevant[$rid] = $relationship['title'];
1384
    }
1385
  }
1386

    
1387
  return $relevant;
1388
}
1389

    
1390
/**
1391
 * Fetch all active relationships.
1392
 *
1393
 * @param $relationships
1394
 *   An keyed array of relationship data including:
1395
 *   - name: name of relationship
1396
 *   - context: context id relationship belongs to. This will be used to
1397
 *     identify which context in the $contexts array to use to create the
1398
 *     relationship context.
1399
 *
1400
 * @param $contexts
1401
 *   A keyed array of contexts used to figure out which relationships
1402
 *   are relevant. New contexts will be added to this.
1403
 *
1404
 * @param $placeholders
1405
 *   If TRUE, placeholders are acceptable.
1406
 *
1407
 * @see ctools_context_get_context_from_relationship()
1408
 * @see ctools_context_get_relevant_relationships()
1409
 */
1410
function ctools_context_get_context_from_relationships($relationships, &$contexts, $placeholders = FALSE) {
1411
  foreach ($relationships as $rdata) {
1412
    if (!isset($rdata['context'])) {
1413
      continue;
1414
    }
1415

    
1416
    if (is_array($rdata['context'])) {
1417
      $rcontexts = array();
1418
      foreach ($rdata['context'] as $cid) {
1419
        if (!empty($contexts[$cid])) {
1420
          $rcontexts[] = $contexts[$cid];
1421
        }
1422
      }
1423
    }
1424
    elseif (!empty($contexts[$rdata['context']])) {
1425
      $rcontexts = $contexts[$rdata['context']];
1426
    }
1427

    
1428
    $cid = ctools_context_id($rdata, 'relationship');
1429
    if ($context = ctools_context_get_context_from_relationship($rdata, $rcontexts)) {
1430
      $contexts[$cid] = $context;
1431
    }
1432
  }
1433
}
1434

    
1435
// ---------------------------------------------------------------------------
1436
// Functions related to loading contexts from simple context definitions.
1437
/**
1438
 * Fetch metadata on a specific context plugin.
1439
 *
1440
 * @param string $context
1441
 *   Name of a context.
1442
 *
1443
 * @return array
1444
 *   An array with information about the requested panel context.
1445
 */
1446

    
1447
function ctools_get_context($context) {
1448
  static $gate = array();
1449
  ctools_include('plugins');
1450
  $plugin = ctools_get_plugins('ctools', 'contexts', $context);
1451
  if (empty($gate['context']) && !empty($plugin['superceded by'])) {
1452
    // This gate prevents infinite loops.
1453
    $gate[$context] = TRUE;
1454
    $new_plugin = ctools_get_plugins('ctools', 'contexts', $plugin['superceded by']);
1455
    $gate[$context] = FALSE;
1456

    
1457
    // If a new plugin was returned, return it. Otherwise fall through and
1458
    // return the original we fetched.
1459
    if ($new_plugin) {
1460
      return $new_plugin;
1461
    }
1462
  }
1463

    
1464
  return $plugin;
1465
}
1466

    
1467
/**
1468
 * Fetch metadata for all context plugins.
1469
 *
1470
 * @return array
1471
 *   An array of arrays with information about all available panel contexts.
1472
 */
1473
function ctools_get_contexts() {
1474
  ctools_include('plugins');
1475
  return ctools_get_plugins('ctools', 'contexts');
1476
}
1477

    
1478
/**
1479
 * Return a context object from a context definition array.
1480
 *
1481
 * The input $context contains the information needed to identify and invoke
1482
 * the context plugin and create the plugin context from that.
1483
 *
1484
 * @param array $context
1485
 *   The configuration of a context. It must contain the following data:
1486
 *   - name: The name of the context plugin being used.
1487
 *   - context_settings: The configuration based upon the plugin forms.
1488
 *   - identifier: The human readable identifier for this context, usually
1489
 *     defined by the UI.
1490
 *   - keyword: The keyword used for this context for substitutions.
1491
 * @param string $type
1492
 *   This is either 'context' which indicates the context will be loaded
1493
 *   from data in the settings, or 'requiredcontext' which means the
1494
 *   context must be acquired from an external source. This is the method
1495
 *   used to pass pure contexts from one system to another.
1496
 * @param mixed $argument
1497
 *   Optional information passed to the plugin context via the arg defined in
1498
 *   the plugin's "placeholder name" field.
1499
 *
1500
 * @return ctools_context|null
1501
 *   A context object if one can be loaded.
1502
 *
1503
 * @see ctools_get_context()
1504
 * @see ctools_plugin_get_function()
1505
 */
1506
function ctools_context_get_context_from_context($context, $type = 'context', $argument = NULL) {
1507
  ctools_include('plugins');
1508
  $plugin = ctools_get_context($context['name']);
1509
  $function = ctools_plugin_get_function($plugin, 'context');
1510
  if ($function) {
1511
    // Backward compatibility: Merge old style settings into new style:
1512
    if (!empty($context['context_settings'])) {
1513
      $context += $context['context_settings'];
1514
      unset($context['context_settings']);
1515
    }
1516

