类文档

WP_REST_Request

💡 云策文档标注

概述

WP_REST_Request 是 WordPress REST API 的核心类,用于封装和处理 REST 请求数据。它实现了 ArrayAccess 接口,允许以数组方式访问参数,并提供了多种方法来管理请求的 HTTP 方法、头部、参数和验证。

关键要点

  • WP_REST_Request 实现了 ArrayAccess 接口,但注意它不使用 ArrayObject,在某些情况下可能表现出非数组行为。
  • 当通过 ArrayAccess 访问参数时,WordPress 不会区分不同请求方法(如 GET 和 POST)中同名的参数,默认优先使用 POST 数据;如需精确控制,应使用 get_body_params()、get_url_params() 等方法。
  • 类提供了丰富的参数管理方法,包括 get_param()、set_param()、get_params() 等,支持从 URL、查询字符串、请求体、JSON 和默认值中获取参数。
  • 参数优先级顺序由 get_parameter_order() 方法定义,可通过 rest_request_parameter_order 过滤器进行自定义。
  • 支持请求验证(has_valid_params())和参数清理(sanitize_params()),基于路由注册时定义的参数属性。
  • 可以从完整 URL 创建请求对象(from_url() 静态方法),方便处理外部请求。

代码示例

// 手动创建请求对象
$request = new WP_REST_Request( 'GET', '/wp/v2/posts' );

// 从 URL 创建请求对象
$request = WP_REST_Request::from_url( 'http://example.com/wp-json/wp/v2/posts' );

// 设置查询参数
$request->set_query_params( array( 'categories' => 10, 'per_page' => 30 ) );

// 设置 JSON 请求体
$request->set_header( 'content-type', 'application/json' );
$request->set_body( $json_data );

// 设置 POST 请求体参数
$request->set_body_params( array( 'foo' => 1, 'bar' => 2 ) );

// 执行请求并处理响应
$response = rest_do_request( $request );
if ( $response->is_error() ) {
    $error = $response->as_error();
    wp_die( 'An error occurred: ' . $error->get_error_message() );
}
$data = $response->get_data();

注意事项

  • 使用 ArrayAccess 时,注意参数优先级可能导致意外行为,建议在需要精确控制时使用特定方法(如 get_body_params())。
  • JSON 参数支持懒解析,仅在需要时解析,提高性能。
  • 请求验证和清理依赖于路由注册时定义的参数属性(如 required、sanitize_callback、validate_callback)。

📄 原文内容

Core class used to implement a REST request object.

Description

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.

Methods

Name Description
WP_REST_Request::__construct Constructor.
WP_REST_Request::add_header Appends a header value for the given header.
WP_REST_Request::canonicalize_header_name Canonicalizes the header name.
WP_REST_Request::from_url Retrieves a WP_REST_Request object from a full URL.
WP_REST_Request::get_attributes Retrieves the attributes for the request.
WP_REST_Request::get_body Retrieves the request body content.
WP_REST_Request::get_body_params Retrieves parameters from the body.
WP_REST_Request::get_content_type Retrieves the Content-Type of the request.
WP_REST_Request::get_default_params Retrieves the default parameters.
WP_REST_Request::get_file_params Retrieves multipart file parameters from the body.
WP_REST_Request::get_header Retrieves the given header from the request.
WP_REST_Request::get_header_as_array Retrieves header values from the request.
WP_REST_Request::get_headers Retrieves all headers from the request.
WP_REST_Request::get_json_params Retrieves the parameters from a JSON-formatted body.
WP_REST_Request::get_method Retrieves the HTTP method for the request.
WP_REST_Request::get_param Retrieves a parameter from the request.
WP_REST_Request::get_parameter_order Retrieves the parameter priority order.
WP_REST_Request::get_params Retrieves merged parameters from the request.
WP_REST_Request::get_query_params Retrieves parameters from the query string.
WP_REST_Request::get_route Retrieves the route that matched the request.
WP_REST_Request::get_url_params Retrieves parameters from the route itself.
WP_REST_Request::has_param Checks if a parameter exists in the request.
WP_REST_Request::has_valid_params Checks whether this request is valid according to its attributes.
WP_REST_Request::is_json_content_type Checks if the request has specified a JSON Content-Type.
WP_REST_Request::is_method Determines if the request is the given method.
WP_REST_Request::offsetExists
WP_REST_Request::offsetGet
WP_REST_Request::offsetSet
WP_REST_Request::offsetUnset
WP_REST_Request::parse_body_params Parses the request body parameters.
WP_REST_Request::parse_json_params Parses the JSON parameters.
WP_REST_Request::remove_header Removes all values for a header.
WP_REST_Request::sanitize_params Sanitizes (where possible) the params on the request.
WP_REST_Request::set_attributes Sets the attributes for the request.
WP_REST_Request::set_body Sets body content.
WP_REST_Request::set_body_params Sets parameters from the body.
WP_REST_Request::set_default_params Sets default parameters.
WP_REST_Request::set_file_params Sets multipart file parameters from the body.
WP_REST_Request::set_header Sets the header on request.
WP_REST_Request::set_headers Sets headers on the request.
WP_REST_Request::set_method Sets HTTP method for the request.
WP_REST_Request::set_param Sets a parameter on the request.
WP_REST_Request::set_query_params Sets parameters from the query string.
WP_REST_Request::set_route Sets the route that matched the request.
WP_REST_Request::set_url_params Sets parameters from the route.

Source

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 );
	}
}

Changelog

Version Description
4.4.0 Introduced.

User Contributed Notes

  1. Skip to note 6 content

    If you want to supply json data to request manually (since your js client might do the same, you can emulate the same behaviour in your test ), you can do it like this way.

    $request   = new WP_REST_Request( 'POST', 'your route here' );
    		$request->set_header( 'content-type', 'application/json' );
    		$request->set_body( $json_data );

    and get the data by

    $request->get_params();

  2. Skip to note 7 content

    Request objects can be created in one of two ways: manually, or from a URL.

    // Manual creation:
    $request = new WP_REST_Request( 'GET', '/wp/v2/posts' );
    
    // From a URL (if your site is at <a href="http://example.com/" rel="nofollow ugc">http://example.com/</a>):
    $request = WP_REST_Request::from_url( 'http://example.com/wp-json/wp/v2/posts' );
    // GET by default; to change the method, you can then run:
    $request->set_method( 'POST' );

    The from_url method is a convenience method to create the object for you, and is recommended when you have the full URL for an endpoint. The constructor is recommended in all other cases.

  3. Skip to note 10 content

    A complete request and response code

    $request = new WP_REST_Request( 'GET', '/wp/v2/posts' );
    $response = rest_do_request( $request );
     
    if ( $response->is_error() ) {
        // Convert to a WP_Error object.
        $error = $response->as_error();
        $message = $error->get_error_message();
        $error_data = $error->get_error_data();
        $status = isset( $error_data['status'] ) ? $error_data['status'] : 500;
        wp_die( sprintf( 'An error occurred: %s (%d)', $message, $error_data ) );
    }
     
    $data = $response->get_data();
    $headers = $response->get_headers();
    echo "<p>Success! Here's the data:</p>";
    var_dump( $data );

    Comment edited by @audrasjb on November 18, 2022, to address an issue in the code snippet, reported by @leprincenoir.