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

/**
* Core class used to implement the WordPress REST API server.
*
* @since 4.4.0
*/
#[AllowDynamicProperties]
class WP_REST_Server {

/**
* Alias for GET transport method.
*
* @since 4.4.0
* @var string
*/
const READABLE = 'GET';

/**
* Alias for POST transport method.
*
* @since 4.4.0
* @var string
*/
const CREATABLE = 'POST';

/**
* Alias for POST, PUT, PATCH transport methods together.
*
* @since 4.4.0
* @var string
*/
const EDITABLE = 'POST, PUT, PATCH';

/**
* Alias for DELETE transport method.
*
* @since 4.4.0
* @var string
*/
const DELETABLE = 'DELETE';

/**
* Alias for GET, POST, PUT, PATCH & DELETE transport methods together.
*
* @since 4.4.0
* @var string
*/
const ALLMETHODS = 'GET, POST, PUT, PATCH, DELETE';

/**
* Namespaces registered to the server.
*
* @since 4.4.0
* @var array
*/
protected $namespaces = array();

/**
* Endpoints registered to the server.
*
* @since 4.4.0
* @var array
*/
protected $endpoints = array();

/**
* Options defined for the routes.
*
* @since 4.4.0
* @var array
*/
protected $route_options = array();

/**
* Caches embedded requests.
*
* @since 5.4.0
* @var array
*/
protected $embed_cache = array();

/**
* Stores request objects that are currently being handled.
*
* @since 6.5.0
* @var array
*/
protected $dispatching_requests = array();

/**
* Instantiates the REST server.
*
* @since 4.4.0
*/
public function __construct() {
$this->endpoints = array(
// Meta endpoints.
'/' => array(
'callback' => array( $this, 'get_index' ),
'methods' => 'GET',
'args' => array(
'context' => array(
'default' => 'view',
),
),
),
'/batch/v1' => array(
'callback' => array( $this, 'serve_batch_request_v1' ),
'methods' => 'POST',
'args' => array(
'validation' => array(
'type' => 'string',
'enum' => array( 'require-all-validate', 'normal' ),
'default' => 'normal',
),
'requests' => array(
'required' => true,
'type' => 'array',
'maxItems' => $this->get_max_batch_size(),
'items' => array(
'type' => 'object',
'properties' => array(
'method' => array(
'type' => 'string',
'enum' => array( 'POST', 'PUT', 'PATCH', 'DELETE' ),
'default' => 'POST',
),
'path' => array(
'type' => 'string',
'required' => true,
),
'body' => array(
'type' => 'object',
'properties' => array(),
'additionalProperties' => true,
),
'headers' => array(
'type' => 'object',
'properties' => array(),
'additionalProperties' => array(
'type' => array( 'string', 'array' ),
'items' => array(
'type' => 'string',
),
),
),
),
),
),
),
),
);
}


/**
* Checks the authentication headers if supplied.
*
* @since 4.4.0
*
* @return WP_Error|null|true WP_Error indicates unsuccessful login, null indicates successful
* or no authentication provided
*/
public function check_authentication() {
/**
* Filters REST API authentication errors.
*
* This is used to pass a WP_Error from an authentication method back to
* the API.
*
* Authentication methods should check first if they're being used, as
* multiple authentication methods can be enabled on a site (cookies,
* HTTP basic auth, OAuth). If the authentication method hooked in is
* not actually being attempted, null should be returned to indicate
* another authentication method should check instead. Similarly,
* callbacks should ensure the value is `null` before checking for
* errors.
*
* A WP_Error instance can be returned if an error occurs, and this should
* match the format used by API methods internally (that is, the `status`
* data should be used). A callback can return `true` to indicate that
* the authentication method was used, and it succeeded.
*
* @since 4.4.0
*
* @param WP_Error|null|true $errors WP_Error if authentication error, null if authentication
* method wasn't used, true if authentication succeeded.
*/
return apply_filters( 'rest_authentication_errors', null );
}

/**
* Converts an error to a response object.
*
* This iterates over all error codes and messages to change it into a flat
* array. This enables simpler client behavior, as it is represented as a
* list in JSON rather than an object/map.
*
* @since 4.4.0
* @since 5.7.0 Converted to a wrapper of {@see rest_convert_error_to_response()}.
*
* @param WP_Error $error WP_Error instance.
* @return WP_REST_Response List of associative arrays with code and message keys.
*/
protected function error_to_response( $error ) {
return rest_convert_error_to_response( $error );
}

/**
* Retrieves an appropriate error representation in JSON.
*
* Note: This should only be used in WP_REST_Server::serve_request(), as it
* cannot handle WP_Error internally. All callbacks and other internal methods
* should instead return a WP_Error with the data set to an array that includes
* a 'status' key, with the value being the HTTP status to send.
*
* @since 4.4.0
*
* @param string $code WP_Error-style code.
* @param string $message Human-readable message.
* @param int $status Optional. HTTP status code to send. Default null.
* @return string JSON representation of the error
*/
protected function json_error( $code, $message, $status = null ) {
if ( $status ) {
$this->set_status( $status );
}

$error = compact( 'code', 'message' );

return wp_json_encode( $error );
}

/**
* Gets the encoding options passed to {@see wp_json_encode}.
*
* @since 6.1.0
*
* @param \WP_REST_Request $request The current request object.
*
* @return int The JSON encode options.
*/
protected function get_json_encode_options( WP_REST_Request $request ) {
$options = 0;

if ( $request->has_param( '_pretty' ) ) {
$options |= JSON_PRETTY_PRINT;
}

/**
* Filters the JSON encoding options used to send the REST API response.
*
* @since 6.1.0
*
* @param int $options JSON encoding options {@see json_encode()}.
* @param WP_REST_Request $request Current request object.
*/
return apply_filters( 'rest_json_encode_options', $options, $request );
}

/**
* Handles serving a REST API request.
*
* Matches the current server URI to a route and runs the first matching
* callback then outputs a JSON representation of the returned value.
*
* @since 4.4.0
*
* @see WP_REST_Server::dispatch()
*
* @global WP_User $current_user The currently authenticated user.
*
* @param string $path Optional. The request route. If not set, `$_SERVER['PATH_INFO']` will be used.
* Default null.
* @return null|false Null if not served and a HEAD request, false otherwise.
*/
public function serve_request( $path = null ) {
/* @var WP_User|null $current_user */
global $current_user;

if ( $current_user instanceof WP_User && ! $current_user->exists() ) {
/*
* If there is no current user authenticated via other means, clear
* the cached lack of user, so that an authenticate check can set it
* properly.
*
* This is done because for authentications such as Application
* Passwords, we don't want it to be accepted unless the current HTTP
* request is a REST API request, which can't always be identified early
* enough in evaluation.
*/
$current_user = null;
}