    
1517
    if (isset($argument) && isset($plugin['placeholder name'])) {
1518
      $context[$plugin['placeholder name']] = $argument;
1519
    }
1520

    
1521
    $return = $function($type == 'requiredcontext', $context, TRUE, $plugin);
1522
    if ($return) {
1523
      $return->identifier = $context['identifier'];
1524
      $return->page_title = isset($context['title']) ? $context['title'] : '';
1525
      $return->keyword = $context['keyword'];
1526

    
1527
      if (!empty($context->empty)) {
1528
        $context->placeholder = array(
1529
          'type' => 'context',
1530
          'conf' => $context,
1531
        );
1532
      }
1533

    
1534
      return $return;
1535
    }
1536
  }
1537

    
1538
  return NULL;
1539
}
1540

    
1541
/**
1542
 * Retrieve a list of base contexts based upon a simple 'contexts' definition.
1543
 *
1544
 * For required contexts this will always retrieve placeholders.
1545
 *
1546
 * @param $contexts
1547
 *   The list of contexts defined in the UI.
1548
 * @param $type
1549
 *   Either 'context' or 'requiredcontext', which indicates whether the contexts
1550
 *   are loaded from internal data or copied from an external source.
1551
 * @param $placeholders
1552
 *   If True, placeholders are acceptable.
1553
 *
1554
 * @return array
1555
 *   Array of contexts, keyed by context ID.
1556
 */
1557
function ctools_context_get_context_from_contexts($contexts, $type = 'context', $placeholders = FALSE) {
1558
  $return = array();
1559
  foreach ($contexts as $context) {
1560
    $ctext = ctools_context_get_context_from_context($context, $type);
1561
    if ($ctext) {
1562
      if ($placeholders) {
1563
        $ctext->placeholder = TRUE;
1564
      }
1565
      $return[ctools_context_id($context, $type)] = $ctext;
1566
    }
1567
  }
1568
  return $return;
1569
}
1570

    
1571
/**
1572
 * Match up external contexts to our required contexts.
1573
 *
1574
 * This function is used to create a list of contexts with proper IDs based
1575
 * upon a list of required contexts.
1576
 *
1577
 * These contexts passed in should match the numeric positions of the required
1578
 * contexts. The caller must ensure this has already happened correctly as this
1579
 * function will not detect errors here.
1580
 *
1581
 * @param $required
1582
 *   A list of required contexts as defined by the UI.
1583
 * @param $contexts
1584
 *   A list of matching contexts as passed in from the calling system.
1585
 *
1586
 * @return array
1587
 *   Array of contexts, keyed by context ID.
1588
 */
1589
function ctools_context_match_required_contexts($required, $contexts) {
1590
  $return = array();
1591
  if (!is_array($required)) {
1592
    return $return;
1593
  }
1594

    
1595
  foreach ($required as $r) {
1596
    $context = clone array_shift($contexts);
1597
    $context->identifier = $r['identifier'];
1598
    $context->page_title = isset($r['title']) ? $r['title'] : '';
1599
    $context->keyword = $r['keyword'];
1600
    $return[ctools_context_id($r, 'requiredcontext')] = $context;
1601
  }
1602

