/wp-includes/rest-api.php

<?php 
/** 
 * REST API functions. 
 * 
 * @package WordPress 
 * @subpackage REST_API 
 * @since 4.4.0 
 */ 
 
/** 
 * Version number for our API. 
 * 
 * @var string 
 */ 
define( 'REST_API_VERSION', '2.0' ); 
 
/** 
 * Registers a REST API route. 
 * 
 * @since 4.4.0 
 * 
 * @global WP_REST_Server $wp_rest_server ResponseHandler instance (usually WP_REST_Server). 
 * 
 * @param string $namespace The first URL segment after core prefix. Should be unique to your package/plugin. 
 * @param string $route     The base URL for route you are adding. 
 * @param array  $args      Optional. Either an array of options for the endpoint, or an array of arrays for 
 *                          multiple methods. Default empty array. 
 * @param bool   $override  Optional. If the route already exists, should we override it? True overrides,  
 *                          false merges (with newer overriding if duplicate keys exist). Default false. 
 * @return bool True on success, false on error. 
 */ 
function register_rest_route( $namespace, $route, $args = array(), $override = false ) { 
  /** @var WP_REST_Server $wp_rest_server */ 
  global $wp_rest_server; 
 
  if ( empty( $namespace ) ) { 
      /** 
       * Non-namespaced routes are not allowed, with the exception of the main 
       * and namespace indexes. If you really need to register a 
       * non-namespaced route, call `WP_REST_Server::register_route` directly. 
       */ 
      _doing_it_wrong( 'register_rest_route', __( 'Routes must be namespaced with plugin or theme name and version.' ), '4.4.0' ); 
      return false; 
  } else if ( empty( $route ) ) { 
      _doing_it_wrong( 'register_rest_route', __( 'Route must be specified.' ), '4.4.0' ); 
      return false; 
  } 
 
  if ( isset( $args['callback'] ) ) { 
      // Upgrade a single set to multiple. 
      $args = array( $args ); 
  } 
 
  $defaults = array( 
      'methods' => 'GET',  
      'callback' => null,  
      'args' => array(),  
 ); 
  foreach ( $args as $key => &$arg_group ) { 
      if ( ! is_numeric( $arg_group ) ) { 
          // Route option, skip here. 
          continue; 
      } 
 
      $arg_group = array_merge( $defaults, $arg_group ); 
  } 
 
  $full_route = '/' . trim( $namespace, '/' ) . '/' . trim( $route, '/' ); 
  $wp_rest_server->register_route( $namespace, $full_route, $args, $override ); 
  return true; 
} 
 
/** 
 * Registers a new field on an existing WordPress object type. 
 * 
 * @since 4.7.0 
 * 
 * @global array $wp_rest_additional_fields Holds registered fields, organized 
 *                                          by object type. 
 * 
 * @param string|array $object_type Object(s) the field is being registered 
 *                                  to, "post"|"term"|"comment" etc. 
 * @param string $attribute         The attribute name. 
 * @param array  $args { 
 *     Optional. An array of arguments used to handle the registered field. 
 * 
 *     @type string|array|null $get_callback    Optional. The callback function used to retrieve the field 
 *                                              value. Default is 'null', the field will not be returned in 
 *                                              the response. 
 *     @type string|array|null $update_callback Optional. The callback function used to set and update the 
 *                                              field value. Default is 'null', the value cannot be set or 
 *                                              updated. 
 *     @type string|array|null $schema          Optional. The callback function used to create the schema for 
 *                                              this field. Default is 'null', no schema entry will be returned. 
 * } 
 */ 
function register_rest_field( $object_type, $attribute, $args = array() ) { 
  $defaults = array( 
      'get_callback' => null,  
      'update_callback' => null,  
      'schema' => null,  
 ); 
 
  $args = wp_parse_args( $args, $defaults ); 
 
  global $wp_rest_additional_fields; 
 
  $object_types = (array) $object_type; 
 
  foreach ( $object_types as $object_type ) { 
      $wp_rest_additional_fields[ $object_type ][ $attribute ] = $args; 
  } 
} 
 
