aboutsummaryrefslogtreecommitdiff
path: root/engine/lib/entities.php
blob: ea74898c3041575a3de3c9a5a5a025272dd96695 (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
<?php
	/**
	 * Elgg entities.
	 * Functions to manage all elgg entities (sites, collections, objects and users).
	 * 
	 * @package Elgg
	 * @subpackage Core
	 * @license http://www.gnu.org/licenses/old-licenses/gpl-2.0.html GNU Public License version 2
	 * @author Marcus Povey <marcus@dushka.co.uk>
	 * @copyright Curverider Ltd 2008
	 * @link http://elgg.org/
	 */

	/**
	 * @class ElggEntity The elgg entity superclass
	 * This class holds methods for accessing the main entities table.
	 * @author Marcus Povey <marcus@dushka.co.uk>
	 */
	abstract class ElggEntity implements Exportable
	{
		/** 
		 * The main attributes of an entity.
		 * Blank entries for all database fields should be created by the constructor.
		 * Subclasses should add to this in their constructors.
		 * Any field not appearing in this will be viewed as a 
		 */
		protected $attributes;
				
		/**
		 * Initialise the attributes array. 
		 * This is vital to distinguish between metadata and base parameters.
		 * 
		 * Place your base parameters here.
		 */
		protected function initialise_attributes()
		{
			// Create attributes array if not already created
			if (!is_array($this->attributes)) $this->attributes = array();
			
			$this->attributes['guid'] = "";
			$this->attributes['type'] = "";
			$this->attributes['subtype'] = "";
			$this->attributes['owner_guid'] = 0;
			$this->attributes['access_id'] = 0;
			$this->attributes['time_created'] = "";
			$this->attributes['time_updated'] = "";
		}
				
		/**
		 * Return the value of a given key.
		 * If $name is a key field (as defined in $this->attributes) that value is returned, otherwise it will
		 * then look to see if the value is in this object's metadata.
		 * 
		 * Q: Why are we not using __get overload here?
		 * A: Because overload operators cause problems during subclassing, so we put the code here and
		 * create overloads in subclasses. 
		 * 
		 * @param string $name
		 * @return mixed Returns the value of a given value, or null.
		 */
		public function get($name)
		{
			// See if its in our base attribute
			if (isset($this->attributes[$name])) {
				return $this->attributes[$name];
			}
			
			// No, so see if its in the meta data for this entity
			$meta = $this->getMetaData($name);
			if ($meta)
				return $meta;
			
			// Can't find it, so return null
			return null;
		}

		/**
		 * Set the value of a given key, replacing it if necessary.
		 * If $name is a base attribute (as defined in $this->attributes) that value is set, otherwise it will
		 * set the appropriate item of metadata.
		 * 
		 * Note: It is important that your class populates $this->attributes with keys for all base attributes, anything
		 * not in their gets set as METADATA.
		 * 
		 * Q: Why are we not using __set overload here?
		 * A: Because overload operators cause problems during subclassing, so we put the code here and
		 * create overloads in subclasses.
		 * 
		 * @param string $name
		 * @param mixed $value  
		 */
		public function set($name, $value)
		{
			if (array_key_exists($name, $this->attributes))
			{
				// Check that we're not trying to change the guid! 
				if ((array_key_exists('guid', $this->attributes)) && ($name=='guid'))
					return false;
					
				$this->attributes[$name] = $value;
			}
			else
				return $this->setMetaData($name, $value);
			
			return true;
		}
			
		/**
		 * Get a given piece of metadata.
		 * 
		 * @param string $name
		 */
		public function getMetaData($name)
		{
			$md = get_metadata_byname($this->getGUID(), $name);
			
			if ($md)
				return $md->value;
				
			return null;
		}
		
		/**
		 * Set a piece of metadata.
		 * 
		 * @param string $name
		 * @param mixed $value
		 * @param string $value_type
		 * @return bool
		 */
		public function setMetaData($name, $value, $value_type = "")
		{
			if (is_array($value))
			{
				foreach ($value as $v)
					if (!create_metadata($this->getGUID(), $name, $v, $value_type, $this->getOwner(), true)) return false;
					
				return true;
			}
			else
				return create_metadata($this->getGUID(), $name, $value, $value_type, $this->getOwner());
		}
		
		/**
		 * Clear metadata.
		 */
		public function clearMetaData()
		{
			return clear_metadata($this->getGUID());
		}
		
