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 abstract class WP_REST_Meta_Fields {

    16 

    17 	/**

    18 	 * Retrieves the object meta type.

    19 	 *

    20 	 * @since 4.7.0

    21 	 *

    22 	 * @return string One of 'post', 'comment', 'term', 'user', or anything

    23 	 *                else supported by `_get_meta_table()`.

    24 	 */

    25 	abstract protected function get_meta_type();

    26 

    27 	/**

    28 	 * Retrieves the object meta subtype.

    29 	 *

    30 	 * @since 4.9.8

    31 	 *

    32 	 * @return string Subtype for the meta type, or empty string if no specific subtype.

    33 	 */

    34 	protected function get_meta_subtype() {

    35 		return '';

    36 	}

    37 

    38 	/**

    39 	 * Retrieves the object type for register_rest_field().

    40 	 *

    41 	 * @since 4.7.0

    42 	 *

    43 	 * @return string The REST field type, such as post type name, taxonomy name, 'comment', or `user`.

    44 	 */

    45 	abstract protected function get_rest_field_type();

    46 

    47 	/**

    48 	 * Registers the meta field.

    49 	 *

    50 	 * @since 4.7.0

    51 	 *

    52 	 * @see register_rest_field()

    53 	 */

    54 	public function register_field() {

    55 		register_rest_field( $this->get_rest_field_type(), 'meta', array(

    56 			'get_callback'    => array( $this, 'get_value' ),

    57 			'update_callback' => array( $this, 'update_value' ),

    58 			'schema'          => $this->get_field_schema(),

    59 		));

    60 	}

    61 

    62 	/**

    63 	 * Retrieves the meta field value.

    64 	 *

    65 	 * @since 4.7.0

    66 	 *

    67 	 * @param int             $object_id Object ID to fetch meta for.

    68 	 * @param WP_REST_Request $request   Full details about the request.

    69 	 * @return WP_Error|object Object containing the meta values by name, otherwise WP_Error object.

    70 	 */

    71 	public function get_value( $object_id, $request ) {

    72 		$fields   = $this->get_registered_fields();

    73 		$response = array();

    74 

    75 		foreach ( $fields as $meta_key => $args ) {

    76 			$name = $args['name'];

    77 			$all_values = get_metadata( $this->get_meta_type(), $object_id, $meta_key, false );

    78 			if ( $args['single'] ) {

    79 				if ( empty( $all_values ) ) {

    80 					$value = $args['schema']['default'];

    81 				} else {

    82 					$value = $all_values[0];

    83 				}

    84 				$value = $this->prepare_value_for_response( $value, $request, $args );

    85 			} else {

    86 				$value = array();

    87 				foreach ( $all_values as $row ) {

    88 					$value[] = $this->prepare_value_for_response( $row, $request, $args );

    89 				}

    90 			}

    91 

    92 			$response[ $name ] = $value;

    93 		}

    94 

    95 		return $response;

    96 	}

    97 

    98 	/**

    99 	 * Prepares a meta value for a response.

   100 	 *

   101 	 * This is required because some native types cannot be stored correctly

   102 	 * in the database, such as booleans. We need to cast back to the relevant

   103 	 * type before passing back to JSON.

   104 	 *

   105 	 * @since 4.7.0

   106 	 *

   107 	 * @param mixed           $value   Meta value to prepare.

   108 	 * @param WP_REST_Request $request Current request object.

   109 	 * @param array           $args    Options for the field.

   110 	 * @return mixed Prepared value.

   111 	 */

   112 	protected function prepare_value_for_response( $value, $request, $args ) {

   113 		if ( ! empty( $args['prepare_callback'] ) ) {

   114 			$value = call_user_func( $args['prepare_callback'], $value, $request, $args );

   115 		}

   116 

   117 		return $value;

   118 	}

   119 

   120 	/**

   121 	 * Updates meta values.

   122 	 *

   123 	 * @since 4.7.0

   124 	 *

   125 	 * @param array           $meta      Array of meta parsed from the request.

   126 	 * @param int             $object_id Object ID to fetch meta for.

   127 	 * @return WP_Error|null WP_Error if one occurs, null on success.

   128 	 */

   129 	public function update_value( $meta, $object_id ) {

   130 		$fields = $this->get_registered_fields();

   131 		foreach ( $fields as $meta_key => $args ) {

   132 			$name = $args['name'];

   133 			if ( ! array_key_exists( $name, $meta ) ) {

   134 				continue;

   135 			}

   136 

   137 			/*

   138 			 * A null value means reset the field, which is essentially deleting it

   139 			 * from the database and then relying on the default value.

