WP_REST_Server::get_index( WP_REST_Request $request ): WP_REST_Response

Description

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 data.

Return value

WP_REST_Response

The API root index data.

Performance profile

How much work a call to WP_REST_Server::get_index() 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

Heavy

Reads stored settings via get_option(), cached per request but not free on a cold cache.

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

99–152

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 171.

Plugin surface

4 hooks

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

Called by

0

Nothing in core calls this; the cost is only what you spend yourself.

What it touches

• optionoption read or writeget_option()called directly
• hookthird-party callbacksapply_filters()called directly
• cacheobject cachewp_cache_get()one call below WP_REST_Server::get_index()
• serializeserialisationmaybe_unserialize()one call below WP_REST_Server::get_index()

Further down the call graph this can also reach query 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 · 24 distinct outcomes

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

Hooks and filters fired · 4

4 hooks fire while WP_REST_Server::get_index() runs, in this order:

1. 1
   apply_filters( big_image_size_threshold )filterline 1386 (+26 into the body)

   Filters the "BIG image" threshold value.

2. 2
   apply_filters( image_strip_meta )filterline 1389 (+29 into the body)

   Filters whether to strip metadata from images when they're resized.

3. 3
   apply_filters( image_max_bit_depth )filterline 1400 (+40 into the body)

   Filters the maximum bit depth of resized images.

4. 4
   apply_filters( rest_index )filterline 1442 (+82 into the body)

   Filters the REST API root index data.

Uses · 14

• get_option()Retrieves an option value based on an option name.
• home_url()Retrieves the URL for the current site where the front end is accessible.
• wp_is_client_side_media_processing_enabled()Checks whether client-side media processing is enabled.
• current_user_can()Returns whether the current user has the specified capability.
• wp_get_registered_image_subsizes()Returns a normalized list of all currently registered image sub-sizes.
• apply_filters()Calls the callback functions that have been added to a filter hook.
• wp_parse_list()Converts a comma- or space-separated list of scalar values to an array.
• rest_is_field_included()Given an array of fields to include in a response, some of which may be `nested.fields`, determine whether the provided field should be included in the response body.
• WP_REST_Server::get_data_for_routes()Retrieves the publicly-visible data for routes.
• WP_REST_Server::get_routes()Retrieves the route map.
• WP_REST_Response::__construct()
• WP_REST_Server::add_active_theme_link_to_index()Adds a link to the active theme for users who have proper permissions.

Source code

View on Trac ↗View on GitHub ↗

1360	public function get_index( $request ) {1361		// General site data.1362		$available = array(1363			'name'            => get_option( 'blogname' ),1364			'description'     => get_option( 'blogdescription' ),1365			'url'             => get_option( 'siteurl' ),1366			'home'            => home_url(),1367			'gmt_offset'      => get_option( 'gmt_offset' ),1368			'timezone_string' => get_option( 'timezone_string' ),1369			'page_for_posts'  => (int) get_option( 'page_for_posts' ),1370			'page_on_front'   => (int) get_option( 'page_on_front' ),1371			'show_on_front'   => get_option( 'show_on_front' ),1372			'namespaces'      => array_keys( $this->namespaces ),1373			'authentication'  => array(),1374			'routes'          => $this->get_data_for_routes( $this->get_routes(), $request['context'] ),1375		);1376 1377		// Add media processing settings for users who can upload files.1378		if ( wp_is_client_side_media_processing_enabled() && current_user_can( 'upload_files' ) ) {1379			// Image sizes keyed by name for client-side media processing.1380			$available['image_sizes'] = array();1381			foreach ( wp_get_registered_image_subsizes() as $name => $size ) {1382				$available['image_sizes'][ $name ] = $size;1383			}1384 1385			/** This filter is documented in wp-admin/includes/image.php */1386			$available['image_size_threshold'] = (int) apply_filters( 'big_image_size_threshold', 2560, array( 0, 0 ), '', 0 );1387 1388			/** This filter is documented in wp-includes/class-wp-image-editor-imagick.php */1389			$available['image_strip_meta'] = (bool) apply_filters( 'image_strip_meta', true );1390 1391			/*1392			 * On the server, this filter receives the decoded image's actual bit depth.1393			 * The client path never decodes the image on the server, so the filter is1394			 * applied with 16 (the maximum depth the client encoder can produce) as1395			 * both the value and the current depth. The client caps its output bit1396			 * depth at the filtered value, so a plugin lowering it (e.g. to 8) takes1397			 * effect on client-generated images too.1398			 */1399			/** This filter is documented in wp-includes/class-wp-image-editor-imagick.php */1400			$available['image_max_bit_depth'] = (int) apply_filters( 'image_max_bit_depth', 16, 16 );1401		}1402 1403		$response = new WP_REST_Response( $available );1404 1405		$fields = $request['_fields'] ?? '';1406		$fields = wp_parse_list( $fields );1407		if ( empty( $fields ) ) {1408			$fields[] = '_links';1409		}1410 1411		if ( $request->has_param( '_embed' ) ) {1412			$fields[] = '_embedded';1413		}1414 1415		if ( rest_is_field_included( '_links', $fields ) || rest_is_field_included( '_embedded', $fields ) ) {1416			$response->add_link( 'help', 'https://developer.wordpress.org/rest-api/' );1417			$this->add_active_theme_link_to_index( $response );1418			$this->add_site_logo_to_index( $response );1419			$this->add_site_icon_to_index( $response );1420		} else {1421			if ( rest_is_field_included( 'site_logo', $fields ) ) {1422				$this->add_site_logo_to_index( $response );1423			}1424			if ( rest_is_field_included( 'site_icon', $fields ) || rest_is_field_included( 'site_icon_url', $fields ) ) {1425				$this->add_site_icon_to_index( $response );1426			}1427		}1428 1429		/**1430		 * Filters the REST API root index data.1431		 *1432		 * This contains the data describing the API. This includes information1433		 * about supported authentication schemes, supported namespaces, routes1434		 * available on the API, and a small amount of data about the site.1435		 *1436		 * @since 4.4.01437		 * @since 6.0.0 Added `$request` parameter.1438		 *1439		 * @param WP_REST_Response $response Response data.

Changelog

Introduced in 4.4.0. One change between 6.7.7 and 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 7.1.0 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.

Corrections

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