/**
* Filters whether JSONP is enabled for the REST API.
*
* @since 4.4.0
*
* @param bool $jsonp_enabled Whether JSONP is enabled. Default true.
*/
$jsonp_enabled = apply_filters( 'rest_jsonp_enabled', true );

$jsonp_callback = false;
if ( isset( $_GET['_jsonp'] ) ) {
$jsonp_callback = $_GET['_jsonp'];
}

$content_type = ( $jsonp_callback && $jsonp_enabled ) ? 'application/javascript' : 'application/json';
$this->send_header( 'Content-Type', $content_type . '; charset=' . get_option( 'blog_charset' ) );
$this->send_header( 'X-Robots-Tag', 'noindex' );

$api_root = get_rest_url();
if ( ! empty( $api_root ) ) {
$this->send_header( 'Link', '<' . sanitize_url( $api_root ) . '>; rel="https://api.w.org/"' );
}

/*
* Mitigate possible JSONP Flash attacks.
*
* https://miki.it/blog/2014/7/8/abusing-jsonp-with-rosetta-flash/
*/
$this->send_header( 'X-Content-Type-Options', 'nosniff' );

/**
* Filters whether the REST API is enabled.
*
* @since 4.4.0
* @deprecated 4.7.0 Use the {@see 'rest_authentication_errors'} filter to
* restrict access to the REST API.
*
* @param bool $rest_enabled Whether the REST API is enabled. Default true.
*/
apply_filters_deprecated(
'rest_enabled',
array( true ),
'4.7.0',
'rest_authentication_errors',
sprintf(
/* translators: %s: rest_authentication_errors */
__( 'The REST API can no longer be completely disabled, the %s filter can be used to restrict access to the API, instead.' ),
'rest_authentication_errors'
)
);

if ( $jsonp_callback ) {
if ( ! $jsonp_enabled ) {
echo $this->json_error( 'rest_callback_disabled', __( 'JSONP support is disabled on this site.' ), 400 );
return false;
}

if ( ! wp_check_jsonp_callback( $jsonp_callback ) ) {
echo $this->json_error( 'rest_callback_invalid', __( 'Invalid JSONP callback function.' ), 400 );
return false;
}
}

if ( empty( $path ) ) {
if ( isset( $_SERVER['PATH_INFO'] ) ) {
$path = $_SERVER['PATH_INFO'];
} else {
$path = '/';
}
}

$request = new WP_REST_Request( $_SERVER['REQUEST_METHOD'], $path );

$request->set_query_params( wp_unslash( $_GET ) );
$request->set_body_params( wp_unslash( $_POST ) );
$request->set_file_params( $_FILES );
$request->set_headers( $this->get_headers( wp_unslash( $_SERVER ) ) );
$request->set_body( self::get_raw_data() );

/*
* HTTP method override for clients that can't use PUT/PATCH/DELETE. First, we check
* $_GET['_method']. If that is not set, we check for the HTTP_X_HTTP_METHOD_OVERRIDE
* header.
*/
$method_overridden = false;
if ( isset( $_GET['_method'] ) ) {
$request->set_method( $_GET['_method'] );
} elseif ( isset( $_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE'] ) ) {
$request->set_method( $_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE'] );
$method_overridden = true;
}

$expose_headers = array( 'X-WP-Total', 'X-WP-TotalPages', 'Link' );

/**
* Filters the list of response headers that are exposed to REST API CORS requests.
*
* @since 5.5.0
* @since 6.3.0 The `$request` parameter was added.
*
* @param string[] $expose_headers The list of response headers to expose.
* @param WP_REST_Request $request The request in context.
*/
$expose_headers = apply_filters( 'rest_exposed_cors_headers', $expose_headers, $request );

$this->send_header( 'Access-Control-Expose-Headers', implode( ', ', $expose_headers ) );

$allow_headers = array(
'Authorization',
'X-WP-Nonce',
'Content-Disposition',
'Content-MD5',
'Content-Type',
);

/**
* Filters the list of request headers that are allowed for REST API CORS requests.
*
* The allowed headers are passed to the browser to specify which
* headers can be passed to the REST API. By default, we allow the
* Content-* headers needed to upload files to the media endpoints.
* As well as the Authorization and Nonce headers for allowing authentication.
*
* @since 5.5.0
* @since 6.3.0 The `$request` parameter was added.
*
* @param string[] $allow_headers The list of request headers to allow.
* @param WP_REST_Request $request The request in context.
*/
$allow_headers = apply_filters( 'rest_allowed_cors_headers', $allow_headers, $request );

$this->send_header( 'Access-Control-Allow-Headers', implode( ', ', $allow_headers ) );

$result = $this->check_authentication();

if ( ! is_wp_error( $result ) ) {
$result = $this->dispatch( $request );
}

// Normalize to either WP_Error or WP_REST_Response...
$result = rest_ensure_response( $result );

// ...then convert WP_Error across.
if ( is_wp_error( $result ) ) {
$result = $this->error_to_response( $result );
}

/**
* Filters the REST API response.
*
* Allows modification of the response before returning.
*
* @since 4.4.0
* @since 4.5.0 Applied to embedded responses.
*
* @param WP_HTTP_Response $result Result to send to the client. Usually a `WP_REST_Response`.
* @param WP_REST_Server $server Server instance.
* @param WP_REST_Request $request Request used to generate the response.
*/
$result = apply_filters( 'rest_post_dispatch', rest_ensure_response( $result ), $this, $request );

// Wrap the response in an envelope if asked for.
if ( isset( $_GET['_envelope'] ) ) {
$embed = isset( $_GET['_embed'] ) ? rest_parse_embed_param( $_GET['_embed'] ) : false;
$result = $this->envelope_response( $result, $embed );
}

// Send extra data from response objects.
$headers = $result->get_headers();
$this->send_headers( $headers );

$code = $result->get_status();
$this->set_status( $code );

/**
* Filters whether to send no-cache headers on a REST API request.
*
* @since 4.4.0
* @since 6.3.2 Moved the block to catch the filter added on rest_cookie_check_errors() from wp-includes/rest-api.php.
*
* @param bool $rest_send_nocache_headers Whether to send no-cache headers.
*/
$send_no_cache_headers = apply_filters( 'rest_send_nocache_headers', is_user_logged_in() );

/*
* Send no-cache headers if $send_no_cache_headers is true,
* OR if the HTTP_X_HTTP_METHOD_OVERRIDE is used but resulted a 4xx response code.
*/
if ( $send_no_cache_headers || ( true === $method_overridden && str_starts_with( $code, '4' ) ) ) {
foreach ( wp_get_nocache_headers() as $header => $header_value ) {
if ( empty( $header_value ) ) {
$this->remove_header( $header );
} else {
$this->send_header( $header, $header_value );
}
}
}