/** 
 * Registers rewrite rules for the API. 
 * 
 * @since 4.4.0 
 * 
 * @see rest_api_register_rewrites() 
 * @global WP $wp Current WordPress environment instance. 
 */ 
function rest_api_init() { 
  rest_api_register_rewrites(); 
 
  global $wp; 
  $wp->add_query_var( 'rest_route' ); 
} 
 
/** 
 * Adds REST rewrite rules. 
 * 
 * @since 4.4.0 
 * 
 * @see add_rewrite_rule() 
 * @global WP_Rewrite $wp_rewrite 
 */ 
function rest_api_register_rewrites() { 
  global $wp_rewrite; 
 
  add_rewrite_rule( '^' . rest_get_url_prefix() . '/?$', 'index.php?rest_route=/', 'top' ); 
  add_rewrite_rule( '^' . rest_get_url_prefix() . '/(.*)?', 'index.php?rest_route=/$matches[1]', 'top' ); 
  add_rewrite_rule( '^' . $wp_rewrite->index . '/' . rest_get_url_prefix() . '/?$', 'index.php?rest_route=/', 'top' ); 
  add_rewrite_rule( '^' . $wp_rewrite->index . '/' . rest_get_url_prefix() . '/(.*)?', 'index.php?rest_route=/$matches[1]', 'top' ); 
} 
 
/** 
 * Registers the default REST API filters. 
 * 
 * Attached to the {@see 'rest_api_init'} action 
 * to make testing and disabling these filters easier. 
 * 
 * @since 4.4.0 
 */ 
function rest_api_default_filters() { 
  // Deprecated reporting. 
  add_action( 'deprecated_function_run', 'rest_handle_deprecated_function', 10, 3 ); 
  add_filter( 'deprecated_function_trigger_error', '__return_false' ); 
  add_action( 'deprecated_argument_run', 'rest_handle_deprecated_argument', 10, 3 ); 
  add_filter( 'deprecated_argument_trigger_error', '__return_false' ); 
 
  // Default serving. 
  add_filter( 'rest_pre_serve_request', 'rest_send_cors_headers' ); 
  add_filter( 'rest_post_dispatch', 'rest_send_allow_header', 10, 3 ); 
 
  add_filter( 'rest_pre_dispatch', 'rest_handle_options_request', 10, 3 ); 
} 
 
/** 
 * Registers default REST API routes. 
 * 
 * @since 4.7.0 
 */ 
function create_initial_rest_routes() { 
  foreach ( get_post_types( array( 'show_in_rest' => true ), 'objects' ) as $post_type ) { 
      $class = ! empty( $post_type->rest_controller_class ) ? $post_type->rest_controller_class : 'WP_REST_Posts_Controller'; 
 
      if ( ! class_exists( $class ) ) { 
          continue; 
      } 
      $controller = new $class( $post_type->name ); 
      if ( ! is_subclass_of( $controller, 'WP_REST_Controller' ) ) { 
          continue; 
      } 
 
      $controller->register_routes(); 
 
      if ( post_type_supports( $post_type->name, 'revisions' ) ) { 
          $revisions_controller = new WP_REST_Revisions_Controller( $post_type->name ); 
          $revisions_controller->register_routes(); 
      } 
  } 
 
  // Post types. 
  $controller = new WP_REST_Post_Types_Controller; 
  $controller->register_routes(); 
 
  // Post statuses. 
  $controller = new WP_REST_Post_Statuses_Controller; 
  $controller->register_routes(); 
 
  // Taxonomies. 
  $controller = new WP_REST_Taxonomies_Controller; 
  $controller->register_routes(); 
 
  // Terms. 
  foreach ( get_taxonomies( array( 'show_in_rest' => true ), 'object' ) as $taxonomy ) { 
      $class = ! empty( $taxonomy->rest_controller_class ) ? $taxonomy->rest_controller_class : 'WP_REST_Terms_Controller'; 
 
      if ( ! class_exists( $class ) ) { 
          continue; 
      } 
      $controller = new $class( $taxonomy->name ); 
      if ( ! is_subclass_of( $controller, 'WP_REST_Controller' ) ) { 
          continue; 
      } 
 
