aboutsummaryrefslogtreecommitdiff
path: root/engine/lib/access.php
blob: 4b295fd34978bea88ab6f55459c723046b644282 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
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
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
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
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
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
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
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
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
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
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
877
878
<?php
/**
 * Elgg access permissions
 * For users, objects, collections and all metadata
 *
 * @package Elgg
 * @subpackage Core

 * @author Curverider Ltd

 * @link http://elgg.org/
 */

/**
 * Temporary class used to determing if access is being ignored
 */
class ElggAccess {
	/**
	 * Bypass Elgg's access control if true.
	 * @var bool
	 */
	private $ignore_access;

	/**
	 * Get current ignore access setting.
	 * @return bool
	 */
	public function get_ignore_access() {
		return $this->ignore_access;
	}

	/**
	 * Set ignore access.
	 *
	 * @param $ignore bool true || false to ignore
	 * @return bool Previous setting
	 */
	public function set_ignore_access($ignore = true) {
		$prev = $this->ignore_access;
		$this->ignore_access = $ignore;

		return $prev;
	}
}


/**
 * Return a string of access_ids for $user_id appropriate for inserting into an SQL IN clause.
 *
 * @uses get_access_array
 * @param int $user_id User ID; defaults to currently logged in user
 * @param int $site_id Site ID; defaults to current site
 * @param boolean $flush If set to true, will refresh the access list from the database
 * @return string A list of access collections suitable for injection in an SQL call
 */
function get_access_list($user_id = 0, $site_id = 0, $flush = false) {
	global $CONFIG, $init_finished, $SESSION;
	static $access_list;

	if (!isset($access_list) || !$init_finished) {
		$access_list = array();
	}

	if ($user_id == 0) {
		$user_id = $SESSION['id'];
	}

	if (($site_id == 0) && (isset($CONFIG->site_id))) {
		$site_id = $CONFIG->site_id;
	}
	$user_id = (int) $user_id;
	$site_id = (int) $site_id;

	if (isset($access_list[$user_id])) {
		return $access_list[$user_id];
	}

	$access_list[$user_id] = "(" . implode(",", get_access_array($user_id, $site_id, $flush)) . ")";

	return $access_list[$user_id];
}

/**
 * Gets an array of access restrictions the given user is allowed to see on this site
 *
 * @param int $user_id User ID; defaults to currently logged in user
 * @param int $site_id Site ID; defaults to current site
 * @param boolean $flush If set to true, will refresh the access list from the database
 * @return array An array of access collections suitable for injection in an SQL call
 */
function get_access_array($user_id = 0, $site_id = 0, $flush = false) {
	global $CONFIG, $init_finished;

	// @todo everything from the db is cached.
	// this cache might be redundant.
	static $access_array;

	if (!isset($access_array) || (!isset($init_finished)) || (!$init_finished)) {
		$access_array = array();
	}

	if ($user_id == 0) {
		$user_id = get_loggedin_userid();
	}

	if (($site_id == 0) && (isset($CONFIG->site_guid))) {
		$site_id = $CONFIG->site_guid;
	}

	$user_id = (int) $user_id;
	$site_id = (int) $site_id;

	if (empty($access_array[$user_id]) || $flush == true) {
		$tmp_access_array = array(ACCESS_PUBLIC);
		if (isloggedin()) {
			$tmp_access_array[] = ACCESS_LOGGED_IN;

			// The following can only return sensible data if the user is logged in.

			// Get ACL memberships
			$query = "SELECT am.access_collection_id FROM {$CONFIG->dbprefix}access_collection_membership am ";
			$query .= " LEFT JOIN {$CONFIG->dbprefix}access_collections ag ON ag.id = am.access_collection_id ";
			$query .= " WHERE am.user_guid = {$user_id} AND (ag.site_guid = {$site_id} OR ag.site_guid = 0)";

			if ($collections = get_data($query)) {
				foreach($collections as $collection) {
					if (!empty($collection->access_collection_id)) {
						$tmp_access_array[] = $collection->access_collection_id;
					}
				}
			}

			// Get ACLs owned.
			$query = "SELECT ag.id FROM {$CONFIG->dbprefix}access_collections ag  ";
			$query .= " WHERE ag.owner_guid = {$user_id} AND (ag.site_guid = {$site_id} OR ag.site_guid = 0)";

			if ($collections = get_data($query)) {
				foreach($collections as $collection) {
					if (!empty($collection->id)) {
						$tmp_access_array[] = $collection->id;
					}
				}
			}