/**
* Filters whether the REST API request has already been served.
*
* Allow sending the request manually - by returning true, the API result
* will not be sent to the client.
*
* @since 4.4.0
*
* @param bool $served Whether the request has already been served.
* Default false.
* @param WP_HTTP_Response $result Result to send to the client. Usually a `WP_REST_Response`.
* @param WP_REST_Request $request Request used to generate the response.
* @param WP_REST_Server $server Server instance.
*/
$served = apply_filters( 'rest_pre_serve_request', false, $result, $request, $this );

if ( ! $served ) {
if ( 'HEAD' === $request->get_method() ) {
return null;
}

// Embed links inside the request.
$embed = isset( $_GET['_embed'] ) ? rest_parse_embed_param( $_GET['_embed'] ) : false;
$result = $this->response_to_data( $result, $embed );

/**
* Filters the REST API response.
*
* Allows modification of the response data after inserting
* embedded data (if any) and before echoing the response data.
*
* @since 4.8.1
*
* @param array $result Response data to send to the client.
* @param WP_REST_Server $server Server instance.
* @param WP_REST_Request $request Request used to generate the response.
*/
$result = apply_filters( 'rest_pre_echo_response', $result, $this, $request );

// The 204 response shouldn't have a body.
if ( 204 === $code || null === $result ) {
return null;
}

$result = wp_json_encode( $result, $this->get_json_encode_options( $request ) );

$json_error_message = $this->get_json_last_error();

if ( $json_error_message ) {
$this->set_status( 500 );
$json_error_obj = new WP_Error(
'rest_encode_error',
$json_error_message,
array( 'status' => 500 )
);

$result = $this->error_to_response( $json_error_obj );
$result = wp_json_encode( $result->data, $this->get_json_encode_options( $request ) );
}

if ( $jsonp_callback ) {
// Prepend '/**/' to mitigate possible JSONP Flash attacks.
// https://miki.it/blog/2014/7/8/abusing-jsonp-with-rosetta-flash/
echo '/**/' . $jsonp_callback . '(' . $result . ')';
} else {
echo $result;
}
}

return null;
}

/**
* Converts a response to data to send.
*
* @since 4.4.0
* @since 5.4.0 The `$embed` parameter can now contain a list of link relations to include.
*
* @param WP_REST_Response $response Response object.
* @param bool|string[] $embed Whether to embed all links, a filtered list of link relations, or no links.
* @return array {
* Data with sub-requests embedded.
*
* @type array $_links Links.
* @type array $_embedded Embedded objects.
* }
*/
public function response_to_data( $response, $embed ) {
$data = $response->get_data();
$links = self::get_compact_response_links( $response );

if ( ! empty( $links ) ) {
// Convert links to part of the data.
$data['_links'] = $links;
}

if ( $embed ) {
$this->embed_cache = array();
// Determine if this is a numeric array.
if ( wp_is_numeric_array( $data ) ) {
foreach ( $data as $key => $item ) {
$data[ $key ] = $this->embed_links( $item, $embed );
}
} else {
$data = $this->embed_links( $data, $embed );
}
$this->embed_cache = array();
}

return $data;
}

/**
* Retrieves links from a response.
*
* Extracts the links from a response into a structured hash, suitable for
* direct output.
*
* @since 4.4.0
*
* @param WP_REST_Response $response Response to extract links from.
* @return array Map of link relation to list of link hashes.
*/
public static function get_response_links( $response ) {
$links = $response->get_links();

if ( empty( $links ) ) {
return array();
}

// Convert links to part of the data.
$data = array();
foreach ( $links as $rel => $items ) {
$data[ $rel ] = array();

foreach ( $items as $item ) {
$attributes = $item['attributes'];
$attributes['href'] = $item['href'];

if ( 'self' !== $rel ) {
$data[ $rel ][] = $attributes;
continue;
}

$target_hints = self::get_target_hints_for_link( $attributes );
if ( $target_hints ) {
$attributes['targetHints'] = $target_hints;
}

$data[ $rel ][] = $attributes;
}
}

return $data;
}

/**
* Gets the target links for a REST API Link.
*
* @since 6.7.0
*
* @param array $link
*
* @return array|null
*/
protected static function get_target_hints_for_link( $link ) {
// Prefer targetHints that were specifically designated by the developer.
if ( isset( $link['targetHints']['allow'] ) ) {
return null;
}

$request = WP_REST_Request::from_url( $link['href'] );
if ( ! $request ) {
return null;
}

$server = rest_get_server();
$match = $server->match_request_to_handler( $request );

if ( is_wp_error( $match ) ) {
return null;
}

if ( is_wp_error( $request->has_valid_params() ) ) {
return null;
}

if ( is_wp_error( $request->sanitize_params() ) ) {
return null;
}

$target_hints = array();

$response = new WP_REST_Response();
$response->set_matched_route( $match[0] );
$response->set_matched_handler( $match[1] );
$headers = rest_send_allow_header( $response, $server, $request )->get_headers();

foreach ( $headers as $name => $value ) {
$name = WP_REST_Request::canonicalize_header_name( $name );

$target_hints[ $name ] = array_map( 'trim', explode( ',', $value ) );
}

return $target_hints;
}

/**
* Retrieves the CURIEs (compact URIs) used for relations.
*
* Extracts the links from a response into a structured hash, suitable for
* direct output.
*
* @since 4.5.0
*
* @param WP_REST_Response $response Response to extract links from.
* @return array Map of link relation to list of link hashes.
*/
public static function get_compact_response_links( $response ) {
$links = self::get_response_links( $response );

if ( empty( $links ) ) {
return array();
}

$curies = $response->get_curies();
$used_curies = array();

foreach ( $links as $rel => $items ) {

// Convert $rel URIs to their compact versions if they exist.
foreach ( $curies as $curie ) {
$href_prefix = substr( $curie['href'], 0, strpos( $curie['href'], '{rel}' ) );
if ( ! str_starts_with( $rel, $href_prefix ) ) {
continue;
}

// Relation now changes from '$uri' to '$curie:$relation'.
$rel_regex = str_replace( '\{rel\}', '(.+)', preg_quote( $curie['href'], '!' ) );
preg_match( '!' . $rel_regex . '!', $rel, $matches );
if ( $matches ) {
$new_rel = $curie['name'] . ':' . $matches[1];
$used_curies[ $curie['name'] ] = $curie;
$links[ $new_rel ] = $items;
unset( $links[ $rel ] );
break;
}
}
}

