1<?php
  2/**
  3 * Dependencies API: WP_Dependencies base class
  4 *
  5 * @since 2.6.0
  6 *
  7 * @package WordPress
  8 * @subpackage Dependencies
  9 */
 10
 11/**
 12 * Core base class extended to register items.
 13 *
 14 * @since 2.6.0
 15 *
 16 * @see _WP_Dependency
 17 */
 18#[AllowDynamicProperties]
 19class WP_Dependencies {
 20	/**
 21	 * An array of all registered dependencies keyed by handle.
 22	 *
 23	 * @since 2.6.8
 24	 *
 25	 * @var _WP_Dependency[]
 26	 */
 27	public $registered = array();
 28
 29	/**
 30	 * An array of handles of queued dependencies.
 31	 *
 32	 * @since 2.6.8
 33	 *
 34	 * @var string[]
 35	 */
 36	public $queue = array();
 37
 38	/**
 39	 * An array of handles of dependencies to queue.
 40	 *
 41	 * @since 2.6.0
 42	 *
 43	 * @var string[]
 44	 */
 45	public $to_do = array();
 46
 47	/**
 48	 * An array of handles of dependencies already queued.
 49	 *
 50	 * @since 2.6.0
 51	 *
 52	 * @var string[]
 53	 */
 54	public $done = array();
 55
 56	/**
 57	 * An array of additional arguments passed when a handle is registered.
 58	 *
 59	 * Arguments are appended to the item query string.
 60	 *
 61	 * @since 2.6.0
 62	 *
 63	 * @var array
 64	 */
 65	public $args = array();
 66
 67	/**
 68	 * An array of dependency groups to enqueue.
 69	 *
 70	 * Each entry is keyed by handle and represents the integer group level or boolean
 71	 * false if the handle has no group.
 72	 *
 73	 * @since 2.8.0
 74	 *
 75	 * @var (int|false)[]
 76	 */
 77	public $groups = array();
 78
 79	/**
 80	 * A handle group to enqueue.
 81	 *
 82	 * @since 2.8.0
 83	 *
 84	 * @deprecated 4.5.0
 85	 * @var int
 86	 */
 87	public $group = 0;
 88
 89	/**
 90	 * Cached lookup array of flattened queued items and dependencies.
 91	 *
 92	 * @since 5.4.0
 93	 *
 94	 * @var array
 95	 */
 96	private $all_queued_deps;
 97
 98	/**
 99	 * List of assets enqueued before details were registered.
100	 *
101	 * @since 5.9.0
102	 *
103	 * @var array
104	 */
105	private $queued_before_register = array();
106
107	/**
108	 * List of handles for dependencies encountered which themselves have missing dependencies.
109	 *
110	 * A dependency handle is added to this list when it is discovered to have missing dependencies. At this time, a
111	 * warning is emitted with {@see _doing_it_wrong()}. The handle is then added to this list, so that duplicate
112	 * warnings don't occur.
113	 *
114	 * @since 6.9.1
115	 * @var string[]
116	 */
117	private $dependencies_with_missing_dependencies = array();
118
119	/**
120	 * Processes the items and dependencies.
121	 *
122	 * Processes the items passed to it or the queue, and their dependencies.
123	 *
124	 * @since 2.6.0
125	 * @since 2.8.0 Added the `$group` parameter.
126	 *
127	 * @param string|string[]|false $handles Optional. Items to be processed: queue (false),
128	 *                                       single item (string), or multiple items (array of strings).
129	 *                                       Default false.
130	 * @param int|false             $group   Optional. Group level: level (int), no group (false).
131	 * @return string[] Array of handles of items that have been processed.
132	 */
133	public function do_items( $handles = false, $group = false ) {
134		/*
135		 * If nothing is passed, print the queue. If a string is passed,
136		 * print that item. If an array is passed, print those items.