			$ignore_access = elgg_check_access_overrides($user_id);

			if ($ignore_access == true) {
				$tmp_access_array[] = ACCESS_PRIVATE;
			}

			$access_array[$user_id] = $tmp_access_array;
		} else {
			// No user id logged in so we can only access public info
			$tmp_return = $tmp_access_array;
		}

	} else {

		$tmp_access_array = $access_array[$user_id];
	}

	$tmp_return = $access_array[$user_id];

	return trigger_plugin_hook('access:collections:read','user',array('user_id' => $user_id, 'site_id' => $site_id),$tmp_access_array);
}

/**
 * Gets the default access permission for new content
 *
 * @return int default access id (see ACCESS defines in elgglib.php)
 */
function get_default_access(ElggUser $user = null) {
	global $CONFIG;

	if (!$CONFIG->allow_user_default_access) {
		return $CONFIG->default_access;
	}

	if (!($user) || (!$user = get_loggedin_user())) {
		return $CONFIG->default_access;
	}

	if (false !== ($default_access = $user->getPrivateSetting('elgg_default_access'))) {
		return $default_access;
	} else {
		return $CONFIG->default_access;
	}
}

/**
 * Override the default behaviour and allow results to show hidden entities as well.
 * THIS IS A HACK.
 *
 * TODO: Replace this with query object!
 */
$ENTITY_SHOW_HIDDEN_OVERRIDE = false;

/**
 * This will be replaced. Do not use in plugins!
 *
 * @param bool $show
 */
function access_show_hidden_entities($show_hidden) {
	global $ENTITY_SHOW_HIDDEN_OVERRIDE;
	$ENTITY_SHOW_HIDDEN_OVERRIDE = $show_hidden;
}

/**
 * This will be replaced. Do not use in plugins!
 */
function access_get_show_hidden_status() {
	global $ENTITY_SHOW_HIDDEN_OVERRIDE;
	return $ENTITY_SHOW_HIDDEN_OVERRIDE;
}

/**
 * Add annotation restriction
 *
 * Returns an SQL fragment that is true (or optionally false) if the given user has
 * added an annotation with the given name to the given entity.
 *
 * TODO: This is fairly generic so perhaps it could be moved to annotations.php
 *
 * @param string $annotation_name name of the annotation
	* @param string $entity_guid SQL string that evaluates to the GUID of the entity the annotation should be attached to
	* @param string $owner_guid SQL string that evaluates to the GUID of the owner of the annotation	 	 *
	* @param boolean $exists If set to true, will return true if the annotation exists, otherwise returns false
	* @return string An SQL fragment suitable for inserting into a WHERE clause
 */
function get_annotation_sql($annotation_name, $entity_guid, $owner_guid, $exists) {
	global $CONFIG;

	if ($exists) {
		$not = '';
	} else {
		$not = 'NOT';
	}

	$sql = <<<END
$not EXISTS (SELECT * FROM {$CONFIG->dbprefix}annotations a
INNER JOIN {$CONFIG->dbprefix}metastrings ms ON (a.name_id = ms.id)
WHERE ms.string = '$annotation_name'
AND a.entity_guid = $entity_guid
AND a.owner_guid = $owner_guid)
END;
	return $sql;
}

/**
 * Add access restriction sql code to a given query.
 * Note that if this code is executed in privileged mode it will return blank.
 * @TODO: DELETE once Query classes are fully integrated
 *
 * @param string $table_prefix Optional table. prefix for the access code.
 * @param int $owner
 */
function get_access_sql_suffix($table_prefix = '', $owner = null) {
	global $ENTITY_SHOW_HIDDEN_OVERRIDE, $CONFIG;

	$sql = "";
	$friends_bit = "";
	$enemies_bit = "";

	if ($table_prefix) {
			$table_prefix = sanitise_string($table_prefix) . ".";
	}

	if (!isset($owner)) {
		$owner = get_loggedin_userid();
	}

	if (!$owner) {
		$owner = -1;
	}

	$ignore_access = elgg_check_access_overrides($owner);
	$access = get_access_list($owner);

	if ($ignore_access) {
		$sql = " (1 = 1) ";
	} else if ($owner != -1) {
		$friends_bit = "{$table_prefix}access_id = " . ACCESS_FRIENDS . "
			AND {$table_prefix}owner_guid IN (
				SELECT guid_one FROM {$CONFIG->dbprefix}entity_relationships
				WHERE relationship='friend' AND guid_two=$owner
			)";

