1<?php
2/**
3 * REST API: WP_REST_Meta_Fields class
4 *
5 * @package WordPress
6 * @subpackage REST_API
7 * @since 4.7.0
8 */
9
10/**
11 * Core class to manage meta values for an object via the REST API.
12 *
13 * @since 4.7.0
14 */
15#[AllowDynamicProperties]
16abstract class WP_REST_Meta_Fields {
17
18 /**
19 * Retrieves the object meta type.
20 *
21 * @since 4.7.0
22 *
23 * @return string One of 'post', 'comment', 'term', 'user', or anything
24 * else supported by `_get_meta_table()`.
25 */
26 abstract protected function get_meta_type();
27
28 /**
29 * Retrieves the object meta subtype.
30 *
31 * @since 4.9.8
32 *
33 * @return string Subtype for the meta type, or empty string if no specific subtype.
34 */
35 protected function get_meta_subtype() {
36 return '';
37 }
38
39 /**
40 * Retrieves the object type for register_rest_field().
41 *
42 * @since 4.7.0
43 *
44 * @return string The REST field type, such as post type name, taxonomy name, 'comment', or `user`.
45 */
46 abstract protected function get_rest_field_type();
47
48 /**
49 * Registers the meta field.
50 *
51 * @since 4.7.0
52 * @deprecated 5.6.0
53 *
54 * @see register_rest_field()
55 */
56 public function register_field() {
57 _deprecated_function( __METHOD__, '5.6.0' );
58
59 register_rest_field(
60 $this->get_rest_field_type(),
61 'meta',
62 array(
63 'get_callback' => array( $this, 'get_value' ),
64 'update_callback' => array( $this, 'update_value' ),
65 'schema' => $this->get_field_schema(),
66 )
67 );
68 }
69
70 /**
71 * Retrieves the meta field value.
72 *
73 * @since 4.7.0
74 *
75 * @param int $object_id Object ID to fetch meta for.
76 * @param WP_REST_Request $request Full details about the request.
77 * @return array Array containing the meta values keyed by name.
78 */
79 public function get_value( $object_id, $request ) {
80 $fields = $this->get_registered_fields();
81 $response = array();
82
83 foreach ( $fields as $meta_key => $args ) {
84 $name = $args['name'];
85 $all_values = get_metadata( $this->get_meta_type(), $object_id, $meta_key, false );
86
87 if ( $args['single'] ) {
88 if ( empty( $all_values ) ) {
89 $value = $args['schema']['default'];
90 } else {
91 $value = $all_values[0];
92 }
93
94 $value = $this->prepare_value_for_response( $value, $request, $args );
95 } else {
96 $value = array();
97
98 if ( is_array( $all_values ) ) {
99 foreach ( $all_values as $row ) {
100 $value[] = $this->prepare_value_for_response( $row, $request, $args );
101 }
102 }
103 }
104
105 $response[ $name ] = $value;
106 }
107
108 return $response;
109 }
110
111 /**
112 * Prepares a meta value for a response.
113 *
114 * This is required because some native types cannot be stored correctly
115 * in the database, such as booleans. We need to cast back to the relevant
116 * type before passing back to JSON.
117 *
118 * @since 4.7.0
119 *
120 * @param mixed $value Meta value to prepare.
121 * @param WP_REST_Request $request Current request object.
122 * @param array $args Options for the field.
123 * @return mixed Prepared value.
124 */
125 protected function prepare_value_for_response( $value, $request, $args ) {
126 if ( ! empty( $args['prepare_callback'] ) ) {
127 $value = call_user_func( $args['prepare_callback'], $value, $request, $args );
128 }
129
130 return $value;
131 }
132
133 /**
134 * Updates meta values.
135 *
136 * @since 4.7.0
137 *
138 * @param array $meta Array of meta parsed from the request.
139 * @param int $object_id Object ID to fetch meta for.
140 * @return null|WP_Error Null on success, WP_Error object on failure.
141 */
142 public function update_value( $meta, $object_id ) {
143 $fields = $this->get_registered_fields();
144 $error = new WP_Error();
145
146 foreach ( $fields as $meta_key => $args ) {
147 $name = $args['name'];
148 if ( ! array_key_exists( $name, $meta ) ) {
149 continue;
150 }
151
152 $value = $meta[ $name ];
153
154 /*
155 * A null value means reset the field, which is essentially deleting it
156 * from the database and then relying on the default value.