   140 			 */

   141 			if ( is_null( $meta[ $name ] ) ) {

   142 				$result = $this->delete_meta_value( $object_id, $meta_key, $name );

   143 				if ( is_wp_error( $result ) ) {

   144 					return $result;

   145 				}

   146 				continue;

   147 			}

   148 

   149 			$is_valid = rest_validate_value_from_schema( $meta[ $name ], $args['schema'], 'meta.' . $name );

   150 			if ( is_wp_error( $is_valid ) ) {

   151 				$is_valid->add_data( array( 'status' => 400 ) );

   152 				return $is_valid;

   153 			}

   154 

   155 			$value = rest_sanitize_value_from_schema( $meta[ $name ], $args['schema'] );

   156 

   157 			if ( $args['single'] ) {

   158 				$result = $this->update_meta_value( $object_id, $meta_key, $name, $value );

   159 			} else {

   160 				$result = $this->update_multi_meta_value( $object_id, $meta_key, $name, $value );

   161 			}

   162 

   163 			if ( is_wp_error( $result ) ) {

   164 				return $result;

   165 			}

   166 		}

   167 

   168 		return null;

   169 	}

   170 

   171 	/**

   172 	 * Deletes a meta value for an object.

   173 	 *

   174 	 * @since 4.7.0

   175 	 *

   176 	 * @param int    $object_id Object ID the field belongs to.

   177 	 * @param string $meta_key  Key for the field.

   178 	 * @param string $name      Name for the field that is exposed in the REST API.

   179 	 * @return bool|WP_Error True if meta field is deleted, WP_Error otherwise.

   180 	 */

   181 	protected function delete_meta_value( $object_id, $meta_key, $name ) {

   182 		$meta_type = $this->get_meta_type();

   183 		if ( ! current_user_can( "delete_{$meta_type}_meta", $object_id, $meta_key ) ) {

   184 			return new WP_Error(

   185 				'rest_cannot_delete',

   186 				/* translators: %s: custom field key */

   187 				sprintf( __( 'Sorry, you are not allowed to edit the %s custom field.' ), $name ),

   188 				array( 'key' => $name, 'status' => rest_authorization_required_code() )

   189 			);

   190 		}

   191 

   192 		if ( ! delete_metadata( $meta_type, $object_id, wp_slash( $meta_key ) ) ) {

   193 			return new WP_Error(

   194 				'rest_meta_database_error',

   195 				__( 'Could not delete meta value from database.' ),

   196 				array( 'key' => $name, 'status' => WP_Http::INTERNAL_SERVER_ERROR )

   197 			);

   198 		}

   199 

   200 		return true;

   201 	}

   202 

   203 	/**

   204 	 * Updates multiple meta values for an object.

   205 	 *

   206 	 * Alters the list of values in the database to match the list of provided values.

   207 	 *

   208 	 * @since 4.7.0

   209 	 *

   210 	 * @param int    $object_id Object ID to update.

   211 	 * @param string $meta_key  Key for the custom field.

   212 	 * @param string $name      Name for the field that is exposed in the REST API.

   213 	 * @param array  $values    List of values to update to.

   214 	 * @return bool|WP_Error True if meta fields are updated, WP_Error otherwise.

   215 	 */

   216 	protected function update_multi_meta_value( $object_id, $meta_key, $name, $values ) {

   217 		$meta_type = $this->get_meta_type();

   218 		if ( ! current_user_can( "edit_{$meta_type}_meta", $object_id, $meta_key ) ) {

   219 			return new WP_Error(

   220 				'rest_cannot_update',

   221 				/* translators: %s: custom field key */

   222 				sprintf( __( 'Sorry, you are not allowed to edit the %s custom field.' ), $name ),

   223 				array( 'key' => $name, 'status' => rest_authorization_required_code() )

   224 			);

   225 		}

   226 

   227 		$current = get_metadata( $meta_type, $object_id, $meta_key, false );

   228 

   229 		$to_remove = $current;

   230 		$to_add    = $values;

   231 

   232 		foreach ( $to_add as $add_key => $value ) {

   233 			$remove_keys = array_keys( $to_remove, $value, true );

   234 

   235 			if ( empty( $remove_keys ) ) {

   236 				continue;

   237 			}

   238 

   239 			if ( count( $remove_keys ) > 1 ) {

   240 				// To remove, we need to remove first, then add, so don't touch.