      $controller->register_routes(); 
  } 
 
  // Users. 
  $controller = new WP_REST_Users_Controller; 
  $controller->register_routes(); 
 
  // Comments. 
  $controller = new WP_REST_Comments_Controller; 
  $controller->register_routes(); 
 
  // Settings. 
  $controller = new WP_REST_Settings_Controller; 
  $controller->register_routes(); 
} 
 
/** 
 * Loads the REST API. 
 * 
 * @since 4.4.0 
 * 
 * @global WP             $wp             Current WordPress environment instance. 
 * @global WP_REST_Server $wp_rest_server ResponseHandler instance (usually WP_REST_Server). 
 */ 
function rest_api_loaded() { 
  if ( empty( $GLOBALS['wp']->query_vars['rest_route'] ) ) { 
      return; 
  } 
 
  /** 
   * Whether this is a REST Request. 
   * 
   * @since 4.4.0 
   * @var bool 
   */ 
  define( 'REST_REQUEST', true ); 
 
  // Initialize the server. 
  $server = rest_get_server(); 
 
  // Fire off the request. 
  $server->serve_request( untrailingslashit( $GLOBALS['wp']->query_vars['rest_route'] ) ); 
 
  // We're done. 
  die(); 
} 
 
/** 
 * Retrieves the URL prefix for any API resource. 
 * 
 * @since 4.4.0 
 * 
 * @return string Prefix. 
 */ 
function rest_get_url_prefix() { 
  /** 
   * Filters the REST URL prefix. 
   * 
   * @since 4.4.0 
   * 
   * @param string $prefix URL prefix. Default 'wp-json'. 
   */ 
  return apply_filters( 'rest_url_prefix', 'wp-json' ); 
} 
 
/** 
 * Retrieves the URL to a REST endpoint on a site. 
 * 
 * Note: The returned URL is NOT escaped. 
 * 
 * @since 4.4.0 
 * 
 * @todo Check if this is even necessary 
 * @global WP_Rewrite $wp_rewrite 
 * 
 * @param int    $blog_id Optional. Blog ID. Default of null returns URL for current blog. 
 * @param string $path    Optional. REST route. Default '/'. 
 * @param string $scheme  Optional. Sanitization scheme. Default 'rest'. 
 * @return string Full URL to the endpoint. 
 */ 
function get_rest_url( $blog_id = null, $path = '/', $scheme = 'rest' ) { 
  if ( empty( $path ) ) { 
      $path = '/'; 
  } 
 
  if ( is_multisite() && get_blog_option( $blog_id, 'permalink_structure' ) || get_option( 'permalink_structure' ) ) { 
      global $wp_rewrite; 
 
      if ( $wp_rewrite->using_index_permalinks() ) { 
          $url = get_home_url( $blog_id, $wp_rewrite->index . '/' . rest_get_url_prefix(), $scheme ); 
      } else { 
          $url = get_home_url( $blog_id, rest_get_url_prefix(), $scheme ); 
      } 
 
      $url .= '/' . ltrim( $path, '/' ); 
  } else { 
      $url = trailingslashit( get_home_url( $blog_id, '', $scheme ) ); 
 
      $path = '/' . ltrim( $path, '/' ); 
 
      $url = add_query_arg( 'rest_route', $path, $url ); 
  } 
 
  if ( is_ssl() ) { 
      // If the current host is the same as the REST URL host, force the REST URL scheme to HTTPS. 
      if ( $_SERVER['SERVER_NAME'] === parse_url( get_home_url( $blog_id ), PHP_URL_HOST ) ) { 
          $url = set_url_scheme( $url, 'https' ); 
      } 
  } 
 
  /** 
   * Filters the REST URL. 
   * 
   * Use this filter to adjust the url returned by the get_rest_url() function. 
   * 
   * @since 4.4.0 
   * 
   * @param string $url     REST URL. 
   * @param string $path    REST route. 
   * @param int    $blog_id Blog ID. 
   * @param string $scheme  Sanitization scheme. 
   */ 
  return apply_filters( 'rest_url', $url, $path, $blog_id, $scheme ); 
} 
 