    
1603
  return $return;
1604
}
1605

    
1606
/**
1607
 * Load a full array of contexts for an object.
1608
 *
1609
 * Not all of the types need to be supported by this object.
1610
 *
1611
 * This function is not used to load contexts from external data, but may be
1612
 * used to load internal contexts and relationships. Otherwise it can also be
1613
 * used to generate a full set of placeholders for UI purposes.
1614
 *
1615
 * @param object $object
1616
 *   An object that contains some or all of the following variables:
1617
 *
1618
 *   - requiredcontexts: A list of UI configured contexts that are required
1619
 *     from an external source. Since these require external data, they will
1620
 *     only be added if $placeholders is set to TRUE, and empty contexts will
1621
 *     be created.
1622
 *   - arguments: A list of UI configured arguments that will create contexts.
1623
 *     As these require external data, they will only be added if $placeholders
1624
 *     is set to TRUE.
1625
 *   - contexts: A list of UI configured contexts that have no external source,
1626
 *     and are essentially hardcoded. For example, these might configure a
1627
 *     particular node or a particular taxonomy term.
1628
 *   - relationships: A list of UI configured contexts to be derived from other
1629
 *     contexts that already exist from other sources. For example, these might
1630
 *     be used to get a user object from a node via the node author
1631
 *     relationship.
1632
 * @param bool $placeholders
1633
 *   If True, this will generate placeholder objects for any types this function
1634
 *   cannot load.
1635
 * @param array $contexts
1636
 *   An array of pre-existing contexts that will be part of the return value.
1637
 *
1638
 * @return array
1639
 *   Merged output of all results of ctools_context_get_context_from_contexts().
1640
 */
1641
function ctools_context_load_contexts($object, $placeholders = TRUE, $contexts = array()) {
1642
  if (!empty($object->base_contexts)) {
1643
    $contexts += $object->base_contexts;
1644
  }
1645

    
1646
  if ($placeholders) {
1647
    // This will load empty contexts as placeholders for arguments that come
1648
    // from external sources. If this isn't set, it's assumed these context
1649
    // will already have been matched up and loaded.
1650
    if (!empty($object->requiredcontexts) && is_array($object->requiredcontexts)) {
1651
      $contexts += ctools_context_get_context_from_contexts($object->requiredcontexts, 'requiredcontext', $placeholders);
1652
    }
1653

    
1654
    if (!empty($object->arguments) && is_array($object->arguments)) {
1655
      $contexts += ctools_context_get_placeholders_from_argument($object->arguments);
1656
    }
1657
  }
1658

    
1659
  if (!empty($object->contexts) && is_array($object->contexts)) {
1660
    $contexts += ctools_context_get_context_from_contexts($object->contexts, 'context', $placeholders);
1661
  }
1662

    
1663
  // Add contexts from relationships.
1664
  if (!empty($object->relationships) && is_array($object->relationships)) {
1665
    ctools_context_get_context_from_relationships($object->relationships, $contexts, $placeholders);
1666
  }
1667

    
1668
  return $contexts;
1669
}
1670

    
1671
/**
1672
 * Return the first context with a form id from a list of contexts.
1673
 *
1674
 * This function is used to figure out which contexts represents 'the form'
1675
 * from a list of contexts. Only one contexts can actually be 'the form' for
1676
 * a given page, since the @code{<form>} tag can not be embedded within
1677
 * itself.
1678
 */
1679
function ctools_context_get_form($contexts) {
1680
  if (!empty($contexts)) {
1681
    foreach ($contexts as $id => $context) {
1682
      // If a form shows its id as being a 'required context' that means the
1683
      // the context is external to this display and does not count.
1684
      if (!empty($context->form_id) && substr($id, 0, 15) != 'requiredcontext') {
1685
        return $context;
1686
      }
1687
    }
1688
  }
1689
}
1690

    
1691
/**
1692
 * Replace placeholders with real contexts using data extracted from a form
1693
 * for the purposes of previews.
1694
 *
1695
 * @param $contexts
1696
 *   All of the contexts, including the placeholders.
1697
 * @param $arguments
1698
 *   The arguments. These will be acquired from $form_state['values'] and the
1699
 *   keys must match the context IDs.
1700
 *
1701
 * @return array
1702
 *   A new $contexts array containing the replaced contexts. Not all contexts
1703
 *   may be replaced if, for example, an argument was unable to be converted
1704
 *   into a context.
1705
 */
1706
function ctools_context_replace_placeholders($contexts, $arguments) {
1707
  foreach ($contexts as $cid => $context) {
1708
    if (empty($context->empty)) {
1709
      continue;
1710
    }
1711

    
1712
    $new_context = NULL;
1713
    switch ($context->placeholder['type']) {
1714
      case 'relationship':
1715
        $relationship = $context->placeholder['conf'];
1716
        if (isset($contexts[$relationship['context']])) {
1717
          $new_context = ctools_context_get_context_from_relationship($relationship, $contexts[$relationship['context']]);
1718
        }
1719
        break;
1720