		$friends_bit = '('.$friends_bit.') OR ';

		if ((isset($CONFIG->user_block_and_filter_enabled)) && ($CONFIG->user_block_and_filter_enabled)) {
			// check to see if the user is in the entity owner's block list
			// or if the entity owner is in the user's filter list
			// if so, disallow access
			$enemies_bit = get_annotation_sql('elgg_block_list', "{$table_prefix}owner_guid", $owner, false);
			$enemies_bit = '('
				. $enemies_bit
				. '	AND ' . get_annotation_sql('elgg_filter_list', $owner, "{$table_prefix}owner_guid", false)
			. ')';
		}
	}

	if (empty($sql)) {
		$sql = " $friends_bit ({$table_prefix}access_id IN {$access}
			OR ({$table_prefix}owner_guid = {$owner})
			OR (
				{$table_prefix}access_id = " . ACCESS_PRIVATE . "
				AND {$table_prefix}owner_guid = $owner
			)
		)";
	}

	if ($enemies_bit) {
		$sql = "$enemies_bit AND ($sql)";
	}

	if (!$ENTITY_SHOW_HIDDEN_OVERRIDE)
		$sql .= " and {$table_prefix}enabled='yes'";
	return '('.$sql.')';
}

/**
 * Determines whether the given user has access to the given entity
 *
 * @param ElggEntity $entity The entity to check access for.
 * @param ElggUser $user Optionally the user to check access for.
 *
 * @return boolean True if the user can access the entity
 */
function has_access_to_entity($entity, $user = null) {
	global $CONFIG;

	if (!isset($user)) {
		$access_bit = get_access_sql_suffix("e");
	} else {
		$access_bit = get_access_sql_suffix("e", $user->getGUID());
	}

	$query = "SELECT guid from {$CONFIG->dbprefix}entities e WHERE e.guid = " . $entity->getGUID();
	$query .= " AND " . $access_bit; // Add access controls
	if (get_data($query)) {
		return true;
	} else {
		return false;
	}
}

/**
 * Returns an array of access permissions that the specified user is allowed to save objects with.
 * Permissions are of the form ('id' => 'Description')
 *
 * @param int $user_id The user's GUID.
 * @param int $site_id The current site.
 * @param true|false $flush If this is set to true, this will shun any cached version
 *
 * @return array List of access permissions
 */
function get_write_access_array($user_id = 0, $site_id = 0, $flush = false) {
	global $CONFIG;
	//@todo this is probably not needed since caching happens at the DB level.
	static $access_array;

	if ($user_id == 0) {
		$user_id = get_loggedin_userid();
	}

	if (($site_id == 0) && (isset($CONFIG->site_id))) {
		$site_id = $CONFIG->site_id;
	}

	$user_id = (int) $user_id;
	$site_id = (int) $site_id;

	if (empty($access_array[$user_id]) || $flush == true) {
		$query = "SELECT ag.* FROM {$CONFIG->dbprefix}access_collections ag ";
		$query .= " WHERE (ag.site_guid = {$site_id} OR ag.site_guid = 0)";
		$query .= " AND (ag.owner_guid = {$user_id})";
		$query .= " AND ag.id >= 3";

		$tmp_access_array = array(0 => elgg_echo("PRIVATE"), ACCESS_FRIENDS => elgg_echo("access:friends:label"), 1 => elgg_echo("LOGGED_IN"), 2 => elgg_echo("PUBLIC"));
		if ($collections = get_data($query)) {
			foreach($collections as $collection) {
				$tmp_access_array[$collection->id] = $collection->name;
			}
		}

		$access_array[$user_id] = $tmp_access_array;
	} else {
		$tmp_access_array = $access_array[$user_id];
	}

	$tmp_access_array = trigger_plugin_hook('access:collections:write','user',array('user_id' => $user_id, 'site_id' => $site_id),$tmp_access_array);

	return $tmp_access_array;
}

/**
 * Creates a new access control collection owned by the specified user.
 *
 * @param string $name The name of the collection.
 * @param int $owner_guid The GUID of the owner (default: currently logged in user).
 * @param int $site_guid The GUID of the site (default: current site).
 *
 * @return int|false Depending on success (the collection ID if successful).
 */
function create_access_collection($name, $owner_guid = 0, $site_guid = 0) {
	global $CONFIG;