// Push the curies onto the start of the links array.
if ( $used_curies ) {
$links['curies'] = array_values( $used_curies );
}

return $links;
}

/**
* Embeds the links from the data into the request.
*
* @since 4.4.0
* @since 5.4.0 The `$embed` parameter can now contain a list of link relations to include.
*
* @param array $data Data from the request.
* @param bool|string[] $embed Whether to embed all links or a filtered list of link relations.
* @return array {
* Data with sub-requests embedded.
*
* @type array $_links Links.
* @type array $_embedded Embedded objects.
* }
*/
protected function embed_links( $data, $embed = true ) {
if ( empty( $data['_links'] ) ) {
return $data;
}

$embedded = array();

foreach ( $data['_links'] as $rel => $links ) {
/*
* If a list of relations was specified, and the link relation
* is not in the list of allowed relations, don't process the link.
*/
if ( is_array( $embed ) && ! in_array( $rel, $embed, true ) ) {
continue;
}

$embeds = array();

foreach ( $links as $item ) {
// Determine if the link is embeddable.
if ( empty( $item['embeddable'] ) ) {
// Ensure we keep the same order.
$embeds[] = array();
continue;
}

if ( ! array_key_exists( $item['href'], $this->embed_cache ) ) {
// Run through our internal routing and serve.
$request = WP_REST_Request::from_url( $item['href'] );
if ( ! $request ) {
$embeds[] = array();
continue;
}

// Embedded resources get passed context=embed.
if ( empty( $request['context'] ) ) {
$request['context'] = 'embed';
}

if ( empty( $request['per_page'] ) ) {
$matched = $this->match_request_to_handler( $request );
if ( ! is_wp_error( $matched ) && isset( $matched[1]['args']['per_page']['maximum'] ) ) {
$request['per_page'] = (int) $matched[1]['args']['per_page']['maximum'];
}
}

$response = $this->dispatch( $request );

/** This filter is documented in wp-includes/rest-api/class-wp-rest-server.php */
$response = apply_filters( 'rest_post_dispatch', rest_ensure_response( $response ), $this, $request );

$this->embed_cache[ $item['href'] ] = $this->response_to_data( $response, false );
}

$embeds[] = $this->embed_cache[ $item['href'] ];
}

// Determine if any real links were found.
$has_links = count( array_filter( $embeds ) );

if ( $has_links ) {
$embedded[ $rel ] = $embeds;
}
}

if ( ! empty( $embedded ) ) {
$data['_embedded'] = $embedded;
}

return $data;
}

/**
* Wraps the response in an envelope.
*
* The enveloping technique is used to work around browser/client
* compatibility issues. Essentially, it converts the full HTTP response to
* data instead.
*
* @since 4.4.0
* @since 6.0.0 The `$embed` parameter can now contain a list of link relations to include.
*
* @param WP_REST_Response $response Response object.
* @param bool|string[] $embed Whether to embed all links, a filtered list of link relations, or no links.
* @return WP_REST_Response New response with wrapped data
*/
public function envelope_response( $response, $embed ) {
$envelope = array(
'body' => $this->response_to_data( $response, $embed ),
'status' => $response->get_status(),
'headers' => $response->get_headers(),
);

/**
* Filters the enveloped form of a REST API response.
*
* @since 4.4.0
*
* @param array $envelope {
* Envelope data.
*
* @type array $body Response data.
* @type int $status The 3-digit HTTP status code.
* @type array $headers Map of header name to header value.
* }
* @param WP_REST_Response $response Original response data.
*/
$envelope = apply_filters( 'rest_envelope_response', $envelope, $response );

// Ensure it's still a response and return.
return rest_ensure_response( $envelope );
}

/**
* Registers a route to the server.
*
* @since 4.4.0
*
* @param string $route_namespace Namespace.
* @param string $route The REST route.
* @param array $route_args Route arguments.
* @param bool $override Optional. Whether the route should be overridden if it already exists.
* Default false.
*/
public function register_route( $route_namespace, $route, $route_args, $override = false ) {
if ( ! isset( $this->namespaces[ $route_namespace ] ) ) {
$this->namespaces[ $route_namespace ] = array();

$this->register_route(
$route_namespace,
'/' . $route_namespace,
array(
array(
'methods' => self::READABLE,
'callback' => array( $this, 'get_namespace_index' ),
'args' => array(
'namespace' => array(
'default' => $route_namespace,
),
'context' => array(
'default' => 'view',
),
),
),
)
);
}

// Associative to avoid double-registration.
$this->namespaces[ $route_namespace ][ $route ] = true;

$route_args['namespace'] = $route_namespace;

if ( $override || empty( $this->endpoints[ $route ] ) ) {
$this->endpoints[ $route ] = $route_args;
} else {
$this->endpoints[ $route ] = array_merge( $this->endpoints[ $route ], $route_args );
}
}

/**
* Retrieves the route map.
*
* The route map is an associative array with path regexes as the keys. The
* value is an indexed array with the callback function/method as the first
* item, and a bitmask of HTTP methods as the second item (see the class
* constants).
*
* Each route can be mapped to more than one callback by using an array of
* the indexed arrays. This allows mapping e.g. GET requests to one callback
* and POST requests to another.
*
* Note that the path regexes (array keys) must have @ escaped, as this is
* used as the delimiter with preg_match()
*
* @since 4.4.0
* @since 5.4.0 Added `$route_namespace` parameter.
*
* @param string $route_namespace Optionally, only return routes in the given namespace.
* @return array `'/path/regex' => array( $callback, $bitmask )` or
* `'/path/regex' => array( array( $callback, $bitmask ), ...)`.
*/
public function get_routes( $route_namespace = '' ) {
$endpoints = $this->endpoints;

if ( $route_namespace ) {
$endpoints = wp_list_filter( $endpoints, array( 'namespace' => $route_namespace ) );
}

/**
* Filters the array of available REST API endpoints.
*
* @since 4.4.0
*
* @param array $endpoints The available endpoints. An array of matching regex patterns, each mapped
* to an array of callbacks for the endpoint. These take the format
* `'/path/regex' => array( $callback, $bitmask )` or
* `'/path/regex' => array( array( $callback, $bitmask ).
*/
$endpoints = apply_filters( 'rest_endpoints', $endpoints );

// Normalize the endpoints.
$defaults = array(
'methods' => '',
'accept_json' => false,
'accept_raw' => false,
'show_in_index' => true,
'args' => array(),
);

foreach ( $endpoints as $route => &$handlers ) {

if ( isset( $handlers['callback'] ) ) {
// Single endpoint, add one deeper.
$handlers = array( $handlers );
}