/** 
 * Retrieves the URL to a REST endpoint. 
 * 
 * Note: The returned URL is NOT escaped. 
 * 
 * @since 4.4.0 
 * 
 * @param string $path   Optional. REST route. Default empty. 
 * @param string $scheme Optional. Sanitization scheme. Default 'json'. 
 * @return string Full URL to the endpoint. 
 */ 
function rest_url( $path = '', $scheme = 'json' ) { 
  return get_rest_url( null, $path, $scheme ); 
} 
 
/** 
 * Do a REST request. 
 * 
 * Used primarily to route internal requests through WP_REST_Server. 
 * 
 * @since 4.4.0 
 * 
 * @global WP_REST_Server $wp_rest_server ResponseHandler instance (usually WP_REST_Server). 
 * 
 * @param WP_REST_Request|string $request Request. 
 * @return WP_REST_Response REST response. 
 */ 
function rest_do_request( $request ) { 
  $request = rest_ensure_request( $request ); 
  return rest_get_server()->dispatch( $request ); 
} 
 
/** 
 * Retrieves the current REST server instance. 
 * 
 * Instantiates a new instance if none exists already. 
 * 
 * @since 4.5.0 
 * 
 * @global WP_REST_Server $wp_rest_server REST server instance. 
 * 
 * @return WP_REST_Server REST server instance. 
 */ 
function rest_get_server() { 
  /** @var WP_REST_Server $wp_rest_server */ 
  global $wp_rest_server; 
 
  if ( empty( $wp_rest_server ) ) { 
      /** 
       * Filters the REST Server Class. 
       * 
       * This filter allows you to adjust the server class used by the API, using a 
       * different class to handle requests. 
       * 
       * @since 4.4.0 
       * 
       * @param string $class_name The name of the server class. Default 'WP_REST_Server'. 
       */ 
      $wp_rest_server_class = apply_filters( 'wp_rest_server_class', 'WP_REST_Server' ); 
      $wp_rest_server = new $wp_rest_server_class; 
 
      /** 
       * Fires when preparing to serve an API request. 
       * 
       * Endpoint objects should be created and register their hooks on this action rather 
       * than another action to ensure they're only loaded when needed. 
       * 
       * @since 4.4.0 
       * 
       * @param WP_REST_Server $wp_rest_server Server object. 
       */ 
      do_action( 'rest_api_init', $wp_rest_server ); 
  } 
 
  return $wp_rest_server; 
} 
 
/** 
 * Ensures request arguments are a request object (for consistency). 
 * 
 * @since 4.4.0 
 * 
 * @param array|WP_REST_Request $request Request to check. 
 * @return WP_REST_Request REST request instance. 
 */ 
function rest_ensure_request( $request ) { 
  if ( $request instanceof WP_REST_Request ) { 
      return $request; 
  } 
 
  return new WP_REST_Request( 'GET', '', $request ); 
} 
 
/** 
 * Ensures a REST response is a response object (for consistency). 
 * 
 * This implements WP_HTTP_Response, allowing usage of `set_status`/`header`/etc 
 * without needing to double-check the object. Will also allow WP_Error to indicate error 
 * responses, so users should immediately check for this value. 
 * 
 * @since 4.4.0 
 * 
 * @param WP_Error|WP_HTTP_Response|mixed $response Response to check. 
 * @return WP_REST_Response|mixed If response generated an error, WP_Error, if response 
 *                                is already an instance, WP_HTTP_Response, otherwise 
 *                                returns a new WP_REST_Response instance. 
 */ 
function rest_ensure_response( $response ) { 
  if ( is_wp_error( $response ) ) { 
      return $response; 
  } 
 