    
1721
      case 'argument':
1722
        if (isset($arguments[$cid]) && $arguments[$cid] !== '') {
1723
          $argument = $context->placeholder['conf'];
1724
          $new_context = ctools_context_get_context_from_argument($argument, $arguments[$cid]);
1725
        }
1726
        break;
1727

    
1728
      case 'context':
1729
        if (!empty($arguments[$cid])) {
1730
          $context_info = $context->placeholder['conf'];
1731
          $new_context = ctools_context_get_context_from_context($context_info, 'requiredcontext', $arguments[$cid]);
1732
        }
1733
        break;
1734
    }
1735

    
1736
    if ($new_context && empty($new_context->empty)) {
1737
      $contexts[$cid] = $new_context;
1738
    }
1739
  }
1740

    
1741
  return $contexts;
1742
}
1743

    
1744
/**
1745
 * Provide a form array for getting data to replace placeholder contexts
1746
 * with real data.
1747
 */
1748
function ctools_context_replace_form(&$form, $contexts) {
1749
  foreach ($contexts as $cid => $context) {
1750
    if (empty($context->empty)) {
1751
      continue;
1752
    }
1753

    
1754
    // Get plugin info from the context which should have been set when the
1755
    // empty context was created.
1756
    $info = NULL;
1757
    $plugin = NULL;
1758
    $settings = NULL;
1759
    switch ($context->placeholder['type']) {
1760
      case 'argument':
1761
        $info = $context->placeholder['conf'];
1762
        $plugin = ctools_get_argument($info['name']);
1763
        break;
1764

    
1765
      case 'context':
1766
        $info = $context->placeholder['conf'];
1767
        $plugin = ctools_get_context($info['name']);
1768
        break;
1769
    }
1770

    
1771
    // Ask the plugin where the form is.
1772
    if ($plugin && isset($plugin['placeholder form'])) {
1773
      if (is_array($plugin['placeholder form'])) {
1774
        $form[$cid] = $plugin['placeholder form'];
1775
      }
1776
      else {
1777
        if (function_exists($plugin['placeholder form'])) {
1778
          $widget = $plugin['placeholder form']($info);
1779
          if ($widget) {
1780
            $form[$cid] = $widget;
1781
          }
1782
        }
1783
      }
1784

    
1785
      if (!empty($form[$cid])) {
1786
        $form[$cid]['#title'] = t('@identifier (@keyword)', array(
1787
          '@keyword' => '%' . $context->keyword,
1788
          '@identifier' => $context->identifier,
1789
        ));
1790
      }
1791
    }
1792
  }
1793
}
1794

    
1795
// ---------------------------------------------------------------------------
1796
// Functions related to loading access control plugins.
1797
/**
1798
 * Fetch metadata on a specific access control plugin.
1799
 *
1800
 * @param $name
1801
 *   Name of a plugin.
1802
 *
1803
 * @return array
1804
 *   An array with information about the requested access control plugin.
1805
 */
1806

    
1807
function ctools_get_access_plugin($name) {
1808
  ctools_include('plugins');
1809
  return ctools_get_plugins('ctools', 'access', $name);
1810
}
1811

    
1812
/**
1813
 * Fetch metadata for all access control plugins.
1814
 *
1815
 * @return array
1816
 *   An array of arrays with information about all available access control plugins.
1817
 */
1818
function ctools_get_access_plugins() {
1819
  ctools_include('plugins');
1820
  return ctools_get_plugins('ctools', 'access');
1821
}
1822

    
1823
/**
1824
 * Fetch a list of access plugins that are available for a given list of
1825
 * contexts.
1826
 *
1827
 * If 'logged-in-user' is not in the list of contexts, it will be added as
1828
 * this is required.
1829
 *
1830
 * @param array $contexts
1831
 *   Array of ctools_context objects with which to select access plugins.
1832
 *
1833
 * @return array
1834
 *   Array of applicable access plugins. Can be empty.
1835
 */
1836
function ctools_get_relevant_access_plugins($contexts) {
1837
  if (!isset($contexts['logged-in-user'])) {
1838
    $contexts['logged-in-user'] = ctools_access_get_loggedin_context();
1839
  }
1840

    
1841
  $all_plugins = ctools_get_access_plugins();
1842
  $plugins = array();
1843
  foreach ($all_plugins as $id => $plugin) {
1844
    if (!empty($plugin['required context'])
1845
      && !ctools_context_match_requirements($contexts, $plugin['required context'])
1846
    ) {
1847
      continue;
1848
    }
1849
    $plugins[$id] = $plugin;
1850
  }
1851

