Adding upstream version 6.4.3+dfsg1.upstream/6.4.3+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1063 insertions, 0 deletions

diff --git a/wp-includes/rest-api/class-wp-rest-request.php b/wp-includes/rest-api/class-wp-rest-request.php
new file mode 100644
index 0000000..c671fd3
--- /dev/null
+++ b/wp-includes/rest-api/class-wp-rest-request.php
@@ -0,0 +1,1063 @@
+<?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;
+	}
+
+	/**
+	 * 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;
+			}
+		}
+
+		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. In PHP 5.x, only POST has these parsed automatically.
+	 *
+	 * @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 );
+	}
+}