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

foreach ( $handlers as $key => &$handler ) {

if ( ! is_numeric( $key ) ) {
// Route option, move it to the options.
$this->route_options[ $route ][ $key ] = $handler;
unset( $handlers[ $key ] );
continue;
}

$handler = wp_parse_args( $handler, $defaults );

// Allow comma-separated HTTP methods.
if ( is_string( $handler['methods'] ) ) {
$methods = explode( ',', $handler['methods'] );
} elseif ( is_array( $handler['methods'] ) ) {
$methods = $handler['methods'];
} else {
$methods = array();
}

$handler['methods'] = array();

foreach ( $methods as $method ) {
$method = strtoupper( trim( $method ) );
$handler['methods'][ $method ] = true;
}
}
}

return $endpoints;
}

/**
* Retrieves namespaces registered on the server.
*
* @since 4.4.0
*
* @return string[] List of registered namespaces.
*/
public function get_namespaces() {
return array_keys( $this->namespaces );
}

/**
* Retrieves specified options for a route.
*
* @since 4.4.0
*
* @param string $route Route pattern to fetch options for.
* @return array|null Data as an associative array if found, or null if not found.
*/
public function get_route_options( $route ) {
if ( ! isset( $this->route_options[ $route ] ) ) {
return null;
}

return $this->route_options[ $route ];
}

/**
* Matches the request to a callback and call it.
*
* @since 4.4.0
*
* @param WP_REST_Request $request Request to attempt dispatching.
* @return WP_REST_Response Response returned by the callback.
*/
public function dispatch( $request ) {
$this->dispatching_requests[] = $request;

/**
* Filters the pre-calculated result of a REST API dispatch request.
*
* Allow hijacking the request before dispatching by returning a non-empty. The returned value
* will be used to serve the request instead.
*
* @since 4.4.0
*
* @param mixed $result Response to replace the requested version with. Can be anything
* a normal endpoint can return, or null to not hijack the request.
* @param WP_REST_Server $server Server instance.
* @param WP_REST_Request $request Request used to generate the response.
*/
$result = apply_filters( 'rest_pre_dispatch', null, $this, $request );

if ( ! empty( $result ) ) {

// Normalize to either WP_Error or WP_REST_Response...
$result = rest_ensure_response( $result );

// ...then convert WP_Error across.
if ( is_wp_error( $result ) ) {
$result = $this->error_to_response( $result );
}

array_pop( $this->dispatching_requests );
return $result;
}

$error = null;
$matched = $this->match_request_to_handler( $request );

if ( is_wp_error( $matched ) ) {
$response = $this->error_to_response( $matched );
array_pop( $this->dispatching_requests );
return $response;
}

list( $route, $handler ) = $matched;

if ( ! is_callable( $handler['callback'] ) ) {
$error = new WP_Error(
'rest_invalid_handler',
__( 'The handler for the route is invalid.' ),
array( 'status' => 500 )
);
}

if ( ! is_wp_error( $error ) ) {
$check_required = $request->has_valid_params();
if ( is_wp_error( $check_required ) ) {
$error = $check_required;
} else {
$check_sanitized = $request->sanitize_params();
if ( is_wp_error( $check_sanitized ) ) {
$error = $check_sanitized;
}
}
}

$response = $this->respond_to_request( $request, $route, $handler, $error );
array_pop( $this->dispatching_requests );
return $response;
}

/**
* Returns whether the REST server is currently dispatching / responding to a request.
*
* This may be a standalone REST API request, or an internal request dispatched from within a regular page load.
*
* @since 6.5.0
*
* @return bool Whether the REST server is currently handling a request.
*/
public function is_dispatching() {
return (bool) $this->dispatching_requests;
}

/**
* Matches a request object to its handler.
*
* @access private
* @since 5.6.0
*
* @param WP_REST_Request $request The request object.
* @return array|WP_Error The route and request handler on success or a WP_Error instance if no handler was found.
*/
protected function match_request_to_handler( $request ) {
$method = $request->get_method();
$path = $request->get_route();

$with_namespace = array();

foreach ( $this->get_namespaces() as $namespace ) {
if ( str_starts_with( trailingslashit( ltrim( $path, '/' ) ), $namespace ) ) {
$with_namespace[] = $this->get_routes( $namespace );
}
}

if ( $with_namespace ) {
$routes = array_merge( ...$with_namespace );
} else {
$routes = $this->get_routes();
}

foreach ( $routes as $route => $handlers ) {
$match = preg_match( '@^' . $route . '$@i', $path, $matches );

if ( ! $match ) {
continue;
}

$args = array();

foreach ( $matches as $param => $value ) {
if ( ! is_int( $param ) ) {
$args[ $param ] = $value;
}
}

foreach ( $handlers as $handler ) {
$callback = $handler['callback'];

// Fallback to GET method if no HEAD method is registered.
$checked_method = $method;
if ( 'HEAD' === $method && empty( $handler['methods']['HEAD'] ) ) {
$checked_method = 'GET';
}
if ( empty( $handler['methods'][ $checked_method ] ) ) {
continue;
}

if ( ! is_callable( $callback ) ) {
return array( $route, $handler );
}

$request->set_url_params( $args );
$request->set_attributes( $handler );

$defaults = array();

foreach ( $handler['args'] as $arg => $options ) {
if ( isset( $options['default'] ) ) {
$defaults[ $arg ] = $options['default'];
}
}

$request->set_default_params( $defaults );

return array( $route, $handler );
}
}

return new WP_Error(
'rest_no_route',
__( 'No route was found matching the URL and request method.' ),
array( 'status' => 404 )
);
}

/**
* Dispatches the request to the callback handler.
*
* @access private
* @since 5.6.0
*
* @param WP_REST_Request $request The request object.
* @param string $route The matched route regex.
* @param array $handler The matched route handler.
* @param WP_Error|null $response The current error object if any.
* @return WP_REST_Response
*/
protected function respond_to_request( $request, $route, $handler, $response ) {
/**
* Filters the response before executing any REST API callbacks.
*
* Allows plugins to perform additional validation after a
* request is initialized and matched to a registered route,
* but before it is executed.
*
* Note that this filter will not be called for requests that
* fail to authenticate or match to a registered route.
*
* @since 4.7.0
*
* @param WP_REST_Response|WP_HTTP_Response|WP_Error|mixed $response Result to send to the client.
* Usually a WP_REST_Response or WP_Error.
* @param array $handler Route handler used for the request.
* @param WP_REST_Request $request Request used to generate the response.
*/
$response = apply_filters( 'rest_request_before_callbacks', $response, $handler, $request );