157 *
158 * Non-single meta can also be removed by passing an empty array.
159 */
160 if ( is_null( $value ) || ( array() === $value && ! $args['single'] ) ) {
161 $args = $this->get_registered_fields()[ $meta_key ];
162
163 if ( $args['single'] ) {
164 $current = get_metadata( $this->get_meta_type(), $object_id, $meta_key, true );
165
166 if ( is_wp_error( rest_validate_value_from_schema( $current, $args['schema'] ) ) ) {
167 $error->add(
168 'rest_invalid_stored_value',
169 /* translators: %s: Custom field key. */
170 sprintf( __( 'The %s property has an invalid stored value, and cannot be updated to null.' ), $name ),
171 array( 'status' => 500 )
172 );
173 continue;
174 }
175 }
176
177 $result = $this->delete_meta_value( $object_id, $meta_key, $name );
178 if ( is_wp_error( $result ) ) {
179 $error->merge_from( $result );
180 }
181 continue;
182 }
183
184 if ( ! $args['single'] && is_array( $value ) && count( array_filter( $value, 'is_null' ) ) ) {
185 $error->add(
186 'rest_invalid_stored_value',
187 /* translators: %s: Custom field key. */
188 sprintf( __( 'The %s property has an invalid stored value, and cannot be updated to null.' ), $name ),
189 array( 'status' => 500 )
190 );
191 continue;
192 }
193
194 $is_valid = rest_validate_value_from_schema( $value, $args['schema'], 'meta.' . $name );
195 if ( is_wp_error( $is_valid ) ) {
196 $is_valid->add_data( array( 'status' => 400 ) );
197 $error->merge_from( $is_valid );
198 continue;
199 }
200
201 $value = rest_sanitize_value_from_schema( $value, $args['schema'] );
202
203 if ( $args['single'] ) {
204 $result = $this->update_meta_value( $object_id, $meta_key, $name, $value );
205 } else {
206 $result = $this->update_multi_meta_value( $object_id, $meta_key, $name, $value );
207 }
208
209 if ( is_wp_error( $result ) ) {
210 $error->merge_from( $result );
211 continue;
212 }
213 }
214
215 if ( $error->has_errors() ) {
216 return $error;
217 }
218
219 return null;
220 }
221
222 /**
223 * Deletes a meta value for an object.
224 *
225 * @since 4.7.0
226 *
227 * @param int $object_id Object ID the field belongs to.
228 * @param string $meta_key Key for the field.
229 * @param string $name Name for the field that is exposed in the REST API.
230 * @return true|WP_Error True if meta field is deleted, WP_Error otherwise.
231 */
232 protected function delete_meta_value( $object_id, $meta_key, $name ) {
233 $meta_type = $this->get_meta_type();
234
235 if ( ! current_user_can( "delete_{$meta_type}_meta", $object_id, $meta_key ) ) {
236 return new WP_Error(
237 'rest_cannot_delete',
238 /* translators: %s: Custom field key. */
239 sprintf( __( 'Sorry, you are not allowed to edit the %s custom field.' ), $name ),
240 array(
241 'key' => $name,
242 'status' => rest_authorization_required_code(),
243 )
244 );
245 }
246
247 if ( null === get_metadata_raw( $meta_type, $object_id, wp_slash( $meta_key ) ) ) {
248 return true;
249 }
250
251 if ( ! delete_metadata( $meta_type, $object_id, wp_slash( $meta_key ) ) ) {
252 return new WP_Error(
253 'rest_meta_database_error',
254 __( 'Could not delete meta value from database.' ),
255 array(
256 'key' => $name,
257 'status' => WP_Http::INTERNAL_SERVER_ERROR,
258 )
259 );
260 }
261
262 return true;
263 }
264
265 /**
266 * Updates multiple meta values for an object.
267 *
268 * Alters the list of values in the database to match the list of provided values.
269 *
270 * @since 4.7.0
271 * @since 6.7.0 Stores values into DB even if provided registered default value.
272 *
273 * @param int $object_id Object ID to update.
