WP_REST_Server::dispatch( WP_REST_Request $request ): WP_REST_Response

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$requestWP_REST_Request

Request to attempt dispatching.

Return value

WP_REST_Response

Response returned by the callback.

Performance profile

How much work a call to WP_REST_Server::dispatch() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Trivial

Touches nothing outside its own arguments.

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

27–72

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 100.

Plugin surface

1 hook

Third-party callbacks on 'rest_pre_dispatch' run inside this call, and their cost is not bounded by anything here.

Called by

2

2 places in core call this, so the cost is paid more often than your own code shows.

What it touches

• hookthird-party callbacksapply_filters()called directly

Further down the call graph this can also reach query, option, cache, serialize and transient. Those are the worst case, several calls deep and usually down an error path, not what a normal call pays.

What one call costs · 9 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost WP_REST_Server::dispatch() can have, taken from its control-flow graph on PHP 8.5.

Hooks and filters fired · 1

One hook fires while WP_REST_Server::dispatch() runs, in this order:

1. 1
   apply_filters( rest_pre_dispatch )filterline 1079 (+16 into the body)

   Filters the pre-calculated result of a REST API dispatch request.

Uses · 8

• apply_filters()Calls the callback functions that have been added to a filter hook.
• rest_ensure_response()Ensures a REST response is a response object (for consistency).
• is_wp_error()Checks whether the given variable is a WordPress Error.
• __()Retrieves the translation of $text.
• WP_REST_Server::error_to_response()Converts an error to a response object.
• WP_REST_Server::match_request_to_handler()Matches a request object to its handler.
• WP_Error::__construct()Initializes the error.
• WP_REST_Server::respond_to_request()Dispatches the request to the callback handler.

Used by · 2

• WP_REST_Server::embed_links()Embeds the links from the data into the request.
• WP_REST_Server::serve_request()Handles serving a REST API request.

Source code

View on Trac ↗View on GitHub ↗

1063	public function dispatch( $request ) {1064		$this->dispatching_requests[] = $request;1065 1066		/**1067		 * Filters the pre-calculated result of a REST API dispatch request.1068		 *1069		 * Allow hijacking the request before dispatching by returning a non-empty. The returned value1070		 * will be used to serve the request instead.1071		 *1072		 * @since 4.4.01073		 *1074		 * @param mixed           $result  Response to replace the requested version with. Can be anything1075		 *                                 a normal endpoint can return, or null to not hijack the request.1076		 * @param WP_REST_Server  $server  Server instance.1077		 * @param WP_REST_Request $request Request used to generate the response.1078		 */1079		$result = apply_filters( 'rest_pre_dispatch', null, $this, $request );1080 1081		if ( ! empty( $result ) ) {1082 1083			// Normalize to either WP_Error or WP_REST_Response...1084			$result = rest_ensure_response( $result );1085 1086			// ...then convert WP_Error across.1087			if ( is_wp_error( $result ) ) {1088				$result = $this->error_to_response( $result );1089			}1090 1091			array_pop( $this->dispatching_requests );1092			return $result;1093		}1094 1095		$error   = null;1096		$matched = $this->match_request_to_handler( $request );1097 1098		if ( is_wp_error( $matched ) ) {1099			$response = $this->error_to_response( $matched );1100			array_pop( $this->dispatching_requests );1101			return $response;1102		}1103 1104		list( $route, $handler ) = $matched;1105 1106		if ( ! is_callable( $handler['callback'] ) ) {1107			$error = new WP_Error(1108				'rest_invalid_handler',1109				__( 'The handler for the route is invalid.' ),1110				array( 'status' => 500 )1111			);1112		}1113 1114		if ( ! is_wp_error( $error ) ) {1115			$check_required = $request->has_valid_params();1116			if ( is_wp_error( $check_required ) ) {1117				$error = $check_required;1118			} else {1119				$check_sanitized = $request->sanitize_params();1120				if ( is_wp_error( $check_sanitized ) ) {1121					$error = $check_sanitized;1122				}1123			}1124		}1125 1126		$response = $this->respond_to_request( $request, $route, $handler, $error );1127		array_pop( $this->dispatching_requests );1128		return $response;1129	}

Changelog

Introduced in 4.4.0. Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.0.4 tag, from src/wp-includes/rest-api/class-wp-rest-server.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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