    
1852
  return $plugins;
1853
}
1854

    
1855
/**
1856
 * Create a context for the logged in user.
1857
 */
1858
function ctools_access_get_loggedin_context() {
1859
  $context = ctools_context_create('entity:user', array('type' => 'current'), TRUE);
1860
  $context->identifier = t('Logged in user');
1861
  $context->keyword = 'viewer';
1862
  $context->id = 0;
1863

    
1864
  return $context;
1865
}
1866

    
1867
/**
1868
 * Get a summary of an access plugin's settings.
1869
 *
1870
 * @return string
1871
 *   The summary text.
1872
 */
1873
function ctools_access_summary($plugin, $contexts, $test) {
1874
  if (!isset($contexts['logged-in-user'])) {
1875
    $contexts['logged-in-user'] = ctools_access_get_loggedin_context();
1876
  }
1877

    
1878
  $description = '';
1879
  if ($function = ctools_plugin_get_function($plugin, 'summary')) {
1880
    $required_context = isset($plugin['required context']) ? $plugin['required context'] : array();
1881
    $context = isset($test['context']) ? $test['context'] : array();
1882
    $selected_context = ctools_context_select($contexts, $required_context, $context);
1883
    $description = $function($test['settings'], $selected_context, $plugin);
1884
  }
1885

    
1886
  if (!empty($test['not'])) {
1887
    $description = "NOT ($description)";
1888
  }
1889

    
1890
  return $description;
1891
}
1892

    
1893
/**
1894
 * Get a summary of a group of access plugin's settings.
1895
 *
1896
 * @param $access
1897
 *   An array of settings theoretically set by the user, including the array
1898
 *   of plugins to check:
1899
 *    - 'plugins': the array of plugin metadata info to check
1900
 *    - 'logic': (optional) either 'and' or 'or', indicating how to combine
1901
 *      restrictions. Defaults to 'or'.
1902
 * @param array $contexts
1903
 *   An array of zero or more contexts that may be used to determine if
1904
 *   the user has access.
1905
 *
1906
 * @return string
1907
 *   The summary text. Can be NULL if there are no plugins defined.
1908
 */
1909
function ctools_access_group_summary($access, $contexts) {
1910
  if (empty($access['plugins']) || !is_array($access['plugins'])) {
1911
    return NULL;
1912
  }
1913

    
1914
  $descriptions = array();
1915
  foreach ($access['plugins'] as $id => $test) {
1916
    $plugin = ctools_get_access_plugin($test['name']);
1917
    $descriptions[] = ctools_access_summary($plugin, $contexts, $test);
1918
  }
1919

    
1920
  $separator =
1921
    (isset($access['logic']) && $access['logic'] === 'and')
1922
      ? t(', and ') : t(', or ');
1923
  return implode($separator, $descriptions);
1924
}
1925

    
1926
/**
1927
 * Determine if the current user has access via a plugin.
1928
 *
1929
 * @param array $settings
1930
 *   An array of settings theoretically set by the user, including the array
1931
 *   of plugins to check:
1932
 *    - 'plugins': the array of plugin metadata info to check
1933
 *    - 'logic': (optional) either 'and' or 'or', indicating how to combine
1934
 *      restrictions. The 'or' case is not fully implemented and returns the
1935
 *      input contexts unchanged.
1936
 *
1937
 * @param array $contexts
1938
 *   An array of zero or more contexts that may be used to determine if
1939
 *   the user has access.
1940
 *
1941
 * @return bool
1942
 *   TRUE if access is granted, FALSE if otherwise.
1943
 */
1944
function ctools_access($settings, $contexts = array()) {
1945
  if (empty($settings['plugins'])) {
1946
    return TRUE;
1947
  }
1948

    
1949
  if (!isset($settings['logic'])) {
1950
    $settings['logic'] = 'and';
1951
  }
1952

    
1953
  if (!isset($contexts['logged-in-user'])) {
1954
    $contexts['logged-in-user'] = ctools_access_get_loggedin_context();
1955
  }
1956

    
1957
  foreach ($settings['plugins'] as $test) {
1958
    $pass = FALSE;
1959
    $plugin = ctools_get_access_plugin($test['name']);
1960
    if ($plugin && $function = ctools_plugin_get_function($plugin, 'callback')) {
1961
      // Do we need just some contexts or all of them?
1962
      if (!empty($plugin['all contexts'])) {
1963
        $test_contexts = $contexts;
1964
      }
1965
      else {
1966
        $required_context = isset($plugin['required context']) ? $plugin['required context'] : array();
1967
        $context = isset($test['context']) ? $test['context'] : array();
1968
        $test_contexts = ctools_context_select($contexts, $required_context, $context);
1969
      }
1970