274 * @param string $meta_key Key for the custom field.
275 * @param string $name Name for the field that is exposed in the REST API.
276 * @param array $values List of values to update to.
277 * @return true|WP_Error True if meta fields are updated, WP_Error otherwise.
278 */
279 protected function update_multi_meta_value( $object_id, $meta_key, $name, $values ) {
280 $meta_type = $this->get_meta_type();
281
282 if ( ! current_user_can( "edit_{$meta_type}_meta", $object_id, $meta_key ) ) {
283 return new WP_Error(
284 'rest_cannot_update',
285 /* translators: %s: Custom field key. */
286 sprintf( __( 'Sorry, you are not allowed to edit the %s custom field.' ), $name ),
287 array(
288 'key' => $name,
289 'status' => rest_authorization_required_code(),
290 )
291 );
292 }
293
294 $current_values = get_metadata_raw( $meta_type, $object_id, $meta_key, false );
295 $subtype = get_object_subtype( $meta_type, $object_id );
296
297 if ( ! is_array( $current_values ) ) {
298 $current_values = array();
299 }
300
301 $to_remove = $current_values;
302 $to_add = $values;
303
304 foreach ( $to_add as $add_key => $value ) {
305 $remove_keys = array_keys(
306 array_filter(
307 $current_values,
308 function ( $stored_value ) use ( $meta_key, $subtype, $value ) {
309 return $this->is_meta_value_same_as_stored_value( $meta_key, $subtype, $stored_value, $value );
310 }
311 )
312 );
313
314 if ( empty( $remove_keys ) ) {
315 continue;
316 }
317
318 if ( count( $remove_keys ) > 1 ) {
319 // To remove, we need to remove first, then add, so don't touch.
320 continue;
321 }
322
323 $remove_key = $remove_keys[0];
324
325 unset( $to_remove[ $remove_key ] );
326 unset( $to_add[ $add_key ] );
327 }
328
329 /*
330 * `delete_metadata` removes _all_ instances of the value, so only call once. Otherwise,
331 * `delete_metadata` will return false for subsequent calls of the same value.
332 * Use serialization to produce a predictable string that can be used by array_unique.
333 */
334 $to_remove = array_map( 'maybe_unserialize', array_unique( array_map( 'maybe_serialize', $to_remove ) ) );
335
336 foreach ( $to_remove as $value ) {
337 if ( ! delete_metadata( $meta_type, $object_id, wp_slash( $meta_key ), wp_slash( $value ) ) ) {
338 return new WP_Error(
339 'rest_meta_database_error',
340 /* translators: %s: Custom field key. */
341 sprintf( __( 'Could not update the meta value of %s in database.' ), $meta_key ),
342 array(
343 'key' => $name,
344 'status' => WP_Http::INTERNAL_SERVER_ERROR,
345 )
346 );
347 }
348 }
349
350 foreach ( $to_add as $value ) {
351 if ( ! add_metadata( $meta_type, $object_id, wp_slash( $meta_key ), wp_slash( $value ) ) ) {
352 return new WP_Error(
353 'rest_meta_database_error',
354 /* translators: %s: Custom field key. */
355 sprintf( __( 'Could not update the meta value of %s in database.' ), $meta_key ),
356 array(
357 'key' => $name,
358 'status' => WP_Http::INTERNAL_SERVER_ERROR,
359 )
360 );
361 }
362 }
363
364 return true;
365 }
366
367 /**
368 * Updates a meta value for an object.
369 *
370 * @since 4.7.0
371 * @since 6.7.0 Stores values into DB even if provided registered default value.
372 *
373 * @param int $object_id Object ID to update.
374 * @param string $meta_key Key for the custom field.
375 * @param string $name Name for the field that is exposed in the REST API.
376 * @param mixed $value Updated value.
377 * @return true|WP_Error True if the meta field was updated, WP_Error otherwise.
378 */
379 protected function update_meta_value( $object_id, $meta_key, $name, $value ) {
380 $meta_type = $this->get_meta_type();
381
382 // Do the exact same check for a duplicate value as in update_metadata() to avoid update_metadata() returning false.