   241 				continue;

   242 			}

   243 

   244 			$remove_key = $remove_keys[0];

   245 

   246 			unset( $to_remove[ $remove_key ] );

   247 			unset( $to_add[ $add_key ] );

   248 		}

   249 

   250 		// `delete_metadata` removes _all_ instances of the value, so only call once.

   251 		$to_remove = array_unique( $to_remove );

   252 

   253 		foreach ( $to_remove as $value ) {

   254 			if ( ! delete_metadata( $meta_type, $object_id, wp_slash( $meta_key ), wp_slash( $value ) ) ) {

   255 				return new WP_Error(

   256 					'rest_meta_database_error',

   257 					__( 'Could not update meta value in database.' ),

   258 					array( 'key' => $name, 'status' => WP_Http::INTERNAL_SERVER_ERROR )

   259 				);

   260 			}

   261 		}

   262 

   263 		foreach ( $to_add as $value ) {

   264 			if ( ! add_metadata( $meta_type, $object_id, wp_slash( $meta_key ), wp_slash( $value ) ) ) {

   265 				return new WP_Error(

   266 					'rest_meta_database_error',

   267 					__( 'Could not update meta value in database.' ),

   268 					array( 'key' => $name, 'status' => WP_Http::INTERNAL_SERVER_ERROR )

   269 				);

   270 			}

   271 		}

   272 

   273 		return true;

   274 	}

   275 

   276 	/**

   277 	 * Updates a meta value for an object.

   278 	 *

   279 	 * @since 4.7.0

   280 	 *

   281 	 * @param int    $object_id Object ID to update.

   282 	 * @param string $meta_key  Key for the custom field.

   283 	 * @param string $name      Name for the field that is exposed in the REST API.

   284 	 * @param mixed  $value     Updated value.

   285 	 * @return bool|WP_Error True if the meta field was updated, WP_Error otherwise.

   286 	 */

   287 	protected function update_meta_value( $object_id, $meta_key, $name, $value ) {

   288 		$meta_type = $this->get_meta_type();

   289 		if ( ! current_user_can(  "edit_{$meta_type}_meta", $object_id, $meta_key ) ) {

   290 			return new WP_Error(

   291 				'rest_cannot_update',

   292 				/* translators: %s: custom field key */

   293 				sprintf( __( 'Sorry, you are not allowed to edit the %s custom field.' ), $name ),

   294 				array( 'key' => $name, 'status' => rest_authorization_required_code() )

   295 			);

   296 		}

   297 

   298 		$meta_key   = wp_slash( $meta_key );

   299 		$meta_value = wp_slash( $value );

   300 

   301 		// Do the exact same check for a duplicate value as in update_metadata() to avoid update_metadata() returning false.

   302 		$old_value = get_metadata( $meta_type, $object_id, $meta_key );

   303 

   304 		if ( 1 === count( $old_value ) ) {

   305 			if ( $old_value[0] === $meta_value ) {

   306 				return true;

   307 			}

   308 		}

   309 

   310 		if ( ! update_metadata( $meta_type, $object_id, $meta_key, $meta_value ) ) {

   311 			return new WP_Error(

   312 				'rest_meta_database_error',

   313 				__( 'Could not update meta value in database.' ),

   314 				array( 'key' => $name, 'status' => WP_Http::INTERNAL_SERVER_ERROR )

   315 			);

   316 		}

   317 

   318 		return true;

   319 	}

   320 

   321 	/**

   322 	 * Retrieves all the registered meta fields.

   323 	 *

   324 	 * @since 4.7.0

   325 	 *

   326 	 * @return array Registered fields.

   327 	 */

   328 	protected function get_registered_fields() {

   329 		$registered = array();

   330 

   331 		$meta_type    = $this->get_meta_type();

   332 		$meta_subtype = $this->get_meta_subtype();

   333 

   334 		$meta_keys = get_registered_meta_keys( $meta_type );

   335 		if ( ! empty( $meta_subtype ) ) {

   336 			$meta_keys = array_merge( $meta_keys, get_registered_meta_keys( $meta_type, $meta_subtype ) );

   337 		}

   338 

   339 		foreach ( $meta_keys as $name => $args ) {

   340 			if ( empty( $args['show_in_rest'] ) ) {

   341 				continue;

   342 			}

   343 

   344 			$rest_args = array();

   345 

   346 			if ( is_array( $args['show_in_rest'] ) ) {

   347 				$rest_args = $args['show_in_rest'];