	$name = trim($name);
	if (empty($name)) {
		return false;
	}

	if ($owner_guid == 0) {
		$owner_guid = get_loggedin_userid();
	}
	if (($site_id == 0) && (isset($CONFIG->site_guid))) {
		$site_id = $CONFIG->site_guid;
	}
	$name = sanitise_string($name);

	$q = "INSERT INTO {$CONFIG->dbprefix}access_collections
		SET name = '{$name}',
			owner_guid = {$owner_guid},
			site_guid = {$site_id}";
	if (!$id = insert_data($q)) {
		return false;
	}

	$params = array(
		'collection_id' => $id
	);

	if (!trigger_plugin_hook('access:collections:addcollection', 'collection', $params, true)) {
		return false;
	}

	return $id;
}

/**
 * Updates the membership in an access collection.
 *
 * @param int $collection_id The ID of the collection.
 * @param array $members Array of member GUIDs
 * @return true|false Depending on success
 */
function update_access_collection($collection_id, $members) {
	global $CONFIG;

	$collection_id = (int) $collection_id;
	$members = (is_array($members)) ? $members : array();

	$collections = get_write_access_array();

	if (array_key_exists($collection_id, $collections)) {
		$cur_members = get_members_of_access_collection($collection_id, true);
		$cur_members = (is_array($cur_members)) ? $cur_members : array();

		$remove_members = array_diff($cur_members, $members);
		$add_members = array_diff($members, $cur_members);

		$params = array(
			'collection_id' => $collection_id,
			'members' => $members,
			'add_members' => $add_members,
			'remove_members' => $remove_members
		);

		foreach ($add_members as $guid) {
			add_user_to_access_collection($guid, $collection_id);
		}

		foreach ($remove_members as $guid) {
			remove_user_from_access_collection($guid, $collection_id);
		}

		return true;
	}

	return false;
}

/**
 * Deletes a specified access collection
 *
 * @param int $collection_id The collection ID
 * @return true|false Depending on success
 */
function delete_access_collection($collection_id) {

	$collection_id = (int) $collection_id;
	$collections = get_write_access_array();
	$params = array('collection_id' => $collection_id);

	if (!trigger_plugin_hook('access:collections:deletecollection', 'collection', $params, true)) {
		return false;
	}

	if (array_key_exists($collection_id, $collections)) {
		global $CONFIG;
		delete_data("delete from {$CONFIG->dbprefix}access_collection_membership where access_collection_id = {$collection_id}");
		delete_data("delete from {$CONFIG->dbprefix}access_collections where id = {$collection_id}");
		return true;
	} else {
		return false;
	}

}

/**
 * Get a specified access collection
 *
 * @param int $collection_id The collection ID
 * @return array|false Depending on success
 */
function get_access_collection($collection_id) {
	global $CONFIG;
	$collection_id = (int) $collection_id;

	$get_collection = get_data_row("SELECT * FROM {$CONFIG->dbprefix}access_collections WHERE id = {$collection_id}");

	return $get_collection;
}

/**
 * Adds a user to the specified user collection
 *
 * @param int $user_guid The GUID of the user to add
 * @param int $collection_id The ID of the collection to add them to
 * @return true|false Depending on success
 */
function add_user_to_access_collection($user_guid, $collection_id) {
	$collection_id = (int) $collection_id;
	$user_guid = (int) $user_guid;
	$collections = get_write_access_array();

	if (!($collection = get_access_collection($collection_id)))
		return false;

	if ((array_key_exists($collection_id, $collections) || $collection->owner_guid == 0)
			&& $user = get_user($user_guid)) {
		global $CONFIG;

		$params = array(
			'collection_id' => $collection_id,
			'user_guid' => $user_guid
		);

		if (!trigger_plugin_hook('access:collections:add_user', 'collection', $params, true)) {
			return false;
		}

		try {
			insert_data("insert into {$CONFIG->dbprefix}access_collection_membership set access_collection_id = {$collection_id}, user_guid = {$user_guid}");
		} catch (DatabaseException $e) {
			// nothing.
		}
		return true;