383 $old_value = get_metadata_raw( $meta_type, $object_id, $meta_key );
384 $subtype = get_object_subtype( $meta_type, $object_id );
385
386 if ( is_array( $old_value ) && 1 === count( $old_value )
387 && $this->is_meta_value_same_as_stored_value( $meta_key, $subtype, $old_value[0], $value )
388 ) {
389 return true;
390 }
391
392 if ( ! current_user_can( "edit_{$meta_type}_meta", $object_id, $meta_key ) ) {
393 return new WP_Error(
394 'rest_cannot_update',
395 /* translators: %s: Custom field key. */
396 sprintf( __( 'Sorry, you are not allowed to edit the %s custom field.' ), $name ),
397 array(
398 'key' => $name,
399 'status' => rest_authorization_required_code(),
400 )
401 );
402 }
403
404 if ( ! update_metadata( $meta_type, $object_id, wp_slash( $meta_key ), wp_slash( $value ) ) ) {
405 return new WP_Error(
406 'rest_meta_database_error',
407 /* translators: %s: Custom field key. */
408 sprintf( __( 'Could not update the meta value of %s in database.' ), $meta_key ),
409 array(
410 'key' => $name,
411 'status' => WP_Http::INTERNAL_SERVER_ERROR,
412 )
413 );
414 }
415
416 return true;
417 }
418
419 /**
420 * Checks if the user provided value is equivalent to a stored value for the given meta key.
421 *
422 * @since 5.5.0
423 *
424 * @param string $meta_key The meta key being checked.
425 * @param string $subtype The object subtype.
426 * @param mixed $stored_value The currently stored value retrieved from get_metadata().
427 * @param mixed $user_value The value provided by the user.
428 * @return bool
429 */
430 protected function is_meta_value_same_as_stored_value( $meta_key, $subtype, $stored_value, $user_value ) {
431 $args = $this->get_registered_fields()[ $meta_key ];
432 $sanitized = sanitize_meta( $meta_key, $user_value, $this->get_meta_type(), $subtype );
433
434 if ( in_array( $args['type'], array( 'string', 'number', 'integer', 'boolean' ), true ) ) {
435 // The return value of get_metadata will always be a string for scalar types.
436 $sanitized = (string) $sanitized;
437 }
438
439 return $sanitized === $stored_value;
440 }
441
442 /**
443 * Retrieves all the registered meta fields.
444 *
445 * @since 4.7.0
446 *
447 * @return array Registered fields.
448 */
449 protected function get_registered_fields() {
450 $registered = array();
451
452 $meta_type = $this->get_meta_type();
453 $meta_subtype = $this->get_meta_subtype();
454
455 $meta_keys = get_registered_meta_keys( $meta_type );
456 if ( ! empty( $meta_subtype ) ) {
457 $meta_keys = array_merge( $meta_keys, get_registered_meta_keys( $meta_type, $meta_subtype ) );
458 }
459
460 foreach ( $meta_keys as $name => $args ) {
461 if ( empty( $args['show_in_rest'] ) ) {
462 continue;
463 }
464
465 $rest_args = array();
466
467 if ( is_array( $args['show_in_rest'] ) ) {
468 $rest_args = $args['show_in_rest'];
469 }
470
471 $default_args = array(
472 'name' => $name,
473 'single' => $args['single'],
474 'type' => ! empty( $args['type'] ) ? $args['type'] : null,
475 'schema' => array(),
476 'prepare_callback' => array( $this, 'prepare_value' ),
477 );
478
479 $default_schema = array(
480 'type' => $default_args['type'],
481 'title' => empty( $args['label'] ) ? '' : $args['label'],
482 'description' => empty( $args['description'] ) ? '' : $args['description'],
483 'default' => isset( $args['default'] ) ? $args['default'] : null,
484 );
485
486 $rest_args = array_merge( $default_args, $rest_args );
487 $rest_args['schema'] = array_merge( $default_schema, $rest_args['schema'] );
488
489 $type = ! empty( $rest_args['type'] ) ? $rest_args['type'] : null;
490 $type = ! empty( $rest_args['schema']['type'] ) ? $rest_args['schema']['type'] : $type;
491
492 if ( null === $rest_args['schema']['default'] ) {
493 $rest_args['schema']['default'] = static::get_empty_value_for_type( $type );
494 }
495
496 $rest_args['schema'] = rest_default_additional_properties_to_false( $rest_args['schema'] );
497
498 if ( ! in_array( $type, array( 'string', 'boolean', 'integer', 'number', 'array', 'object' ), true ) ) {
499 continue;
500 }
501
502 if ( empty( $rest_args['single'] ) ) {
503 $rest_args['schema'] = array(
504 'type' => 'array',
505 'items' => $rest_args['schema'],
506 );
507 }
508
509 $registered[ $name ] = $rest_args;
510 }
511
512 return $registered;
513 }
514
515 /**
516 * Retrieves the object's meta schema, conforming to JSON Schema.
