source: trunk/src/wp-includes/rest-api/class-wp-rest-request.php

<?php
/**
 * REST API: WP_REST_Request class
 *
 * @package WordPress
 * @subpackage REST_API
 * @since 4.4.0
 */

/**
 * Core class used to implement a REST request object.
 *
 * Contains data from the request, to be passed to the callback.
 *
 * Note: This implements ArrayAccess, and acts as an array of parameters when
 * used in that manner. It does not use ArrayObject (as we cannot rely on SPL),
 * so be aware it may have non-array behavior in some cases.
 *
 * Note: When using features provided by ArrayAccess, be aware that WordPress deliberately
 * does not distinguish between arguments of the same name for different request methods.
 * For instance, in a request with `GET id=1` and `POST id=2`, `$request['id']` will equal
 * 2 (`POST`) not 1 (`GET`). For more precision between request methods, use
 * WP_REST_Request::get_body_params(), WP_REST_Request::get_url_params(), etc.
 *
 * @since 4.4.0
 *
 * @link https://www.php.net/manual/en/class.arrayaccess.php
 */
#[AllowDynamicProperties]
class WP_REST_Request implements ArrayAccess {

        /**
         * HTTP method.
         *
         * @since 4.4.0
         * @var string
         */
        protected $method = '';

        /**
         * Parameters passed to the request.
         *
         * These typically come from the `$_GET`, `$_POST` and `$_FILES`
         * superglobals when being created from the global scope.
         *
         * @since 4.4.0
         * @var array Contains GET, POST and FILES keys mapping to arrays of data.
         */
        protected $params;

        /**
         * HTTP headers for the request.
         *
         * @since 4.4.0
         * @var array Map of key to value. Key is always lowercase, as per HTTP specification.
         */
        protected $headers = array();

        /**
         * Body data.
         *
         * @since 4.4.0
         * @var string Binary data from the request.
         */
        protected $body = null;

        /**
         * Route matched for the request.
         *
         * @since 4.4.0
         * @var string
         */
        protected $route;

        /**
         * Attributes (options) for the route that was matched.
         *
         * This is the options array used when the route was registered, typically
         * containing the callback as well as the valid methods for the route.
         *
         * @since 4.4.0
         * @var array Attributes for the request.
         */
        protected $attributes = array();

        /**
         * Used to determine if the JSON data has been parsed yet.
         *
         * Allows lazy-parsing of JSON data where possible.
         *
         * @since 4.4.0
         * @var bool
         */
        protected $parsed_json = false;

        /**
         * Used to determine if the body data has been parsed yet.
         *
         * @since 4.4.0
         * @var bool
         */
        protected $parsed_body = false;

        /**
         * Constructor.
         *
         * @since 4.4.0
         *
         * @param string $method     Optional. Request method. Default empty.
         * @param string $route      Optional. Request route. Default empty.
         * @param array  $attributes Optional. Request attributes. Default empty array.
         */
        public function __construct( $method = '', $route = '', $attributes = array() ) {
                $this->params = array(
                        'URL'      => array(),
                        'GET'      => array(),
                        'POST'     => array(),
                        'FILES'    => array(),

                        // See parse_json_params.
                        'JSON'     => null,

                        'defaults' => array(),
                );

                $this->set_method( $method );
                $this->set_route( $route );
                $this->set_attributes( $attributes );
        }

        /**
         * Retrieves the HTTP method for the request.
         *
         * @since 4.4.0
         *
         * @return string HTTP method.
         */
        public function get_method() {
                return $this->method;
        }

        /**
         * Sets HTTP method for the request.
         *
         * @since 4.4.0
         *
         * @param string $method HTTP method.
         */
        public function set_method( $method ) {
                $this->method = strtoupper( $method );
        }

        /**
         * Retrieves all headers from the request.
         *
         * @since 4.4.0
         *
         * @return array Map of key to value. Key is always lowercase, as per HTTP specification.
         */
        public function get_headers() {
                return $this->headers;
        }