	}

	return false;
}

/**
 * Removes a user from an access collection
 *
 * @param int $user_guid The user GUID
 * @param int $collection_id The access collection ID
 * @return true|false Depending on success
 */
function remove_user_from_access_collection($user_guid, $collection_id) {
	$collection_id = (int) $collection_id;
	$user_guid = (int) $user_guid;
	$collections = get_write_access_array();

	if (!($collection = get_access_collection($collection_id)))
		return false;

	if ((array_key_exists($collection_id, $collections) || $collection->owner_guid == 0) && $user = get_user($user_guid)) {
		global $CONFIG;
		$params = array(
			'collection_id' => $collection_id,
			'user_guid' => $user_guid
		);

		if (!trigger_plugin_hook('access:collections:remove_user', 'collection', $params, true)) {
			return false;
		}

		delete_data("delete from {$CONFIG->dbprefix}access_collection_membership where access_collection_id = {$collection_id} and user_guid = {$user_guid}");
		return true;

	}

	return false;
}

/**
 * Get all of a users collections
 *
 * @param int $owner_guid The user ID
 * @return true|false Depending on success
 */
function get_user_access_collections($owner_guid) {
	global $CONFIG;
	$owner_guid = (int) $owner_guid;

	$collections = get_data("SELECT * FROM {$CONFIG->dbprefix}access_collections WHERE owner_guid = {$owner_guid}");

	return $collections;
}

/**
 * Get all of members of a friend collection
 *
 * @param int $collection The collection's ID
 * @param true|false $idonly If set to true, will only return the members' IDs (default: false)
 * @return ElggUser entities if successful, false if not
 */
function get_members_of_access_collection($collection, $idonly = false) {
	global $CONFIG;
	$collection = (int)$collection;

	if (!$idonly) {
		$query = "SELECT e.* FROM {$CONFIG->dbprefix}access_collection_membership m JOIN {$CONFIG->dbprefix}entities e ON e.guid = m.user_guid WHERE m.access_collection_id = {$collection}";
		$collection_members = get_data($query, "entity_row_to_elggstar");
	} else {
		$query = "SELECT e.guid FROM {$CONFIG->dbprefix}access_collection_membership m JOIN {$CONFIG->dbprefix}entities e ON e.guid = m.user_guid WHERE m.access_collection_id = {$collection}";
		$collection_members = get_data($query);
		foreach($collection_members as $key => $val) {
			$collection_members[$key] = $val->guid;
		}
	}

	return $collection_members;
}

/**
 * Displays a user's access collections, using the friends/collections view
 *
 * @param int $owner_guid The GUID of the owning user
 * @return string A formatted rendition of the collections
 */
function elgg_view_access_collections($owner_guid) {
	if ($collections = get_user_access_collections($owner_guid)) {
		foreach($collections as $key => $collection) {
			$collections[$key]->members = get_members_of_access_collection($collection->id, true);
			$collections[$key]->entities = get_user_friends($owner_guid,"",9999);
		}
	}

	return elgg_view('friends/collections',array('collections' => $collections));
}

/**
 * Get entities with the specified access collection id.
 *
 * @deprecated 1.7. Use elgg_get_entities_from_access_id()
 *
 * @param $collection_id
 * @param $entity_type
 * @param $entity_subtype
 * @param $owner_guid
 * @param $limit
 * @param $offset
 * @param $order_by
 * @param $site_guid
 * @param $count
 * @return unknown_type
 */
function get_entities_from_access_id($collection_id, $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $offset = 0, $order_by = "", $site_guid = 0, $count = false) {
	// log deprecated warning
	elgg_log('get_entities_from_access_id() was deprecated in 1.7 by elgg_get_entities()!', 'WARNING');

	if (!$collection_id) {
		return FALSE;
	}

	// build the options using given parameters
	$options = array();
	$options['limit'] = $limit;
	$options['offset'] = $offset;
	$options['count'] = $count;

	if ($entity_type) {
		$options['type'] = sanitise_string($entity_type);
	}

	if ($entity_subtype) {
		$options['subtype'] = $entity_subtype;
	}

	if ($site_guid) {
		$options['site_guid'] = $site_guid;
	}

	if ($order_by) {
		$options['order_by'] = sanitise_string("e.time_created, $order_by");
	}

	if ((is_array($owner_guid) && (count($owner_guid)))) {
		$options['owner_guids'] = array();
		foreach($owner_guid as $guid) {
			$options['owner_guids'][] = $guid;
		}
	}

	if ($site_guid) {
		$options['site_guid'] = $site_guid;
	}

	$options['access_id'] = $collection_id;

	return elgg_get_entities_from_access_id($options);
}

/**
 * Retrieve entities for a given access collection
 *
 * @param int $collection_id
 * @param array $options @see elgg_get_entities()
 * @return array
 * @since 1.7
 */
function elgg_get_entities_from_access_id(array $options=array()) {
	// restrict the resultset to access collection provided
	if (!isset($options['access_id'])) {
		return FALSE;
	}