517 *
518 * @since 4.7.0
519 *
520 * @return array Field schema data.
521 */
522 public function get_field_schema() {
523 $fields = $this->get_registered_fields();
524
525 $schema = array(
526 'description' => __( 'Meta fields.' ),
527 'type' => 'object',
528 'context' => array( 'view', 'edit' ),
529 'properties' => array(),
530 'arg_options' => array(
531 'sanitize_callback' => null,
532 'validate_callback' => array( $this, 'check_meta_is_array' ),
533 ),
534 );
535
536 foreach ( $fields as $args ) {
537 $schema['properties'][ $args['name'] ] = $args['schema'];
538 }
539
540 return $schema;
541 }
542
543 /**
544 * Prepares a meta value for output.
545 *
546 * Default preparation for meta fields. Override by passing the
547 * `prepare_callback` in your `show_in_rest` options.
548 *
549 * @since 4.7.0
550 *
551 * @param mixed $value Meta value from the database.
552 * @param WP_REST_Request $request Request object.
553 * @param array $args REST-specific options for the meta key.
554 * @return mixed Value prepared for output. If a non-JsonSerializable object, null.
555 */
556 public static function prepare_value( $value, $request, $args ) {
557 if ( $args['single'] ) {
558 $schema = $args['schema'];
559 } else {
560 $schema = $args['schema']['items'];
561 }
562
563 if ( '' === $value && in_array( $schema['type'], array( 'boolean', 'integer', 'number' ), true ) ) {
564 $value = static::get_empty_value_for_type( $schema['type'] );
565 }
566
567 if ( is_wp_error( rest_validate_value_from_schema( $value, $schema ) ) ) {
568 return null;
569 }
570
571 return rest_sanitize_value_from_schema( $value, $schema );
572 }
573
574 /**
575 * Check the 'meta' value of a request is an associative array.
576 *
577 * @since 4.7.0
578 *
579 * @param mixed $value The meta value submitted in the request.
580 * @param WP_REST_Request $request Full details about the request.
581 * @param string $param The parameter name.
582 * @return array|false The meta array, if valid, false otherwise.
583 */
584 public function check_meta_is_array( $value, $request, $param ) {
585 if ( ! is_array( $value ) ) {
586 return false;
587 }
588
589 return $value;
590 }
591
592 /**
593 * Recursively add additionalProperties = false to all objects in a schema if no additionalProperties setting
594 * is specified.
595 *
596 * This is needed to restrict properties of objects in meta values to only
597 * registered items, as the REST API will allow additional properties by
598 * default.
599 *
600 * @since 5.3.0
601 * @deprecated 5.6.0 Use rest_default_additional_properties_to_false() instead.
602 *
603 * @param array $schema The schema array.
604 * @return array
605 */
606 protected function default_additional_properties_to_false( $schema ) {
607 _deprecated_function( __METHOD__, '5.6.0', 'rest_default_additional_properties_to_false()' );
608
609 return rest_default_additional_properties_to_false( $schema );
610 }
611
612 /**
613 * Gets the empty value for a schema type.
614 *
615 * @since 5.3.0
616 *
617 * @param string $type The schema type.
618 * @return mixed
619 */
620 protected static function get_empty_value_for_type( $type ) {
621 switch ( $type ) {
622 case 'string':
623 return '';
624 case 'boolean':
625 return false;
626 case 'integer':
627 return 0;
628 case 'number':
629 return 0.0;
630 case 'array':
631 case 'object':
632 return array();
633 default:
634 return null;
635 }
636 }
637}
638