137		 */
138		$handles = false === $handles ? $this->queue : (array) $handles;
139		$this->all_deps( $handles );
140
141		foreach ( $this->to_do as $key => $handle ) {
142			if ( ! in_array( $handle, $this->done, true ) && isset( $this->registered[ $handle ] ) ) {
143				/*
144				 * Attempt to process the item. If successful,
145				 * add the handle to the done array.
146				 *
147				 * Unset the item from the to_do array.
148				 */
149				if ( $this->do_item( $handle, $group ) ) {
150					$this->done[] = $handle;
151				}
152
153				unset( $this->to_do[ $key ] );
154			}
155		}
156
157		return $this->done;
158	}
159
160	/**
161	 * Processes a dependency.
162	 *
163	 * @since 2.6.0
164	 * @since 5.5.0 Added the `$group` parameter.
165	 *
166	 * @param string    $handle Name of the item. Should be unique.
167	 * @param int|false $group  Optional. Group level: level (int), no group (false).
168	 *                          Default false.
169	 * @return bool True on success, false if not set.
170	 */
171	public function do_item( $handle, $group = false ) {
172		return isset( $this->registered[ $handle ] );
173	}
174
175	/**
176	 * Determines dependencies.
177	 *
178	 * Recursively builds an array of items to process taking
179	 * dependencies into account. Does NOT catch infinite loops.
180	 *
181	 * @since 2.1.0
182	 * @since 2.6.0 Moved from `WP_Scripts`.
183	 * @since 2.8.0 Added the `$group` parameter.
184	 *
185	 * @param string|string[] $handles   Item handle (string) or item handles (array of strings).
186	 * @param bool            $recursion Optional. Internal flag that function is calling itself.
187	 *                                   Default false.
188	 * @param int|false       $group     Optional. Group level: level (int), no group (false).
189	 *                                   Default false.
190	 * @return bool True on success, false on failure.
191	 */
192	public function all_deps( $handles, $recursion = false, $group = false ) {
193		$handles = (array) $handles;
194		if ( ! $handles ) {
195			return false;
196		}
197
198		foreach ( $handles as $handle ) {
199			$handle_parts = explode( '?', $handle );
200			$handle       = $handle_parts[0];
201			$queued       = in_array( $handle, $this->to_do, true );
202
203			if ( in_array( $handle, $this->done, true ) ) { // Already done.
204				continue;
205			}
206
207			$moved     = $this->set_group( $handle, $recursion, $group );
208			$new_group = $this->groups[ $handle ];
209
210			if ( $queued && ! $moved ) { // Already queued and in the right group.
211				continue;
212			}
213
214			$keep_going           = true;
215			$missing_dependencies = array();
216			if ( isset( $this->registered[ $handle ] ) && count( $this->registered[ $handle ]->deps ) > 0 ) {
217				$missing_dependencies = array_diff( $this->registered[ $handle ]->deps, array_keys( $this->registered ) );
218			}
219			if ( ! isset( $this->registered[ $handle ] ) ) {
220				$keep_going = false; // Item doesn't exist.
221			} elseif ( count( $missing_dependencies ) > 0 ) {
222				if ( ! in_array( $handle, $this->dependencies_with_missing_dependencies, true ) ) {
223					_doing_it_wrong(
224						get_class( $this ) . '::add',
225						$this->get_dependency_warning_message( $handle, $missing_dependencies ),
226						'6.9.1'
227					);
228					$this->dependencies_with_missing_dependencies[] = $handle;
229				}
230				$keep_going = false; // Item requires dependencies that don't exist.
231			} elseif ( $this->registered[ $handle ]->deps && ! $this->all_deps( $this->registered[ $handle ]->deps, true, $new_group ) ) {
232				$keep_going = false; // Item requires dependencies that don't exist.
233			}
234
235			if ( ! $keep_going ) { // Either item or its dependencies don't exist.
236				if ( $recursion ) {
237					return false; // Abort this branch.
238				} else {
239					continue; // We're at the top level. Move on to the next one.