  if ( $response instanceof WP_HTTP_Response ) { 
      return $response; 
  } 
 
  return new WP_REST_Response( $response ); 
} 
 
/** 
 * Handles _deprecated_function() errors. 
 * 
 * @since 4.4.0 
 * 
 * @param string $function    The function that was called. 
 * @param string $replacement The function that should have been called. 
 * @param string $version     Version. 
 */ 
function rest_handle_deprecated_function( $function, $replacement, $version ) { 
  if ( ! empty( $replacement ) ) { 
      /** translators: 1: function name, 2: WordPress version number, 3: new function name */ 
      $string = sprintf( __( '%1$s (since %2$s; use %3$s instead)' ), $function, $version, $replacement ); 
  } else { 
      /** translators: 1: function name, 2: WordPress version number */ 
      $string = sprintf( __( '%1$s (since %2$s; no alternative available)' ), $function, $version ); 
  } 
 
  header( sprintf( 'X-WP-DeprecatedFunction: %s', $string ) ); 
} 
 
/** 
 * Handles _deprecated_argument() errors. 
 * 
 * @since 4.4.0 
 * 
 * @param string $function    The function that was called. 
 * @param string $message     A message regarding the change. 
 * @param string $version     Version. 
 */ 
function rest_handle_deprecated_argument( $function, $message, $version ) { 
  if ( ! empty( $message ) ) { 
      /** translators: 1: function name, 2: WordPress version number, 3: error message */ 
      $string = sprintf( __( '%1$s (since %2$s; %3$s)' ), $function, $version, $message ); 
  } else { 
      /** translators: 1: function name, 2: WordPress version number */ 
      $string = sprintf( __( '%1$s (since %2$s; no alternative available)' ), $function, $version ); 
  } 
 
  header( sprintf( 'X-WP-DeprecatedParam: %s', $string ) ); 
} 
 
/** 
 * Sends Cross-Origin Resource Sharing headers with API requests. 
 * 
 * @since 4.4.0 
 * 
 * @param mixed $value Response data. 
 * @return mixed Response data. 
 */ 
function rest_send_cors_headers( $value ) { 
  $origin = get_http_origin(); 
 
  if ( $origin ) { 
      header( 'Access-Control-Allow-Origin: ' . esc_url_raw( $origin ) ); 
      header( 'Access-Control-Allow-Methods: OPTIONS, GET, POST, PUT, PATCH, DELETE' ); 
      header( 'Access-Control-Allow-Credentials: true' ); 
      header( 'Vary: Origin' ); 
  } 
 
  return $value; 
} 
 
/** 
 * Handles OPTIONS requests for the server. 
 * 
 * This is handled outside of the server code, as it doesn't obey normal route 
 * mapping. 
 * 
 * @since 4.4.0 
 * 
 * @param mixed           $response Current response, either response or `null` to indicate pass-through. 
 * @param WP_REST_Server  $handler  ResponseHandler instance (usually WP_REST_Server). 
 * @param WP_REST_Request $request  The request that was used to make current response. 
 * @return WP_REST_Response Modified response, either response or `null` to indicate pass-through. 
 */ 
function rest_handle_options_request( $response, $handler, $request ) { 
  if ( ! empty( $response ) || $request->get_method() !== 'OPTIONS' ) { 
      return $response; 
  } 
 
  $response = new WP_REST_Response(); 
  $data = array(); 
 
  foreach ( $handler->get_routes() as $route => $endpoints ) { 
      $match = preg_match( '@^' . $route . '$@i', $request->get_route() ); 
 
      if ( ! $match ) { 
          continue; 
      } 
 
      $data = $handler->get_data_for_route( $route, $endpoints, 'help' ); 
      $response->set_matched_route( $route ); 
      break; 
  } 
 
  $response->set_data( $data ); 
  return $response; 
} 
 
/** 
 * Sends the "Allow" header to state all methods that can be sent to the current route. 
 * 
 * @since 4.4.0 
 * 
 * @param WP_REST_Response $response Current response being served. 
 * @param WP_REST_Server   $server   ResponseHandler instance (usually WP_REST_Server). 
 * @param WP_REST_Request  $request  The request that was used to make current response. 
 * @return WP_REST_Response Response to be served, with "Allow" header if route has allowed methods. 
 */ 
function rest_send_allow_header( $response, $server, $request ) { 
  $matched_route = $response->get_matched_route(); 
 
  if ( ! $matched_route ) { 
      return $response; 
  } 
 
  $routes = $server->get_routes(); 
 