   348 			}

   349 

   350 			$default_args = array(

   351 				'name'             => $name,

   352 				'single'           => $args['single'],

   353 				'type'             => ! empty( $args['type'] ) ? $args['type'] : null,

   354 				'schema'           => array(),

   355 				'prepare_callback' => array( $this, 'prepare_value' ),

   356 			);

   357 

   358 			$default_schema = array(

   359 				'type'        => $default_args['type'],

   360 				'description' => empty( $args['description'] ) ? '' : $args['description'],

   361 				'default'     => isset( $args['default'] ) ? $args['default'] : null,

   362 			);

   363 

   364 			$rest_args = array_merge( $default_args, $rest_args );

   365 			$rest_args['schema'] = array_merge( $default_schema, $rest_args['schema'] );

   366 

   367 			$type = ! empty( $rest_args['type'] ) ? $rest_args['type'] : null;

   368 			$type = ! empty( $rest_args['schema']['type'] ) ? $rest_args['schema']['type'] : $type;

   369 

   370 			if ( ! in_array( $type, array( 'string', 'boolean', 'integer', 'number' ) ) ) {

   371 				continue;

   372 			}

   373 

   374 			if ( empty( $rest_args['single'] ) ) {

   375 				$rest_args['schema']['items'] = array(

   376 					'type' => $rest_args['type'],

   377 				);

   378 				$rest_args['schema']['type'] = 'array';

   379 			}

   380 

   381 			$registered[ $name ] = $rest_args;

   382 		}

   383 

   384 		return $registered;

   385 	}

   386 

   387 	/**

   388 	 * Retrieves the object's meta schema, conforming to JSON Schema.

   389 	 *

   390 	 * @since 4.7.0

   391 	 *

   392 	 * @return array Field schema data.

   393 	 */

   394 	public function get_field_schema() {

   395 		$fields = $this->get_registered_fields();

   396 

   397 		$schema = array(

   398 			'description' => __( 'Meta fields.' ),

   399 			'type'        => 'object',

   400 			'context'     => array( 'view', 'edit' ),

   401 			'properties'  => array(),

   402 			'arg_options' => array(

   403 				'sanitize_callback' => null,

   404 				'validate_callback' => array( $this, 'check_meta_is_array' ),

   405 			),

   406 		);

   407 

   408 		foreach ( $fields as $args ) {

   409 			$schema['properties'][ $args['name'] ] = $args['schema'];

   410 		}

   411 

   412 		return $schema;

   413 	}

   414 

   415 	/**

   416 	 * Prepares a meta value for output.

   417 	 *

   418 	 * Default preparation for meta fields. Override by passing the

   419 	 * `prepare_callback` in your `show_in_rest` options.

   420 	 *

   421 	 * @since 4.7.0

   422 	 *

   423 	 * @param mixed           $value   Meta value from the database.

   424 	 * @param WP_REST_Request $request Request object.

   425 	 * @param array           $args    REST-specific options for the meta key.

   426 	 * @return mixed Value prepared for output. If a non-JsonSerializable object, null.

   427 	 */

   428 	public static function prepare_value( $value, $request, $args ) {

   429 		$type = $args['schema']['type'];

   430 

   431 		// For multi-value fields, check the item type instead.

   432 		if ( 'array' === $type && ! empty( $args['schema']['items']['type'] ) ) {

   433 			$type = $args['schema']['items']['type'];

   434 		}

   435 

   436 		switch ( $type ) {

   437 			case 'string':

   438 				$value = (string) $value;

   439 				break;

   440 			case 'integer':

   441 				$value = (int) $value;

   442 				break;

   443 			case 'number':

   444 				$value = (float) $value;

   445 				break;

   446 			case 'boolean':

   447 				$value = (bool) $value;

   448 				break;

   449 		}

   450 

   451 		// Don't allow objects to be output.

   452 		if ( is_object( $value ) && ! ( $value instanceof JsonSerializable ) ) {

   453 			return null;

   454 		}

   455 

   456 		return $value;

   457 	}

   458 

   459 	/**

   460 	 * Check the 'meta' value of a request is an associative array.

   461 	 *

   462 	 * @since 4.7.0

   463 	 *

   464 	 * @param  mixed           $value   The meta value submitted in the request.

   465 	 * @param  WP_REST_Request $request Full details about the request.

   466 	 * @param  string          $param   The parameter name.

   467 	 * @return WP_Error|string The meta array, if valid, otherwise an error.

   468 	 */

   469 	public function check_meta_is_array( $value, $request, $param ) {

   470 		if ( ! is_array( $value ) ) {

   471 			return false;

   472 		}

   473 

   474 		return $value;

   475 	}

   476 }