        /**
         * Determines if the request is the given method.
         *
         * @since 6.8.0
         *
         * @param string $method HTTP method.
         * @return bool Whether the request is of the given method.
         */
        public function is_method( $method ) {
                return $this->get_method() === strtoupper( $method );
        }

        /**
         * Canonicalizes the header name.
         *
         * Ensures that header names are always treated the same regardless of
         * source. Header names are always case-insensitive.
         *
         * Note that we treat `-` (dashes) and `_` (underscores) as the same
         * character, as per header parsing rules in both Apache and nginx.
         *
         * @link https://stackoverflow.com/q/18185366
         * @link https://www.nginx.com/resources/wiki/start/topics/tutorials/config_pitfalls/#missing-disappearing-http-headers
         * @link https://nginx.org/en/docs/http/ngx_http_core_module.html#underscores_in_headers
         *
         * @since 4.4.0
         *
         * @param string $key Header name.
         * @return string Canonicalized name.
         */
        public static function canonicalize_header_name( $key ) {
                $key = strtolower( $key );
                $key = str_replace( '-', '_', $key );

                return $key;
        }

        /**
         * Retrieves the given header from the request.
         *
         * If the header has multiple values, they will be concatenated with a comma
         * as per the HTTP specification. Be aware that some non-compliant headers
         * (notably cookie headers) cannot be joined this way.
         *
         * @since 4.4.0
         *
         * @param string $key Header name, will be canonicalized to lowercase.
         * @return string|null String value if set, null otherwise.
         */
        public function get_header( $key ) {
                $key = $this->canonicalize_header_name( $key );

                if ( ! isset( $this->headers[ $key ] ) ) {
                        return null;
                }

                return implode( ',', $this->headers[ $key ] );
        }

        /**
         * Retrieves header values from the request.
         *
         * @since 4.4.0
         *
         * @param string $key Header name, will be canonicalized to lowercase.
         * @return array|null List of string values if set, null otherwise.
         */
        public function get_header_as_array( $key ) {
                $key = $this->canonicalize_header_name( $key );

                if ( ! isset( $this->headers[ $key ] ) ) {
                        return null;
                }

                return $this->headers[ $key ];
        }

        /**
         * Sets the header on request.
         *
         * @since 4.4.0
         *
         * @param string $key   Header name.
         * @param string $value Header value, or list of values.
         */
        public function set_header( $key, $value ) {
                $key   = $this->canonicalize_header_name( $key );
                $value = (array) $value;

                $this->headers[ $key ] = $value;
        }

        /**
         * Appends a header value for the given header.
         *
         * @since 4.4.0
         *
         * @param string $key   Header name.
         * @param string $value Header value, or list of values.
         */
        public function add_header( $key, $value ) {
                $key   = $this->canonicalize_header_name( $key );
                $value = (array) $value;

                if ( ! isset( $this->headers[ $key ] ) ) {
                        $this->headers[ $key ] = array();
                }

                $this->headers[ $key ] = array_merge( $this->headers[ $key ], $value );
        }

        /**
         * Removes all values for a header.
         *
         * @since 4.4.0
         *
         * @param string $key Header name.
         */
        public function remove_header( $key ) {
                $key = $this->canonicalize_header_name( $key );
                unset( $this->headers[ $key ] );
        }

        /**
         * Sets headers on the request.
         *
         * @since 4.4.0
         *
         * @param array $headers  Map of header name to value.
         * @param bool  $override If true, replace the request's headers. Otherwise, merge with existing.
         */
        public function set_headers( $headers, $override = true ) {
                if ( true === $override ) {
                        $this->headers = array();
                }

                foreach ( $headers as $key => $value ) {
                        $this->set_header( $key, $value );
                }
        }

        /**
         * Retrieves the Content-Type of the request.
         *
         * @since 4.4.0
         *
         * @return array|null Map containing 'value' and 'parameters' keys
         *                    or null when no valid Content-Type header was
         *                    available.
         */
        public function get_content_type() {
                $value = $this->get_header( 'Content-Type' );
                if ( empty( $value ) ) {
                        return null;
                }