		/**
		 * Adds an annotation to an entity. By default, the type is detected automatically; however, 
		 * it can also be set. Note that by default, annotations are private.
		 * 
		 * @param string $name
		 * @param mixed $value
		 * @param int $access_id
		 * @param int $owner_id
		 * @param string $vartype
		 */
		function annotate($name, $value, $access_id = 0, $owner_id = 0, $vartype = "") 
		{ 
			return create_annotation($this->getGUID(), $name, $value, $vartype, $owner_id, $access_id);
		}
		
		/**
		 * Get the annotations for an entity.
		 *
		 * @param string $name
		 * @param int $limit
		 * @param int $offset
		 */
		function getAnnotations($name, $limit = 50, $offset = 0) 
		{ 
			return get_annotations($this->getGUID(), "", "", $name, "", 0, $limit, $offset);
		}
		
		/**
		 * Remove all annotations or all annotations for this entity.
		 *
		 * @param string $name
		 */
		function clearAnnotations($name = "")
		{
			return clear_annotations($this->getGUID(), $name);
		}
		
		/**
		 * Return the annotations for the entity.
		 *
		 * @param string $name The type of annotation.
		 */
		function countAnnotations($name) 
		{ 
			return count_annotations($this->getGUID(), "","",$name);
		}

		/**
		 * Get the average of an integer type annotation.
		 *
		 * @param string $name
		 */
		function getAnnotationsAvg($name) 
		{
			return get_annotations_avg($this->getGUID(), "","",$name);
		}
		
		/**
		 * Get the sum of integer type annotations of a given name.
		 *
		 * @param string $name
		 */
		function getAnnotationsSum($name) 
		{
			return get_annotations_sum($this->getGUID(), "","",$name);
		}
		
		/**
		 * Get the minimum of integer type annotations of given name.
		 *
		 * @param string $name
		 */
		function getAnnotationsMin($name)
		{
			return get_annotations_min($this->getGUID(), "","",$name);
		}
		
		/**
		 * Get the maximum of integer type annotations of a given name.
		 *
		 * @param string $name
		 */
		function getAnnotationsMax($name)
		{
			return get_annotations_max($this->getGUID(), "","",$name);
		}
		
		public function getGUID() { return $this->get('guid'); }
		public function getOwner() { return $this->get('owner_guid'); }
		public function getType() { return $this->get('type'); }
		public function getSubtype() { return get_subtype_from_id($this->get('owner_guid')); }
		public function getTimeCreated() { return $this->get('time_created'); }
		public function getTimeUpdated() { return $this->get('time_updated'); }
		
		/**
		 * Save generic attributes to the entities table.
		 */
		public function save()
		{
			if ($this->get('guid') > 0)
				return update_entity(
					$this->get('guid'),
					$this->get('owner_guid'),
					$this->get('access_id')
				);
			else
			{ 
				$this->attributes['guid'] = create_entity($this->attributes['type'], $this->attributes['subtype'], $this->attributes['owner_guid'], $this->attributes['access_id']); // Create a new entity (nb: using attribute array directly 'cos set function does something special!)
				if (!$this->attributes['guid']) throw new IOException("Unable to save new object's base entity information!"); 
				
				return $this->attributes['guid'];
			}
		}
		
		/**
		 * Load the basic entity information and populate base attributes array.
		 * 
		 * @param int $guid 
		 */
		protected function load($guid)
		{		
			$row = get_entity_as_row($guid);
			
			if ($row)
			{
				// Create the array if necessary - all subclasses should test before creating
				if (!is_array($this->attributes)) $this->attributes = array();
				
				// Now put these into the attributes array as core values
				$objarray = (array) $row;
				foreach($objarray as $key => $value) 
					$this->attributes[$key] = $value;
				
				return true;
			}
			
			return false;
		}
		
		/**
		 * Delete this entity.
		 */
		public function delete() 
		{ 
			return delete_entity($this->get('guid'));
		}

		/**
		 * Export this class into a stdClass containing all necessary fields.
		 * Override if you wish to return more information than can be found in $this->attributes (shouldn't happen) 
		 * 
		 * @return stdClass
		 */
		public function export() 
		{ 
			$tmp = new stdClass; 
			$tmp->attributes = $this->attributes; 
			$tmp->attributes['uuid'] = guid_to_uuid($this->getGUID());
			return $tmp; 
		}
	}