// Check permission specified on the route.
if ( ! is_wp_error( $response ) && ! empty( $handler['permission_callback'] ) ) {
$permission = call_user_func( $handler['permission_callback'], $request );

if ( is_wp_error( $permission ) ) {
$response = $permission;
} elseif ( false === $permission || null === $permission ) {
$response = new WP_Error(
'rest_forbidden',
__( 'Sorry, you are not allowed to do that.' ),
array( 'status' => rest_authorization_required_code() )
);
}
}

if ( ! is_wp_error( $response ) ) {
/**
* Filters the REST API dispatch request result.
*
* Allow plugins to override dispatching the request.
*
* @since 4.4.0
* @since 4.5.0 Added `$route` and `$handler` parameters.
*
* @param mixed $dispatch_result Dispatch result, will be used if not empty.
* @param WP_REST_Request $request Request used to generate the response.
* @param string $route Route matched for the request.
* @param array $handler Route handler used for the request.
*/
$dispatch_result = apply_filters( 'rest_dispatch_request', null, $request, $route, $handler );

// Allow plugins to halt the request via this filter.
if ( null !== $dispatch_result ) {
$response = $dispatch_result;
} else {
$response = call_user_func( $handler['callback'], $request );
}
}

/**
* Filters the response immediately after executing any REST API
* callbacks.
*
* Allows plugins to perform any needed cleanup, for example,
* to undo changes made during the {@see 'rest_request_before_callbacks'}
* filter.
*
* Note that this filter will not be called for requests that
* fail to authenticate or match to a registered route.
*
* Note that an endpoint's `permission_callback` can still be
* called after this filter - see `rest_send_allow_header()`.
*
* @since 4.7.0
*
* @param WP_REST_Response|WP_HTTP_Response|WP_Error|mixed $response Result to send to the client.
* Usually a WP_REST_Response or WP_Error.
* @param array $handler Route handler used for the request.
* @param WP_REST_Request $request Request used to generate the response.
*/
$response = apply_filters( 'rest_request_after_callbacks', $response, $handler, $request );

if ( is_wp_error( $response ) ) {
$response = $this->error_to_response( $response );
} else {
$response = rest_ensure_response( $response );
}

$response->set_matched_route( $route );
$response->set_matched_handler( $handler );

return $response;
}

/**
* Returns if an error occurred during most recent JSON encode/decode.
*
* Strings to be translated will be in format like
* "Encoding error: Maximum stack depth exceeded".
*
* @since 4.4.0
*
* @return false|string Boolean false or string error message.
*/
protected function get_json_last_error() {
$last_error_code = json_last_error();

if ( JSON_ERROR_NONE === $last_error_code || empty( $last_error_code ) ) {
return false;
}

return json_last_error_msg();
}

/**
* Retrieves the site index.
*
* This endpoint describes the capabilities of the site.
*
* @since 4.4.0
*
* @param array $request {
* Request.
*
* @type string $context Context.
* }
* @return WP_REST_Response The API root index data.
*/
public function get_index( $request ) {
// General site data.
$available = array(
'name' => get_option( 'blogname' ),
'description' => get_option( 'blogdescription' ),
'url' => get_option( 'siteurl' ),
'home' => home_url(),
'gmt_offset' => get_option( 'gmt_offset' ),
'timezone_string' => get_option( 'timezone_string' ),
'page_for_posts' => (int) get_option( 'page_for_posts' ),
'page_on_front' => (int) get_option( 'page_on_front' ),
'show_on_front' => get_option( 'show_on_front' ),
'namespaces' => array_keys( $this->namespaces ),
'authentication' => array(),
'routes' => $this->get_data_for_routes( $this->get_routes(), $request['context'] ),
);

$response = new WP_REST_Response( $available );

$fields = isset( $request['_fields'] ) ? $request['_fields'] : '';
$fields = wp_parse_list( $fields );
if ( empty( $fields ) ) {
$fields[] = '_links';
}

if ( $request->has_param( '_embed' ) ) {
$fields[] = '_embedded';
}

if ( rest_is_field_included( '_links', $fields ) || rest_is_field_included( '_embedded', $fields ) ) {
$response->add_link( 'help', 'https://developer.wordpress.org/rest-api/' );
$this->add_active_theme_link_to_index( $response );
$this->add_site_logo_to_index( $response );
$this->add_site_icon_to_index( $response );
} else {
if ( rest_is_field_included( 'site_logo', $fields ) ) {
$this->add_site_logo_to_index( $response );
}
if ( rest_is_field_included( 'site_icon', $fields ) || rest_is_field_included( 'site_icon_url', $fields ) ) {
$this->add_site_icon_to_index( $response );
}
}

/**
* Filters the REST API root index data.
*
* This contains the data describing the API. This includes information
* about supported authentication schemes, supported namespaces, routes
* available on the API, and a small amount of data about the site.
*
* @since 4.4.0
* @since 6.0.0 Added `$request` parameter.
*
* @param WP_REST_Response $response Response data.
* @param WP_REST_Request $request Request data.
*/
return apply_filters( 'rest_index', $response, $request );
}

/**
* Adds a link to the active theme for users who have proper permissions.
*
* @since 5.7.0
*
* @param WP_REST_Response $response REST API response.
*/
protected function add_active_theme_link_to_index( WP_REST_Response $response ) {
$should_add = current_user_can( 'switch_themes' ) || current_user_can( 'manage_network_themes' );

if ( ! $should_add && current_user_can( 'edit_posts' ) ) {
$should_add = true;
}

if ( ! $should_add ) {
foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) {
if ( current_user_can( $post_type->cap->edit_posts ) ) {
$should_add = true;
break;
}
}
}

if ( $should_add ) {
$theme = wp_get_theme();
$response->add_link( 'https://api.w.org/active-theme', rest_url( 'wp/v2/themes/' . $theme->get_stylesheet() ) );
}
}

/**
* Exposes the site logo through the WordPress REST API.
*
* This is used for fetching this information when user has no rights
* to update settings.
*
* @since 5.8.0
*
* @param WP_REST_Response $response REST API response.
*/
protected function add_site_logo_to_index( WP_REST_Response $response ) {
$site_logo_id = get_theme_mod( 'custom_logo', 0 );

$this->add_image_to_index( $response, $site_logo_id, 'site_logo' );
}

/**
* Exposes the site icon through the WordPress REST API.
*
* This is used for fetching this information when user has no rights
* to update settings.
*
* @since 5.9.0
*
* @param WP_REST_Response $response REST API response.
*/
protected function add_site_icon_to_index( WP_REST_Response $response ) {
$site_icon_id = get_option( 'site_icon', 0 );

$this->add_image_to_index( $response, $site_icon_id, 'site_icon' );