  $allowed_methods = array(); 
 
  // Get the allowed methods across the routes. 
  foreach ( $routes[ $matched_route ] as $_handler ) { 
      foreach ( $_handler['methods'] as $handler_method => $value ) { 
 
          if ( ! empty( $_handler['permission_callback'] ) ) { 
 
              $permission = call_user_func( $_handler['permission_callback'], $request ); 
 
              $allowed_methods[ $handler_method ] = true === $permission; 
          } else { 
              $allowed_methods[ $handler_method ] = true; 
          } 
      } 
  } 
 
  // Strip out all the methods that are not allowed (false values). 
  $allowed_methods = array_filter( $allowed_methods ); 
 
  if ( $allowed_methods ) { 
      $response->header( 'Allow', implode( ', ', array_map( 'strtoupper', array_keys( $allowed_methods ) ) ) ); 
  } 
 
  return $response; 
} 
 
/** 
 * Adds the REST API URL to the WP RSD endpoint. 
 * 
 * @since 4.4.0 
 * 
 * @see get_rest_url() 
 */ 
function rest_output_rsd() { 
  $api_root = get_rest_url(); 
 
  if ( empty( $api_root ) ) { 
      return; 
  } 
  ?> 
  <api name="WP-API" blogID="1" preferred="false" apiLink="<?php echo esc_url( $api_root ); ?>" /> 
  <?php 
} 
 
/** 
 * Outputs the REST API link tag into page header. 
 * 
 * @since 4.4.0 
 * 
 * @see get_rest_url() 
 */ 
function rest_output_link_wp_head() { 
  $api_root = get_rest_url(); 
 
  if ( empty( $api_root ) ) { 
      return; 
  } 
 
  echo "<link rel='https://api.w.org/' href='" . esc_url( $api_root ) . "' />\n"; 
} 
 
/** 
 * Sends a Link header for the REST API. 
 * 
 * @since 4.4.0 
 */ 
function rest_output_link_header() { 
  if ( headers_sent() ) { 
      return; 
  } 
 
  $api_root = get_rest_url(); 
 
  if ( empty( $api_root ) ) { 
      return; 
  } 
 
  header( 'Link: <' . esc_url_raw( $api_root ) . '>; rel="https://api.w.org/"', false ); 
} 
 
/** 
 * Checks for errors when using cookie-based authentication. 
 * 
 * WordPress' built-in cookie authentication is always active 
 * for logged in users. However, the API has to check nonces 
 * for each request to ensure users are not vulnerable to CSRF. 
 * 
 * @since 4.4.0 
 * 
 * @global mixed          $wp_rest_auth_cookie 
 * @global WP_REST_Server $wp_rest_server      REST server instance. 
 * 
 * @param WP_Error|mixed $result Error from another authentication handler,  
 *                               null if we should handle it, or another value 
 *                               if not. 
 * @return WP_Error|mixed|bool WP_Error if the cookie is invalid, the $result, otherwise true. 
 */ 
function rest_cookie_check_errors( $result ) { 
  if ( ! empty( $result ) ) { 
      return $result; 
  } 
 
  global $wp_rest_auth_cookie, $wp_rest_server; 
 
  /** 
   * Is cookie authentication being used? (If we get an auth 
   * error, but we're still logged in, another authentication 
   * must have been used). 
   */ 
  if ( true !== $wp_rest_auth_cookie && is_user_logged_in() ) { 
      return $result; 
  } 
 
  // Determine if there is a nonce. 
  $nonce = null; 
 
  if ( isset( $_REQUEST['_wpnonce'] ) ) { 
      $nonce = $_REQUEST['_wpnonce']; 
  } elseif ( isset( $_SERVER['HTTP_X_WP_NONCE'] ) ) { 
      $nonce = $_SERVER['HTTP_X_WP_NONCE']; 
  } 
 
  if ( null === $nonce ) { 
      // No nonce at all, so act as if it's an unauthenticated request. 
      wp_set_current_user( 0 ); 
      return true; 
  } 
 