                $parameters = '';
                if ( strpos( $value, ';' ) ) {
                        list( $value, $parameters ) = explode( ';', $value, 2 );
                }

                $value = strtolower( $value );
                if ( ! str_contains( $value, '/' ) ) {
                        return null;
                }

                // Parse type and subtype out.
                list( $type, $subtype ) = explode( '/', $value, 2 );

                $data = compact( 'value', 'type', 'subtype', 'parameters' );
                $data = array_map( 'trim', $data );

                return $data;
        }

        /**
         * Checks if the request has specified a JSON Content-Type.
         *
         * @since 5.6.0
         *
         * @return bool True if the Content-Type header is JSON.
         */
        public function is_json_content_type() {
                $content_type = $this->get_content_type();

                return isset( $content_type['value'] ) && wp_is_json_media_type( $content_type['value'] );
        }

        /**
         * Retrieves the parameter priority order.
         *
         * Used when checking parameters in WP_REST_Request::get_param().
         *
         * @since 4.4.0
         *
         * @return string[] Array of types to check, in order of priority.
         */
        protected function get_parameter_order() {
                $order = array();

                if ( $this->is_json_content_type() ) {
                        $order[] = 'JSON';
                }

                $this->parse_json_params();

                // Ensure we parse the body data.
                $body = $this->get_body();

                if ( 'POST' !== $this->method && ! empty( $body ) ) {
                        $this->parse_body_params();
                }

                $accepts_body_data = array( 'POST', 'PUT', 'PATCH', 'DELETE' );
                if ( in_array( $this->method, $accepts_body_data, true ) ) {
                        $order[] = 'POST';
                }

                $order[] = 'GET';
                $order[] = 'URL';
                $order[] = 'defaults';

                /**
                 * Filters the parameter priority order for a REST API request.
                 *
                 * The order affects which parameters are checked when using WP_REST_Request::get_param()
                 * and family. This acts similarly to PHP's `request_order` setting.
                 *
                 * @since 4.4.0
                 *
                 * @param string[]        $order   Array of types to check, in order of priority.
                 * @param WP_REST_Request $request The request object.
                 */
                return apply_filters( 'rest_request_parameter_order', $order, $this );
        }

        /**
         * Retrieves a parameter from the request.
         *
         * @since 4.4.0
         *
         * @param string $key Parameter name.
         * @return mixed|null Value if set, null otherwise.
         */
        public function get_param( $key ) {
                $order = $this->get_parameter_order();

                foreach ( $order as $type ) {
                        // Determine if we have the parameter for this type.
                        if ( isset( $this->params[ $type ][ $key ] ) ) {
                                return $this->params[ $type ][ $key ];
                        }
                }

                return null;
        }

        /**
         * Checks if a parameter exists in the request.
         *
         * This allows distinguishing between an omitted parameter,
         * and a parameter specifically set to null.
         *
         * @since 5.3.0
         *
         * @param string $key Parameter name.
         * @return bool True if a param exists for the given key.
         */
        public function has_param( $key ) {
                $order = $this->get_parameter_order();

                foreach ( $order as $type ) {
                        if ( is_array( $this->params[ $type ] ) && array_key_exists( $key, $this->params[ $type ] ) ) {
                                return true;
                        }
                }

                return false;
        }

        /**
         * Sets a parameter on the request.
         *
         * If the given parameter key exists in any parameter type an update will take place,
         * otherwise a new param will be created in the first parameter type (respecting
         * get_parameter_order()).
         *
         * @since 4.4.0
         *
         * @param string $key   Parameter name.
         * @param mixed  $value Parameter value.
         */
        public function set_param( $key, $value ) {
                $order     = $this->get_parameter_order();
                $found_key = false;

                foreach ( $order as $type ) {
                        if ( 'defaults' !== $type && is_array( $this->params[ $type ] ) && array_key_exists( $key, $this->params[ $type ] ) ) {
                                $this->params[ $type ][ $key ] = $value;
                                $found_key                     = true;
                        }
                }

                if ( ! $found_key ) {
                        $this->params[ $order[0] ][ $key ] = $value;
                }
        }