$response->data['site_icon_url'] = get_site_icon_url();
}

/**
* Exposes an image through the WordPress REST API.
* This is used for fetching this information when user has no rights
* to update settings.
*
* @since 5.9.0
*
* @param WP_REST_Response $response REST API response.
* @param int $image_id Image attachment ID.
* @param string $type Type of Image.
*/
protected function add_image_to_index( WP_REST_Response $response, $image_id, $type ) {
$response->data[ $type ] = (int) $image_id;
if ( $image_id ) {
$response->add_link(
'https://api.w.org/featuredmedia',
rest_url( rest_get_route_for_post( $image_id ) ),
array(
'embeddable' => true,
'type' => $type,
)
);
}
}

/**
* Retrieves the index for a namespace.
*
* @since 4.4.0
*
* @param WP_REST_Request $request REST request instance.
* @return WP_REST_Response|WP_Error WP_REST_Response instance if the index was found,
* WP_Error if the namespace isn't set.
*/
public function get_namespace_index( $request ) {
$namespace = $request['namespace'];

if ( ! isset( $this->namespaces[ $namespace ] ) ) {
return new WP_Error(
'rest_invalid_namespace',
__( 'The specified namespace could not be found.' ),
array( 'status' => 404 )
);
}

$routes = $this->namespaces[ $namespace ];
$endpoints = array_intersect_key( $this->get_routes(), $routes );

$data = array(
'namespace' => $namespace,
'routes' => $this->get_data_for_routes( $endpoints, $request['context'] ),
);
$response = rest_ensure_response( $data );

// Link to the root index.
$response->add_link( 'up', rest_url( '/' ) );

/**
* Filters the REST API namespace index data.
*
* This typically is just the route data for the namespace, but you can
* add any data you'd like here.
*
* @since 4.4.0
*
* @param WP_REST_Response $response Response data.
* @param WP_REST_Request $request Request data. The namespace is passed as the 'namespace' parameter.
*/
return apply_filters( 'rest_namespace_index', $response, $request );
}

/**
* Retrieves the publicly-visible data for routes.
*
* @since 4.4.0
*
* @param array $routes Routes to get data for.
* @param string $context Optional. Context for data. Accepts 'view' or 'help'. Default 'view'.
* @return array[] Route data to expose in indexes, keyed by route.
*/
public function get_data_for_routes( $routes, $context = 'view' ) {
$available = array();

// Find the available routes.
foreach ( $routes as $route => $callbacks ) {
$data = $this->get_data_for_route( $route, $callbacks, $context );
if ( empty( $data ) ) {
continue;
}

/**
* Filters the publicly-visible data for a single REST API route.
*
* @since 4.4.0
*
* @param array $data Publicly-visible data for the route.
*/
$available[ $route ] = apply_filters( 'rest_endpoints_description', $data );
}

/**
* Filters the publicly-visible data for REST API routes.
*
* This data is exposed on indexes and can be used by clients or
* developers to investigate the site and find out how to use it. It
* acts as a form of self-documentation.
*
* @since 4.4.0
*
* @param array[] $available Route data to expose in indexes, keyed by route.
* @param array $routes Internal route data as an associative array.
*/
return apply_filters( 'rest_route_data', $available, $routes );
}

/**
* Retrieves publicly-visible data for the route.
*
* @since 4.4.0
*
* @param string $route Route to get data for.
* @param array $callbacks Callbacks to convert to data.
* @param string $context Optional. Context for the data. Accepts 'view' or 'help'. Default 'view'.
* @return array|null Data for the route, or null if no publicly-visible data.
*/
public function get_data_for_route( $route, $callbacks, $context = 'view' ) {
$data = array(
'namespace' => '',
'methods' => array(),
'endpoints' => array(),
);

$allow_batch = false;

if ( isset( $this->route_options[ $route ] ) ) {
$options = $this->route_options[ $route ];

if ( isset( $options['namespace'] ) ) {
$data['namespace'] = $options['namespace'];
}

$allow_batch = isset( $options['allow_batch'] ) ? $options['allow_batch'] : false;

if ( isset( $options['schema'] ) && 'help' === $context ) {
$data['schema'] = call_user_func( $options['schema'] );
}
}

$allowed_schema_keywords = array_flip( rest_get_allowed_schema_keywords() );

$route = preg_replace( '#\(\?P<(\w+?)>.*?\)#', '{$1}', $route );

foreach ( $callbacks as $callback ) {
// Skip to the next route if any callback is hidden.
if ( empty( $callback['show_in_index'] ) ) {
continue;
}

$data['methods'] = array_merge( $data['methods'], array_keys( $callback['methods'] ) );
$endpoint_data = array(
'methods' => array_keys( $callback['methods'] ),
);

$callback_batch = isset( $callback['allow_batch'] ) ? $callback['allow_batch'] : $allow_batch;

if ( $callback_batch ) {
$endpoint_data['allow_batch'] = $callback_batch;
}

if ( isset( $callback['args'] ) ) {
$endpoint_data['args'] = array();

foreach ( $callback['args'] as $key => $opts ) {
if ( is_string( $opts ) ) {
$opts = array( $opts => 0 );
} elseif ( ! is_array( $opts ) ) {
$opts = array();
}
$arg_data = array_intersect_key( $opts, $allowed_schema_keywords );
$arg_data['required'] = ! empty( $opts['required'] );

$endpoint_data['args'][ $key ] = $arg_data;
}
}

$data['endpoints'][] = $endpoint_data;

// For non-variable routes, generate links.
if ( ! str_contains( $route, '{' ) ) {
$data['_links'] = array(
'self' => array(
array(
'href' => rest_url( $route ),
),
),
);
}
}

if ( empty( $data['methods'] ) ) {
// No methods supported, hide the route.
return null;
}

return $data;
}

/**
* Gets the maximum number of requests that can be included in a batch.
*
* @since 5.6.0
*
* @return int The maximum requests.
*/
protected function get_max_batch_size() {
/**
* Filters the maximum number of REST API requests that can be included in a batch.
*
* @since 5.6.0
*
* @param int $max_size The maximum size.
*/
return apply_filters( 'rest_get_max_batch_size', 25 );
}