	/**
	 * Return the integer ID for a given subtype, or false.
	 * 
	 * TODO: Move to a nicer place?
	 * 
	 * @param string $type
	 * @param string $subtype
	 */
	function get_subtype_id($type, $subtype)
	{
		global $CONFIG;
		
		$type = sanitise_string($type);
		$subtype = sanitise_string($subtype);
		
		$result = get_data_row("SELECT * from {$CONFIG->dbprefix}entity_subtypes where type='$type' and subtype='$subtype'");
		if ($result)
			return $result->id;
		
		return 0;
	}
	
	/**
	 * For a given subtype ID, return its identifier text.
	 *  
	 * TODO: Move to a nicer place?
	 * 
	 * @param string $subtype_id
	 */
	function get_subtype_from_id($subtype_id)
	{
		global $CONFIG;
		
		$subtype_id = (int)$subtype_id;
		
		$result = get_data_row("SELECT * from {$CONFIG->dbprefix}entity_subtypes where id=$subtype_id");
		if ($result)
			return $result->subtype;
		
		return false;
	}
	
	/**
	 * This function tests to see if a subtype has a registered class handler.
	 * 
	 * @param string $type The type
	 * @param string $subtype The subtype
	 * @return a class name or null
	 */
	function get_subtype_class($type, $subtype)
	{
		global $CONFIG;
		
		$type = sanitise_string($type);
		$subtype = sanitise_string($subtype);
		
		$result = get_data_row("SELECT * from {$CONFIG->dbprefix}entity_subtypes where type='$type' and subtype='$subtype'");
		if ($result)
			return $result->class;
		
		return NULL;
	}
	
	/**
	 * This function will register a new subtype, returning its ID as required.
	 * 
	 * @param string $type The type you're subtyping
	 * @param string $subtype The subtype label
	 * @param string $class Optional class handler (if you don't want it handled by the generic elgg handler for the type)
	 */
	function add_subtype($type, $subtype, $class = "")
	{
		global $CONFIG;
		
		$type = sanitise_string($type);
		$subtype = sanitise_string($subtype);
		$class = sanitise_string($class);
		
		$id = get_subtype_id($type, $subtype);
		
		if (!$id)
			return insert_data("insert into {$CONFIG->dbprefix}entity_subtypes (type, subtype, class) values ('$type','$subtype','$class')");
		
		return $id;
	}
	
	/**
	 * Update an existing entity.
	 *
	 * @param int $guid
	 * @param int $owner_guid
	 * @param int $access_id
	 */
	function update_entity($guid, $owner_guid,  $access_id)
	{
		global $CONFIG;
		
		$guid = (int)$guid;
		$owner_guid = (int)$owner_guid;
		$access_id = (int)$access_id;
		$time = time();
		
		$access = get_access_list();
		
		
		return update_data("UPDATE {$CONFIG->dbprefix}entities set owner_guid='$owner_guid', access_id='$access_id', time_updated='$time' WHERE guid=$guid and (access_id in {$access} or (access_id = 0 and owner_guid = {$_SESSION['id']}))");
	}
	
	/**
	 * Create a new entity of a given type.
	 * 
	 * @param string $type
	 * @param string $subtype
	 * @param int $owner_guid
	 * @param int $access_id
	 * @return mixed The new entity's GUID or false.
	 */
	function create_entity($type, $subtype, $owner_guid, $access_id)
	{
		global $CONFIG;
	
		$type = sanitise_string($type);
		$subtype = add_subtype($subtype);
		$owner_guid = (int)$owner_guid; 
		$access_id = (int)$access_id;
		$time = time();
					
		if ($type=="") throw new InvalidParameterException("Entity type must be set.");
		if ($owner_guid==0) throw new InvalidParameterException("owner_guid must not be 0");
		
		return insert_data("INSERT into {$CONFIG->dbprefix}entities (type, subtype, owner_guid, access_id, time_created, time_updated) values ('$type',$subtype, $owner_guid, $access_id, $time, $time)");
	}
	
	/**
	 * Retrieve the entity details for a specific GUID, returning it as a stdClass db row.
	 * 
	 * You will only get an object if a) it exists, b) you have access to it.
	 *
	 * @param int $guid
	 */
	function get_entity_as_row($guid)
	{
		global $CONFIG;
		
		$guid = (int)$guid;
		
		$access = get_access_list();
		
		return get_data_row("SELECT * from {$CONFIG->dbprefix}entities where guid=$guid and (access_id in {$access} or (access_id = 0 and owner_guid = {$_SESSION['id']}))");
	}
	