        /**
         * Retrieves merged parameters from the request.
         *
         * The equivalent of get_param(), but returns all parameters for the request.
         * Handles merging all the available values into a single array.
         *
         * @since 4.4.0
         *
         * @return array Map of key to value.
         */
        public function get_params() {
                $order = $this->get_parameter_order();
                $order = array_reverse( $order, true );

                $params = array();
                foreach ( $order as $type ) {
                        /*
                         * array_merge() / the "+" operator will mess up
                         * numeric keys, so instead do a manual foreach.
                         */
                        foreach ( (array) $this->params[ $type ] as $key => $value ) {
                                $params[ $key ] = $value;
                        }
                }

                // Exclude rest_route if pretty permalinks are not enabled.
                if ( ! get_option( 'permalink_structure' ) ) {
                        unset( $params['rest_route'] );
                }

                return $params;
        }

        /**
         * Retrieves parameters from the route itself.
         *
         * These are parsed from the URL using the regex.
         *
         * @since 4.4.0
         *
         * @return array Parameter map of key to value.
         */
        public function get_url_params() {
                return $this->params['URL'];
        }

        /**
         * Sets parameters from the route.
         *
         * Typically, this is set after parsing the URL.
         *
         * @since 4.4.0
         *
         * @param array $params Parameter map of key to value.
         */
        public function set_url_params( $params ) {
                $this->params['URL'] = $params;
        }

        /**
         * Retrieves parameters from the query string.
         *
         * These are the parameters you'd typically find in `$_GET`.
         *
         * @since 4.4.0
         *
         * @return array Parameter map of key to value.
         */
        public function get_query_params() {
                return $this->params['GET'];
        }

        /**
         * Sets parameters from the query string.
         *
         * Typically, this is set from `$_GET`.
         *
         * @since 4.4.0
         *
         * @param array $params Parameter map of key to value.
         */
        public function set_query_params( $params ) {
                $this->params['GET'] = $params;
        }

        /**
         * Retrieves parameters from the body.
         *
         * These are the parameters you'd typically find in `$_POST`.
         *
         * @since 4.4.0
         *
         * @return array Parameter map of key to value.
         */
        public function get_body_params() {
                return $this->params['POST'];
        }

        /**
         * Sets parameters from the body.
         *
         * Typically, this is set from `$_POST`.
         *
         * @since 4.4.0
         *
         * @param array $params Parameter map of key to value.
         */
        public function set_body_params( $params ) {
                $this->params['POST'] = $params;
        }

        /**
         * Retrieves multipart file parameters from the body.
         *
         * These are the parameters you'd typically find in `$_FILES`.
         *
         * @since 4.4.0
         *
         * @return array Parameter map of key to value.
         */
        public function get_file_params() {
                return $this->params['FILES'];
        }

        /**
         * Sets multipart file parameters from the body.
         *
         * Typically, this is set from `$_FILES`.
         *
         * @since 4.4.0
         *
         * @param array $params Parameter map of key to value.
         */
        public function set_file_params( $params ) {
                $this->params['FILES'] = $params;
        }

        /**
         * Retrieves the default parameters.
         *
         * These are the parameters set in the route registration.
         *
         * @since 4.4.0
         *
         * @return array Parameter map of key to value.
         */
        public function get_default_params() {
                return $this->params['defaults'];
        }

        /**
         * Sets default parameters.
         *
         * These are the parameters set in the route registration.
         *
         * @since 4.4.0
         *
         * @param array $params Parameter map of key to value.
         */
        public function set_default_params( $params ) {
                $this->params['defaults'] = $params;
        }

        /**
         * Retrieves the request body content.
         *
         * @since 4.4.0
         *
         * @return string Binary data from the request body.
         */
        public function get_body() {
                return $this->body;
        }

        /**
         * Sets body content.
         *
         * @since 4.4.0
         *
         * @param string $data Binary data from the request body.
         */
        public function set_body( $data ) {
                $this->body = $data;