/**
* Serves the batch/v1 request.
*
* @since 5.6.0
*
* @param WP_REST_Request $batch_request The batch request object.
* @return WP_REST_Response The generated response object.
*/
public function serve_batch_request_v1( WP_REST_Request $batch_request ) {
$requests = array();

foreach ( $batch_request['requests'] as $args ) {
$parsed_url = wp_parse_url( $args['path'] );

if ( false === $parsed_url ) {
$requests[] = new WP_Error( 'parse_path_failed', __( 'Could not parse the path.' ), array( 'status' => 400 ) );

continue;
}

$single_request = new WP_REST_Request( isset( $args['method'] ) ? $args['method'] : 'POST', $parsed_url['path'] );

if ( ! empty( $parsed_url['query'] ) ) {
$query_args = array();
wp_parse_str( $parsed_url['query'], $query_args );
$single_request->set_query_params( $query_args );
}

if ( ! empty( $args['body'] ) ) {
$single_request->set_body_params( $args['body'] );
}

if ( ! empty( $args['headers'] ) ) {
$single_request->set_headers( $args['headers'] );
}

$requests[] = $single_request;
}

$matches = array();
$validation = array();
$has_error = false;

foreach ( $requests as $single_request ) {
$match = $this->match_request_to_handler( $single_request );
$matches[] = $match;
$error = null;

if ( is_wp_error( $match ) ) {
$error = $match;
}

if ( ! $error ) {
list( $route, $handler ) = $match;

if ( isset( $handler['allow_batch'] ) ) {
$allow_batch = $handler['allow_batch'];
} else {
$route_options = $this->get_route_options( $route );
$allow_batch = isset( $route_options['allow_batch'] ) ? $route_options['allow_batch'] : false;
}

if ( ! is_array( $allow_batch ) || empty( $allow_batch['v1'] ) ) {
$error = new WP_Error(
'rest_batch_not_allowed',
__( 'The requested route does not support batch requests.' ),
array( 'status' => 400 )
);
}
}

if ( ! $error ) {
$check_required = $single_request->has_valid_params();
if ( is_wp_error( $check_required ) ) {
$error = $check_required;
}
}

if ( ! $error ) {
$check_sanitized = $single_request->sanitize_params();
if ( is_wp_error( $check_sanitized ) ) {
$error = $check_sanitized;
}
}

if ( $error ) {
$has_error = true;
$validation[] = $error;
} else {
$validation[] = true;
}
}

$responses = array();

if ( $has_error && 'require-all-validate' === $batch_request['validation'] ) {
foreach ( $validation as $valid ) {
if ( is_wp_error( $valid ) ) {
$responses[] = $this->envelope_response( $this->error_to_response( $valid ), false )->get_data();
} else {
$responses[] = null;
}
}

return new WP_REST_Response(
array(
'failed' => 'validation',
'responses' => $responses,
),
WP_Http::MULTI_STATUS
);
}

foreach ( $requests as $i => $single_request ) {
$clean_request = clone $single_request;
$clean_request->set_url_params( array() );
$clean_request->set_attributes( array() );
$clean_request->set_default_params( array() );

/** This filter is documented in wp-includes/rest-api/class-wp-rest-server.php */
$result = apply_filters( 'rest_pre_dispatch', null, $this, $clean_request );

if ( empty( $result ) ) {
$match = $matches[ $i ];
$error = null;

if ( is_wp_error( $validation[ $i ] ) ) {
$error = $validation[ $i ];
}

if ( is_wp_error( $match ) ) {
$result = $this->error_to_response( $match );
} else {
list( $route, $handler ) = $match;

if ( ! $error && ! is_callable( $handler['callback'] ) ) {
$error = new WP_Error(
'rest_invalid_handler',
__( 'The handler for the route is invalid' ),
array( 'status' => 500 )
);
}

$result = $this->respond_to_request( $single_request, $route, $handler, $error );
}
}

/** This filter is documented in wp-includes/rest-api/class-wp-rest-server.php */
$result = apply_filters( 'rest_post_dispatch', rest_ensure_response( $result ), $this, $single_request );

$responses[] = $this->envelope_response( $result, false )->get_data();
}

return new WP_REST_Response( array( 'responses' => $responses ), WP_Http::MULTI_STATUS );
}

/**
* Sends an HTTP status code.
*
* @since 4.4.0
*
* @param int $code HTTP status.
*/
protected function set_status( $code ) {
status_header( $code );
}

/**
* Sends an HTTP header.
*
* @since 4.4.0
*
* @param string $key Header key.
* @param string $value Header value.
*/
public function send_header( $key, $value ) {
/*
* Sanitize as per RFC2616 (Section 4.2):
*
* Any LWS that occurs between field-content MAY be replaced with a
* single SP before interpreting the field value or forwarding the
* message downstream.
*/
$value = preg_replace( '/\s+/', ' ', $value );
header( sprintf( '%s: %s', $key, $value ) );
}

/**
* Sends multiple HTTP headers.
*
* @since 4.4.0
*
* @param array $headers Map of header name to header value.
*/
public function send_headers( $headers ) {
foreach ( $headers as $key => $value ) {
$this->send_header( $key, $value );
}
}

/**
* Removes an HTTP header from the current response.
*
* @since 4.8.0
*
* @param string $key Header key.
*/
public function remove_header( $key ) {
header_remove( $key );
}

/**
* Retrieves the raw request entity (body).
*
* @since 4.4.0
*
* @global string $HTTP_RAW_POST_DATA Raw post data.
*
* @return string Raw request data.
*/
public static function get_raw_data() {
// phpcs:disable PHPCompatibility.Variables.RemovedPredefinedGlobalVariables.http_raw_post_dataDeprecatedRemoved
global $HTTP_RAW_POST_DATA;

// $HTTP_RAW_POST_DATA was deprecated in PHP 5.6 and removed in PHP 7.0.
if ( ! isset( $HTTP_RAW_POST_DATA ) ) {
$HTTP_RAW_POST_DATA = file_get_contents( 'php://input' );
}

return $HTTP_RAW_POST_DATA;
// phpcs:enable
}

/**
* Extracts headers from a PHP-style $_SERVER array.
*
* @since 4.4.0
*
* @param array $server Associative array similar to `$_SERVER`.
* @return array Headers extracted from the input.
*/
public function get_headers( $server ) {
$headers = array();

// CONTENT_* headers are not prefixed with HTTP_.
$additional = array(
'CONTENT_LENGTH' => true,
'CONTENT_MD5' => true,
'CONTENT_TYPE' => true,
);

foreach ( $server as $key => $value ) {
if ( str_starts_with( $key, 'HTTP_' ) ) {
$headers[ substr( $key, 5 ) ] = $value;
} elseif ( 'REDIRECT_HTTP_AUTHORIZATION' === $key && empty( $server['HTTP_AUTHORIZATION'] ) ) {
/*
* In some server configurations, the authorization header is passed in this alternate location.
* Since it would not be passed in in both places we do not check for both headers and resolve.
*/
$headers['AUTHORIZATION'] = $value;
} elseif ( isset( $additional[ $key ] ) ) {
$headers[ $key ] = $value;
}
}

return $headers;
}
}