240				}
241			}
242
243			if ( $queued ) { // Already grabbed it and its dependencies.
244				continue;
245			}
246
247			if ( isset( $handle_parts[1] ) ) {
248				$this->args[ $handle ] = $handle_parts[1];
249			}
250
251			$this->to_do[] = $handle;
252		}
253
254		return true;
255	}
256
257	/**
258	 * Register an item.
259	 *
260	 * Registers the item if no item of that name already exists.
261	 *
262	 * @since 2.1.0
263	 * @since 2.6.0 Moved from `WP_Scripts`.
264	 *
265	 * @param string           $handle Name of the item. Should be unique.
266	 * @param string|false     $src    Full URL of the item, or path of the item relative
267	 *                                 to the WordPress root directory. If source is set to false,
268	 *                                 the item is an alias of other items it depends on.
269	 * @param string[]         $deps   Optional. An array of registered item handles this item depends on.
270	 *                                 Default empty array.
271	 * @param string|bool|null $ver    Optional. String specifying item version number, if it has one,
272	 *                                 which is added to the URL as a query string for cache busting purposes.
273	 *                                 If version is set to false, a version number is automatically added
274	 *                                 equal to current installed WordPress version.
275	 *                                 If set to null, no version is added.
276	 * @param mixed            $args   Optional. Custom property of the item. NOT the class property $args.
277	 *                                 Examples: $media, $in_footer.
278	 * @return bool Whether the item has been registered. True on success, false on failure.
279	 */
280	public function add( $handle, $src, $deps = array(), $ver = false, $args = null ) {
281		if ( isset( $this->registered[ $handle ] ) ) {
282			return false;
283		}
284		$this->registered[ $handle ] = new _WP_Dependency( $handle, $src, $deps, $ver, $args );
285
286		// If the item was enqueued before the details were registered, enqueue it now.
287		if ( array_key_exists( $handle, $this->queued_before_register ) ) {
288			if ( ! is_null( $this->queued_before_register[ $handle ] ) ) {
289				$this->enqueue( $handle . '?' . $this->queued_before_register[ $handle ] );
290			} else {
291				$this->enqueue( $handle );
292			}
293
294			unset( $this->queued_before_register[ $handle ] );
295		}
296
297		return true;
298	}
299
300	/**
301	 * Add extra item data.
302	 *
303	 * Adds data to a registered item.
304	 *
305	 * @since 2.6.0
306	 *
307	 * @param string $handle Name of the item. Should be unique.
308	 * @param string $key    The data key.
309	 * @param mixed  $value  The data value.
310	 * @return bool True on success, false on failure.
311	 */
312	public function add_data( $handle, $key, $value ) {
313		if ( ! isset( $this->registered[ $handle ] ) ) {
314			return false;
315		}
316		if ( 'conditional' === $key && '_required-conditional-dependency_' !== $value ) {
317			_deprecated_argument(
318				'WP_Dependencies->add_data()',
319				'6.9.0',
320				__( 'IE conditional comments are ignored by all supported browsers.' )
321			);
322		}
323
324		return $this->registered[ $handle ]->add_data( $key, $value );
325	}
326
327	/**
328	 * Get extra item data.
329	 *
330	 * Gets data associated with a registered item.
331	 *
332	 * @since 3.3.0
333	 *
334	 * @param string $handle Name of the item. Should be unique.
335	 * @param string $key    The data key.
336	 * @return mixed Extra item data (string), false otherwise.
337	 */
338	public function get_data( $handle, $key ) {
339		if ( ! isset( $this->registered[ $handle ] ) ) {
340			return false;
341		}
342
343		if ( ! isset( $this->registered[ $handle ]->extra[ $key ] ) ) {
344			return false;
345		}
346
347		return $this->registered[ $handle ]->extra[ $key ];
348	}
349
350	/**
351	 * Un-register an item or items.
352	 *
353	 * @since 2.1.0
354	 * @since 2.6.0 Moved from `WP_Scripts`.