                // Enable lazy parsing.
                $this->parsed_json    = false;
                $this->parsed_body    = false;
                $this->params['JSON'] = null;
        }

        /**
         * Retrieves the parameters from a JSON-formatted body.
         *
         * @since 4.4.0
         *
         * @return array Parameter map of key to value.
         */
        public function get_json_params() {
                // Ensure the parameters have been parsed out.
                $this->parse_json_params();

                return $this->params['JSON'];
        }

        /**
         * Parses the JSON parameters.
         *
         * Avoids parsing the JSON data until we need to access it.
         *
         * @since 4.4.0
         * @since 4.7.0 Returns error instance if value cannot be decoded.
         * @return true|WP_Error True if the JSON data was passed or no JSON data was provided, WP_Error if invalid JSON was passed.
         */
        protected function parse_json_params() {
                if ( $this->parsed_json ) {
                        return true;
                }

                $this->parsed_json = true;

                // Check that we actually got JSON.
                if ( ! $this->is_json_content_type() ) {
                        return true;
                }

                $body = $this->get_body();
                if ( empty( $body ) ) {
                        return true;
                }

                $params = json_decode( $body, true );

                /*
                 * Check for a parsing error.
                 */
                if ( null === $params && JSON_ERROR_NONE !== json_last_error() ) {
                        // Ensure subsequent calls receive error instance.
                        $this->parsed_json = false;

                        $error_data = array(
                                'status'             => WP_Http::BAD_REQUEST,
                                'json_error_code'    => json_last_error(),
                                'json_error_message' => json_last_error_msg(),
                        );

                        return new WP_Error( 'rest_invalid_json', __( 'Invalid JSON body passed.' ), $error_data );
                }

                $this->params['JSON'] = $params;

                return true;
        }

        /**
         * Parses the request body parameters.
         *
         * Parses out URL-encoded bodies for request methods that aren't supported
         * natively by PHP.
         *
         * @since 4.4.0
         */
        protected function parse_body_params() {
                if ( $this->parsed_body ) {
                        return;
                }

                $this->parsed_body = true;

                /*
                 * Check that we got URL-encoded. Treat a missing Content-Type as
                 * URL-encoded for maximum compatibility.
                 */
                $content_type = $this->get_content_type();

                if ( ! empty( $content_type ) && 'application/x-www-form-urlencoded' !== $content_type['value'] ) {
                        return;
                }

                parse_str( $this->get_body(), $params );

                /*
                 * Add to the POST parameters stored internally. If a user has already
                 * set these manually (via `set_body_params`), don't override them.
                 */
                $this->params['POST'] = array_merge( $params, $this->params['POST'] );
        }

        /**
         * Retrieves the route that matched the request.
         *
         * @since 4.4.0
         *
         * @return string Route matching regex.
         */
        public function get_route() {
                return $this->route;
        }

        /**
         * Sets the route that matched the request.
         *
         * @since 4.4.0
         *
         * @param string $route Route matching regex.
         */
        public function set_route( $route ) {
                $this->route = $route;
        }

        /**
         * Retrieves the attributes for the request.
         *
         * These are the options for the route that was matched.
         *
         * @since 4.4.0
         *
         * @return array Attributes for the request.
         */
        public function get_attributes() {
                return $this->attributes;
        }

        /**
         * Sets the attributes for the request.
         *
         * @since 4.4.0
         *
         * @param array $attributes Attributes for the request.
         */
        public function set_attributes( $attributes ) {
                $this->attributes = $attributes;
        }

        /**
         * Sanitizes (where possible) the params on the request.
         *
         * This is primarily based off the sanitize_callback param on each registered
         * argument.
         *
         * @since 4.4.0
         *
         * @return true|WP_Error True if parameters were sanitized, WP_Error if an error occurred during sanitization.
         */
        public function sanitize_params() {
                $attributes = $this->get_attributes();

                // No arguments set, skip sanitizing.
                if ( empty( $attributes['args'] ) ) {
                        return true;
                }