    
1971
      $pass = $function($test['settings'], $test_contexts, $plugin);
1972
      if (!empty($test['not'])) {
1973
        $pass = !$pass;
1974
      }
1975
    }
1976

    
1977
    if ($pass && $settings['logic'] == 'or') {
1978
      // Pass if 'or' and this rule passed.
1979
      return TRUE;
1980
    }
1981
    elseif (!$pass && $settings['logic'] == 'and') {
1982
      // Fail if 'and' and this rule failed.
1983
      return FALSE;
1984
    }
1985
  }
1986

    
1987
  // Return TRUE if logic was and, meaning all rules passed.
1988
  // Return FALSE if logic was or, meaning no rule passed.
1989
  return ($settings['logic'] === 'and');
1990
}
1991

    
1992
/**
1993
 * Create default settings for a new access plugin.
1994
 *
1995
 * @param $plugin
1996
 *   The access plugin being used.
1997
 *
1998
 * @return array
1999
 *   A default configured test that should be placed in $access['plugins'];
2000
 */
2001
function ctools_access_new_test($plugin) {
2002
  $test = array(
2003
    'name' => $plugin['name'],
2004
    'settings' => array(),
2005
  );
2006

    
2007
  // Set up required context defaults.
2008
  if (isset($plugin['required context'])) {
2009
    if (is_object($plugin['required context'])) {
2010
      $test['context'] = '';
2011
    }
2012
    else {
2013
      $test['context'] = array();
2014
      foreach ($plugin['required context'] as $required) {
2015
        $test['context'][] = '';
2016
      }
2017
    }
2018
  }
2019

    
2020
  $default = NULL;
2021
  if (isset($plugin['default'])) {
2022
    $default = $plugin['default'];
2023
  }
2024
  elseif (isset($plugin['defaults'])) {
2025
    $default = $plugin['defaults'];
2026
  }
2027

    
2028
  // Setup plugin defaults.
2029
  if (isset($default)) {
2030
    if (is_array($default)) {
2031
      $test['settings'] = $default;
2032
    }
2033
    elseif (function_exists($default)) {
2034
      $test['settings'] = $default();
2035
    }
2036
    else {
2037
      $test['settings'] = array();
2038
    }
2039
  }
2040

    
2041
  return $test;
2042
}
2043

    
2044
/**
2045
 * Apply restrictions to contexts based upon the access control configured.
2046
 *
2047
 * These restrictions allow the UI to not show content that may not be relevant
2048
 * to all types of a particular context.
2049
 *
2050
 * @param array $settings
2051
 *   Array of keys specifying the settings:
2052
 *    - 'plugins': the array of plugin metadata info to check. If not set, or
2053
 *      not an array, the function returns with no action.
2054
 *    - 'logic': (optional) either 'and' or 'or', indicating how to combine
2055
 *      restrictions. Defaults to 'and'.
2056
 *      The 'or' case is not fully implemented and returns with no action if
2057
 *      there is more than one plugin.
2058
 *
2059
 * @param array $contexts
2060
 *   Array of available contexts.
2061
 */
2062
function ctools_access_add_restrictions($settings, $contexts) {
2063
  if (empty($settings['plugins']) || !is_array($settings['plugins'])) {
2064
    return;
2065
  }
2066

    
2067
  if (!isset($settings['logic'])) {
2068
    $settings['logic'] = 'and';
2069
  }
2070

    
2071
  // We're not going to try to figure out restrictions on the or.
2072
  if ($settings['logic'] === 'or' && count($settings['plugins']) > 1) {
2073
    return;
2074
  }
2075

    
2076
  foreach ($settings['plugins'] as $test) {
2077
    $plugin = ctools_get_access_plugin($test['name']);
2078
    // $plugin is 'array()' on error.
2079
    if ($plugin
2080
      && $function = ctools_plugin_get_function($plugin, 'restrictions')
2081
    ) {
2082
      $required_context = isset($plugin['required context']) ? $plugin['required context'] : array();
2083
      $context = isset($test['context']) ? $test['context'] : array();
2084
      $contexts = ctools_context_select($contexts, $required_context, $context);
2085

    
2086
      if ($contexts !== FALSE) {
2087
        $function($test['settings'], $contexts);
2088
      }
2089
    }
2090
  }
2091
}