355	 *
356	 * @param string|string[] $handles Item handle (string) or item handles (array of strings).
357	 */
358	public function remove( $handles ) {
359		foreach ( (array) $handles as $handle ) {
360			unset( $this->registered[ $handle ] );
361		}
362	}
363
364	/**
365	 * Queue an item or items.
366	 *
367	 * Decodes handles and arguments, then queues handles and stores
368	 * arguments in the class property $args. For example in extending
369	 * classes, $args is appended to the item url as a query string.
370	 * Note $args is NOT the $args property of items in the $registered array.
371	 *
372	 * @since 2.1.0
373	 * @since 2.6.0 Moved from `WP_Scripts`.
374	 *
375	 * @param string|string[] $handles Item handle (string) or item handles (array of strings).
376	 */
377	public function enqueue( $handles ) {
378		foreach ( (array) $handles as $handle ) {
379			$handle = explode( '?', $handle );
380
381			if ( ! in_array( $handle[0], $this->queue, true ) && isset( $this->registered[ $handle[0] ] ) ) {
382				$this->queue[] = $handle[0];
383
384				// Reset all dependencies so they must be recalculated in recurse_deps().
385				$this->all_queued_deps = null;
386
387				if ( isset( $handle[1] ) ) {
388					$this->args[ $handle[0] ] = $handle[1];
389				}
390			} elseif ( ! isset( $this->registered[ $handle[0] ] ) ) {
391				$this->queued_before_register[ $handle[0] ] = null; // $args
392
393				if ( isset( $handle[1] ) ) {
394					$this->queued_before_register[ $handle[0] ] = $handle[1];
395				}
396			}
397		}
398	}
399
400	/**
401	 * Dequeue an item or items.
402	 *
403	 * Decodes handles and arguments, then dequeues handles
404	 * and removes arguments from the class property $args.
405	 *
406	 * @since 2.1.0
407	 * @since 2.6.0 Moved from `WP_Scripts`.
408	 *
409	 * @param string|string[] $handles Item handle (string) or item handles (array of strings).
410	 */
411	public function dequeue( $handles ) {
412		foreach ( (array) $handles as $handle ) {
413			$handle = explode( '?', $handle );
414			$key    = array_search( $handle[0], $this->queue, true );
415
416			if ( false !== $key ) {
417				// Reset all dependencies so they must be recalculated in recurse_deps().
418				$this->all_queued_deps = null;
419
420				unset( $this->queue[ $key ] );
421				unset( $this->args[ $handle[0] ] );
422			} elseif ( array_key_exists( $handle[0], $this->queued_before_register ) ) {
423				unset( $this->queued_before_register[ $handle[0] ] );
424			}
425		}
426	}
427
428	/**
429	 * Recursively search the passed dependency tree for a handle.
430	 *
431	 * @since 4.0.0
432	 *
433	 * @param string[] $queue  An array of queued _WP_Dependency handles.
434	 * @param string   $handle Name of the item. Should be unique.
435	 * @return bool Whether the handle is found after recursively searching the dependency tree.
436	 */
437	protected function recurse_deps( $queue, $handle ) {
438		if ( isset( $this->all_queued_deps ) ) {
439			return isset( $this->all_queued_deps[ $handle ] );
440		}
441
442		$all_deps = array_fill_keys( $queue, true );
443		$queues   = array();
444		$done     = array();
445
446		while ( $queue ) {
447			foreach ( $queue as $queued ) {
448				if ( ! isset( $done[ $queued ] ) && isset( $this->registered[ $queued ] ) ) {
449					$deps = $this->registered[ $queued ]->deps;
450					if ( $deps ) {
451						$all_deps += array_fill_keys( $deps, true );
452						array_push( $queues, $deps );
453					}
454					$done[ $queued ] = true;
455				}
456			}
457			$queue = array_pop( $queues );
458		}
459
460		$this->all_queued_deps = $all_deps;
461
462		return isset( $this->all_queued_deps[ $handle ] );
463	}
464
465	/**
466	 * Query the list for an item.