                $order = $this->get_parameter_order();

                $invalid_params  = array();
                $invalid_details = array();

                foreach ( $order as $type ) {
                        if ( empty( $this->params[ $type ] ) ) {
                                continue;
                        }

                        foreach ( $this->params[ $type ] as $key => $value ) {
                                if ( ! isset( $attributes['args'][ $key ] ) ) {
                                        continue;
                                }

                                $param_args = $attributes['args'][ $key ];

                                // If the arg has a type but no sanitize_callback attribute, default to rest_parse_request_arg.
                                if ( ! array_key_exists( 'sanitize_callback', $param_args ) && ! empty( $param_args['type'] ) ) {
                                        $param_args['sanitize_callback'] = 'rest_parse_request_arg';
                                }
                                // If there's still no sanitize_callback, nothing to do here.
                                if ( empty( $param_args['sanitize_callback'] ) ) {
                                        continue;
                                }

                                /** @var mixed|WP_Error $sanitized_value */
                                $sanitized_value = call_user_func( $param_args['sanitize_callback'], $value, $this, $key );

                                if ( is_wp_error( $sanitized_value ) ) {
                                        $invalid_params[ $key ]  = implode( ' ', $sanitized_value->get_error_messages() );
                                        $invalid_details[ $key ] = rest_convert_error_to_response( $sanitized_value )->get_data();
                                } else {
                                        $this->params[ $type ][ $key ] = $sanitized_value;
                                }
                        }
                }

                if ( $invalid_params ) {
                        return new WP_Error(
                                'rest_invalid_param',
                                /* translators: %s: List of invalid parameters. */
                                sprintf( __( 'Invalid parameter(s): %s' ), implode( ', ', array_keys( $invalid_params ) ) ),
                                array(
                                        'status'  => 400,
                                        'params'  => $invalid_params,
                                        'details' => $invalid_details,
                                )
                        );
                }

                return true;
        }

        /**
         * Checks whether this request is valid according to its attributes.
         *
         * @since 4.4.0
         *
         * @return true|WP_Error True if there are no parameters to validate or if all pass validation,
         *                       WP_Error if required parameters are missing.
         */
        public function has_valid_params() {
                // If JSON data was passed, check for errors.
                $json_error = $this->parse_json_params();
                if ( is_wp_error( $json_error ) ) {
                        return $json_error;
                }

                $attributes = $this->get_attributes();
                $required   = array();

                $args = empty( $attributes['args'] ) ? array() : $attributes['args'];

                foreach ( $args as $key => $arg ) {
                        $param = $this->get_param( $key );
                        if ( isset( $arg['required'] ) && true === $arg['required'] && null === $param ) {
                                $required[] = $key;
                        }
                }

                if ( ! empty( $required ) ) {
                        return new WP_Error(
                                'rest_missing_callback_param',
                                /* translators: %s: List of required parameters. */
                                sprintf( __( 'Missing parameter(s): %s' ), implode( ', ', $required ) ),
                                array(
                                        'status' => 400,
                                        'params' => $required,
                                )
                        );
                }

                /*
                 * Check the validation callbacks for each registered arg.
                 *
                 * This is done after required checking as required checking is cheaper.
                 */
                $invalid_params  = array();
                $invalid_details = array();

                foreach ( $args as $key => $arg ) {

                        $param = $this->get_param( $key );

                        if ( null !== $param && ! empty( $arg['validate_callback'] ) ) {
                                /** @var bool|\WP_Error $valid_check */
                                $valid_check = call_user_func( $arg['validate_callback'], $param, $this, $key );

                                if ( false === $valid_check ) {
                                        $invalid_params[ $key ] = __( 'Invalid parameter.' );
                                }