	// @todo add support for an array of collection_ids
	$where = "e.access_id = '{$options['access_id']}'";
	if (isset($options['wheres'])) {
		if (is_array($options['wheres'])) {
			$options['wheres'][] = $where;
		} else {
			$options['wheres'] = array($options['wheres'], $where);
		}
	} else {
		$options['wheres'] = array($where);
	}

	// return entities with the desired options
	return elgg_get_entities($options);
}

/**
 * Lists entities from an access collection
 *
 * @param $collection_id
 * @param $entity_type
 * @param $entity_subtype
 * @param $owner_guid
 * @param $limit
 * @param $fullview
 * @param $viewtypetoggle
 * @param $pagination
 * @return str
 */
function list_entities_from_access_id($collection_id, $entity_type = "", $entity_subtype = "", $owner_guid = 0, $limit = 10, $fullview = true, $viewtypetoggle = true, $pagination = true) {
	$offset = (int) get_input('offset');
	$limit = (int) $limit;
	$count = get_entities_from_access_id($collection_id, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", 0, true);
	$entities = get_entities_from_access_id($collection_id, $entity_type, $entity_subtype, $owner_guid, $limit, $offset, "", 0, false);

	return elgg_view_entity_list($entities, $count, $offset, $limit, $fullview, $viewtypetoggle, $pagination);
}

/**
 * Return a humanreadable version of an entity's access level
 *
 * @param $entity_accessid (int) The entity's access id
 * @return string e.g. Public, Private etc
 **/
function get_readable_access_level($entity_accessid){
	$access = (int) $entity_accessid;
	//get the access level for object in readable string
	$options = get_write_access_array();
	foreach($options as $key => $option) {
		if($key == $access){
			$entity_acl = htmlentities($option, ENT_QUOTES, 'UTF-8');
			return $entity_acl;
			break;
		}
	}
	return false;
}

/**
 * Set if entity access system should be ignored.
 *
 * @return bool Previous ignore_access setting.
 */
function elgg_set_ignore_access($ignore = true) {
	$elgg_access = elgg_get_access_object();
	return $elgg_access->set_ignore_access($ignore);
}

/**
 * Get current ignore access setting.
 *
 * @return bool
 */
function elgg_get_ignore_access() {
	return elgg_get_access_object()->get_ignore_access();
}

/**
 * Decides if the access system is being ignored.
 *
 * @return bool
 */
function elgg_check_access_overrides($user_guid = null) {
	if (!$user_guid || $user_guid <= 0) {
		$is_admin = false;
	} else {
		$is_admin = elgg_is_admin_user($user_guid);
	}

	return ($is_admin || elgg_get_ignore_access());
}

/**
 * Returns the ElggAccess object.
 *
 * @return ElggAccess
 */
function elgg_get_access_object() {
	static $elgg_access;

	if (!$elgg_access) {
		$elgg_access = new ElggAccess();
	}

	return $elgg_access;
}

global $init_finished;
$init_finished = false;

/**
 * A quick and dirty way to make sure the access permissions have been correctly set up
 *
 */
function access_init() {
	global $init_finished;
	$init_finished = true;
}

/**
 * Override permissions system
 *
 * @return true|null
 */
function elgg_override_permissions_hook($hook, $type, $returnval, $params) {
	$user_guid = get_loggedin_userid();

	// check for admin
	if ($user_guid && elgg_is_admin_user($user_guid)) {
		return true;
	}

	// check access overrides
	if ((elgg_check_access_overrides($user_guid))) {
		return true;
	}

	// consult other hooks
	return NULL;
}

// This function will let us know when 'init' has finished
register_elgg_event_handler('init', 'system', 'access_init', 9999);

// For overrided permissions
register_plugin_hook('permissions_check', 'all', 'elgg_override_permissions_hook');
register_plugin_hook('container_permissions_check', 'all', 'elgg_override_permissions_hook');