467	 *
468	 * @since 2.1.0
469	 * @since 2.6.0 Moved from `WP_Scripts`.
470	 *
471	 * @param string $handle Name of the item. Should be unique.
472	 * @param string $status Optional. Status of the item to query. Default 'registered'.
473	 * @return bool|_WP_Dependency Found, or object Item data.
474	 */
475	public function query( $handle, $status = 'registered' ) {
476		switch ( $status ) {
477			case 'registered':
478			case 'scripts': // Back compat.
479				if ( isset( $this->registered[ $handle ] ) ) {
480					return $this->registered[ $handle ];
481				}
482				return false;
483
484			case 'enqueued':
485			case 'queue': // Back compat.
486				if ( in_array( $handle, $this->queue, true ) ) {
487					return true;
488				}
489				return $this->recurse_deps( $this->queue, $handle );
490
491			case 'to_do':
492			case 'to_print': // Back compat.
493				return in_array( $handle, $this->to_do, true );
494
495			case 'done':
496			case 'printed': // Back compat.
497				return in_array( $handle, $this->done, true );
498		}
499
500		return false;
501	}
502
503	/**
504	 * Set item group, unless already in a lower group.
505	 *
506	 * @since 2.8.0
507	 *
508	 * @param string    $handle    Name of the item. Should be unique.
509	 * @param bool      $recursion Internal flag that calling function was called recursively.
510	 * @param int|false $group     Group level: level (int), no group (false).
511	 * @return bool Not already in the group or a lower group.
512	 */
513	public function set_group( $handle, $recursion, $group ) {
514		$group = (int) $group;
515
516		if ( isset( $this->groups[ $handle ] ) && $this->groups[ $handle ] <= $group ) {
517			return false;
518		}
519
520		$this->groups[ $handle ] = $group;
521
522		return true;
523	}
524
525	/**
526	 * Get etag header for cache validation.
527	 *
528	 * @since 6.7.0
529	 *
530	 * @global string $wp_version The WordPress version string.
531	 *
532	 * @param string[] $load Array of script or style handles to load.
533	 * @return string Etag header.
534	 */
535	public function get_etag( $load ) {
536		/*
537		 * Note: wp_get_wp_version() is not used here, as this file can be included
538		 * via wp-admin/load-scripts.php or wp-admin/load-styles.php, in which case
539		 * wp-includes/functions.php is not loaded.
540		 */
541		global $wp_version;
542
543		$etag = "WP:{$wp_version};";
544
545		foreach ( $load as $handle ) {
546			if ( ! array_key_exists( $handle, $this->registered ) ) {
547				continue;
548			}
549
550			$ver   = $this->registered[ $handle ]->ver ?? $wp_version;
551			$etag .= "{$handle}:{$ver};";
552		}
553
554		/*
555		 * This is not intended to be cryptographically secure, just a fast way to get
556		 * a fixed length string based on the script versions. As this file does not
557		 * load the full WordPress environment, it is not possible to use the salted
558		 * wp_hash() function.
559		 */
560		return 'W/"' . md5( $etag ) . '"';
561	}
562
563	/**
564	 * Gets a dependency warning message for a handle.
565	 *
566	 * @since 6.9.1
567	 *
568	 * @param string   $handle                     Handle with missing dependencies.
569	 * @param string[] $missing_dependency_handles Missing dependency handles.
570	 * @return string Formatted, localized warning message.
571	 */
572	protected function get_dependency_warning_message( $handle, $missing_dependency_handles ) {
573		return sprintf(
574			/* translators: 1: Handle, 2: List of missing dependency handles. */
575			__( 'The handle "%1$s" was enqueued with dependencies that are not registered: %2$s.' ),
576			$handle,
577			implode( wp_get_list_item_separator(), $missing_dependency_handles )
578		);
579	}
580}
581