                                if ( is_wp_error( $valid_check ) ) {
                                        $invalid_params[ $key ]  = implode( ' ', $valid_check->get_error_messages() );
                                        $invalid_details[ $key ] = rest_convert_error_to_response( $valid_check )->get_data();
                                }
                        }
                }

                if ( $invalid_params ) {
                        return new WP_Error(
                                'rest_invalid_param',
                                /* translators: %s: List of invalid parameters. */
                                sprintf( __( 'Invalid parameter(s): %s' ), implode( ', ', array_keys( $invalid_params ) ) ),
                                array(
                                        'status'  => 400,
                                        'params'  => $invalid_params,
                                        'details' => $invalid_details,
                                )
                        );
                }

                if ( isset( $attributes['validate_callback'] ) ) {
                        $valid_check = call_user_func( $attributes['validate_callback'], $this );

                        if ( is_wp_error( $valid_check ) ) {
                                return $valid_check;
                        }

                        if ( false === $valid_check ) {
                                // A WP_Error instance is preferred, but false is supported for parity with the per-arg validate_callback.
                                return new WP_Error( 'rest_invalid_params', __( 'Invalid parameters.' ), array( 'status' => 400 ) );
                        }
                }

                return true;
        }

        /**
         * Checks if a parameter is set.
         *
         * @since 4.4.0
         *
         * @param string $offset Parameter name.
         * @return bool Whether the parameter is set.
         */
        #[ReturnTypeWillChange]
        public function offsetExists( $offset ) {
                $order = $this->get_parameter_order();

                foreach ( $order as $type ) {
                        if ( isset( $this->params[ $type ][ $offset ] ) ) {
                                return true;
                        }
                }

                return false;
        }

        /**
         * Retrieves a parameter from the request.
         *
         * @since 4.4.0
         *
         * @param string $offset Parameter name.
         * @return mixed|null Value if set, null otherwise.
         */
        #[ReturnTypeWillChange]
        public function offsetGet( $offset ) {
                return $this->get_param( $offset );
        }

        /**
         * Sets a parameter on the request.
         *
         * @since 4.4.0
         *
         * @param string $offset Parameter name.
         * @param mixed  $value  Parameter value.
         */
        #[ReturnTypeWillChange]
        public function offsetSet( $offset, $value ) {
                $this->set_param( $offset, $value );
        }

        /**
         * Removes a parameter from the request.
         *
         * @since 4.4.0
         *
         * @param string $offset Parameter name.
         */
        #[ReturnTypeWillChange]
        public function offsetUnset( $offset ) {
                $order = $this->get_parameter_order();

                // Remove the offset from every group.
                foreach ( $order as $type ) {
                        unset( $this->params[ $type ][ $offset ] );
                }
        }

        /**
         * Retrieves a WP_REST_Request object from a full URL.
         *
         * @since 4.5.0
         *
         * @param string $url URL with protocol, domain, path and query args.
         * @return WP_REST_Request|false WP_REST_Request object on success, false on failure.
         */
        public static function from_url( $url ) {
                $bits         = parse_url( $url );
                $query_params = array();

                if ( ! empty( $bits['query'] ) ) {
                        wp_parse_str( $bits['query'], $query_params );
                }

                $api_root = rest_url();
                if ( get_option( 'permalink_structure' ) && str_starts_with( $url, $api_root ) ) {
                        // Pretty permalinks on, and URL is under the API root.
                        $api_url_part = substr( $url, strlen( untrailingslashit( $api_root ) ) );
                        $route        = parse_url( $api_url_part, PHP_URL_PATH );
                } elseif ( ! empty( $query_params['rest_route'] ) ) {
                        // ?rest_route=... set directly.
                        $route = $query_params['rest_route'];
                        unset( $query_params['rest_route'] );
                }

                $request = false;
                if ( ! empty( $route ) ) {
                        $request = new WP_REST_Request( 'GET', $route );
                        $request->set_query_params( $query_params );
                }

                /**
                 * Filters the REST API request generated from a URL.
                 *
                 * @since 4.5.0
                 *
                 * @param WP_REST_Request|false $request Generated request object, or false if URL
                 *                                       could not be parsed.
                 * @param string                $url     URL the request was generated from.
                 */
                return apply_filters( 'rest_request_from_url', $request, $url );
        }
}