	/**
	 * Create an Elgg* object from a given entity row. 
	 */
	function entity_row_to_elggstar($row)
	{
		if (!($row instanceof stdClass))
			return $row;
			
		// See if there are any registered subtype handler classes for this type and subtype
		$classname = get_subtype_class($row->type, $row->subtype);
		if ($classname!="")
		{
			$tmp = $classname($row);
			
			if (!($tmp instanceof ElggEntity))
				throw new ClassException("$classname is not an ElggEntity.");
				
		}
		else
		{
			switch ($row->type)
			{
				case 'object' : 
					return new ElggObject($row);
				case 'user' : 
					return new ElggUser($row);
				case 'collection' : 
					return new ElggCollection($row); 
				case 'site' : 
					return new ElggSite($row); 
				default: default : throw new InstallationException("Type {$row->type} is not supported. This indicates an error in your installation, most likely caused by an incomplete upgrade.");
			}
		}
		
		return false;
	}
	
	/**
	 * Return the entity for a given guid as the correct object.
	 * @param $guid
	 * @return a child of ElggEntity appropriate for the type.
	 */
	function get_entity($guid)
	{
		return entity_row_to_elggstar(get_entity_as_row($guid));
	}
	
	/**
	 * Return entities matching a given query.
	 * 
	 * @param string $type
	 * @param string $subtype
	 * @param int $owner_guid
	 * @param string $order_by
	 * @param int $limit
	 * @param int $offset
	 */
	function get_entities($type = "", $subtype = "", $owner_guid = 0, $order_by = "time_created desc", $limit = 10, $offset = 0)
	{
		global $CONFIG;
		
		$type = sanitise_string($type);
		$subtype = get_subtype_id($type, $subtype);
		$owner_guid = (int)$owner_guid;
		$order_by = sanitise_string($order_by);
		$limit = (int)$limit;
		$offset = (int)$offset;
		
		$access = get_access_list();
		
		$where = array();
		
		if ($type != "")
			$where[] = "type='$type'";
		if ($subtype)
			$where[] = "subtype=$subtype";
		if ($owner_guid != "")
			$where[] = "owner_guid='$owner_guid'";
		
		$query = "SELECT * from {$CONFIG->dbprefix}entities where ";
		foreach ($where as $w)
			$query .= " $w and ";
		$query .= " (access_id in {$access} or (access_id = 0 and owner_guid = {$_SESSION['id']}))"; // Add access controls
		$query .= " order by $order_by limit $limit, $offset"; // Add order and limit
		
		return get_data($query, "entity_row_to_elggstar");
	}
	
	/**
	 * Return entities matching a given query joining against a relationship.
	 * 
	 * @param string $relationship The relationship eg "friends_of"
	 * @param int $relationship_guid The guid of the entity to use query
	 * @param bool $inverse_relationship Reverse the normal function of the query to instead say "give me all entities for whome $relationship_guid is a $relationship of"
	 * @param string $type 
	 * @param string $subtype
	 * @param int $owner_guid
	 * @param string $order_by
	 * @param int $limit
	 * @param int $offset
	 */
	function get_entities_from_relationship($relationship, $relationship_guid, $inverse_relationship = false, $type = "", $subtype = "", $owner_guid = 0, $order_by = "time_created desc", $limit = 10, $offset = 0)
	{
		global $CONFIG;
		
		$relationship = sanitise_string($relationship);
		$relationship_guid = (int)$relationship_guid;
		$inverse_relationship = (bool)$inverse_relationship;
		$type = sanitise_string($type);
		$subtype = get_subtype_id($type, $subtype);
		$owner_guid = (int)$owner_guid;
		$order_by = sanitise_string($order_by);
		$limit = (int)$limit;
		$offset = (int)$offset;
		
		$access = get_access_list();
		
		$where = array();
		
		if ($relationship!="")
			$where[] = "r.relationship='$relationship'";
		if ($relationship_guid)
			$where[] = ($inverse_relationship ? "r.guid_one='$relationship'" : "r.guid_two='$relationship'");
		if ($type != "")
			$where[] = "e.type='$type'";
		if ($subtype)
			$where[] = "e.subtype=$subtype";
		if ($owner_guid != "")
			$where[] = "e.owner_guid='$owner_guid'";
		
		// Select what we're joining based on the options
		$joinon = "r.guid_two=e.guid";
		if (!$inverse_relationship)
			$joinon = "r.guid_one=e.guid";	
			
		$query = "SELECT * from {$CONFIG->dbprefix}entities e JOIN {$CONFIG->dbprefix}entity_relationships r on $joinon where ";
		foreach ($where as $w)
			$query .= " $w and ";
		$query .= " (e.access_id in {$access} or (e.access_id = 0 and e.owner_guid = {$_SESSION['id']}))"; // Add access controls
		$query .= " order by $order_by limit $limit, $offset"; // Add order and limit
		
		return get_data($query, "entity_row_to_elggstar");
	}
	
	/**
	 * Delete a given entity.
	 * 
	 * @param int $guid
	 */
	function delete_entity($guid)
	{
		global $CONFIG;
		
		// TODO Make sure this deletes all metadata/annotations/relationships/etc!!
		
		$guid = (int)$guid;
		
		$access = get_access_list();
		
		return delete_data("DELETE from {$CONFIG->dbprefix}entities where where guid=$guid and (access_id in {$access} or (access_id = 0 and owner_guid = {$_SESSION['id']}))"); 
		
	}

	/**
	 * Define an arbitrary relationship between two entities.
	 * This relationship could be a friendship, a group membership or a site membership.
	 * 
	 * This function lets you make the statement "$guid_one has $relationship with $guid_two".
	 * 
	 * TODO: Access controls? Are they necessary - I don't think so since we are defining 
	 * relationships between and anyone can do that. The objects should patch some access 
	 * controls over the top tho.
	 * 
	 * @param int $guid_one
	 * @param string $relationship 
	 * @param int $guid_two
	 */
	function add_entity_relationship($guid_one, $relationship, $guid_two)
	{
		global $CONFIG;
		
		$guid_one = (int)$guid_one;
		$relationship = sanitise_string($relationship);
		$guid_two = (int)$guid_two;
			
		return insert_data("INSERT into {$CONFIG->dbprefix}entity_relationships (guid_one, relationship, guid_two) values ($guid_one, 'relationship', $guid_two)");
	}
	
	/**
	 * Determine whether or not a relationship between two entities exists
	 *
	 * @param int $guid_one The GUID of the entity "owning" the relationship
	 * @param string $relationship The type of relationship
	 * @param int $guid_two The GUID of the entity the relationship is with
	 * @return true|false
	 */
	function check_entity_relationship($guid_one, $relationship, $guid_two)
	{
		global $CONFIG;
		
		$guid_one = (int)$guid_one;
		$relationship = sanitise_string($relationship);
		$guid_two = (int)$guid_two;
			
		if ($row = get_data_row("select guid_one from {$CONFIG->dbprefix}entity_relationships where guid_one=$guid_one and relationship='$relationship' and guid_two=$guid_two limit 1")) {
			return true;
		}
		return false;
	}

	/**
	 * Remove an arbitrary relationship between two entities.
	 * 
	 * @param int $guid_one
	 * @param string $relationship 
	 * @param int $guid_two
	 */
	function remove_entity_relationship($guid_one, $relationship, $guid_two)
	{
		global $CONFIG;
		
		$guid_one = (int)$guid_one;
		$relationship = sanitise_string($relationship);
		$guid_two = (int)$guid_two;
			
		return delete_data("DELETE from {$CONFIG->dbprefix}entity_relationships where guid_one=$guid_one and relationship='$relationship' and guid_two=$guid_two");
	}

	/**
	 * Handler called by trigger_plugin_hook on the "export" event.
	 */
	function export_entity_plugin_hook($hook, $entity_type, $returnvalue, $params)
	{
		// Sanity check values
		if ((!is_array($params)) && (!isset($params['guid'])))
			throw new InvalidParameterException("GUID has not been specified during export, this should never happen.");
			
		if (!is_array($returnvalue))
			throw new InvalidParameterException("Entity serialisation function passed a non-array returnvalue parameter");
			
		$guid = (int)$params['guid'];
		
		// Get the entity
		$entity = get_entity($guid);
		
		if ($entity instanceof ElggEntity)
			$returnvalue[] = $entity; // Add object to list of things to serialise - actual serialisation done later

		return $returnvalue;
	}
	
	/** Register the hook, ensuring entities are serialised first */
	register_plugin_hook("export", "all", "export_entity_plugin_hook", 0);
	
?>