  // Check the nonce. 
  $result = wp_verify_nonce( $nonce, 'wp_rest' ); 
 
  if ( ! $result ) { 
      return new WP_Error( 'rest_cookie_invalid_nonce', __( 'Cookie nonce is invalid' ), array( 'status' => 403 ) ); 
  } 
 
  // Send a refreshed nonce in header. 
  $wp_rest_server->send_header( 'X-WP-Nonce', wp_create_nonce( 'wp_rest' ) ); 
 
  return true; 
} 
 
/** 
 * Collects cookie authentication status. 
 * 
 * Collects errors from wp_validate_auth_cookie for use by rest_cookie_check_errors. 
 * 
 * @since 4.4.0 
 * 
 * @see current_action() 
 * @global mixed $wp_rest_auth_cookie 
 */ 
function rest_cookie_collect_status() { 
  global $wp_rest_auth_cookie; 
 
  $status_type = current_action(); 
 
  if ( 'auth_cookie_valid' !== $status_type ) { 
      $wp_rest_auth_cookie = substr( $status_type, 12 ); 
      return; 
  } 
 
  $wp_rest_auth_cookie = true; 
} 
 
/** 
 * Parses an RFC3339 time into a Unix timestamp. 
 * 
 * @since 4.4.0 
 * 
 * @param string $date      RFC3339 timestamp. 
 * @param bool   $force_utc Optional. Whether to force UTC timezone instead of using 
 *                          the timestamp's timezone. Default false. 
 * @return int Unix timestamp. 
 */ 
function rest_parse_date( $date, $force_utc = false ) { 
  if ( $force_utc ) { 
      $date = preg_replace( '/[+-]\d+:?\d+$/', '+00:00', $date ); 
  } 
 
  $regex = '#^\d{4}-\d{2}-\d{2}[Tt ]\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:Z|[+-]\d{2}(?::\d{2})?)?$#'; 
 
  if ( ! preg_match( $regex, $date, $matches ) ) { 
      return false; 
  } 
 
  return strtotime( $date ); 
} 
 
/** 
 * Retrieves a local date with its GMT equivalent, in MySQL datetime format. 
 * 
 * @since 4.4.0 
 * 
 * @see rest_parse_date() 
 * 
 * @param string $date      RFC3339 timestamp. 
 * @param bool   $force_utc Whether a UTC timestamp should be forced. Default false. 
 * @return array|null Local and UTC datetime strings, in MySQL datetime format (Y-m-d H:i:s),  
 *                    null on failure. 
 */ 
function rest_get_date_with_gmt( $date, $force_utc = false ) { 
  $date = rest_parse_date( $date, $force_utc ); 
 
  if ( empty( $date ) ) { 
      return null; 
  } 
 
  $utc = date( 'Y-m-d H:i:s', $date ); 
  $local = get_date_from_gmt( $utc ); 
 
  return array( $local, $utc ); 
} 
 
/** 
 * Returns a contextual HTTP error code for authorization failure. 
 * 
 * @since 4.7.0 
 * 
 * @return integer 401 if the user is not logged in, 403 if the user is logged in. 
 */ 
function rest_authorization_required_code() { 
  return is_user_logged_in() ? 403 : 401; 
} 
 
/** 
 * Validate a request argument based on details registered to the route. 
 * 
 * @since 4.7.0 
 * 
 * @param  mixed            $value 
 * @param  WP_REST_Request  $request 
 * @param  string           $param 
 * @return WP_Error|boolean 
 */ 
function rest_validate_request_arg( $value, $request, $param ) { 
  $attributes = $request->get_attributes(); 
  if ( ! isset( $attributes['args'][ $param ] ) || ! is_array( $attributes['args'][ $param ] ) ) { 
      return true; 
  } 
  $args = $attributes['args'][ $param ]; 
 
  return rest_validate_value_from_schema( $value, $args, $param ); 
} 
 
/** 
 * Sanitize a request argument based on details registered to the route. 
 * 
 * @since 4.7.0 
 * 
 * @param  mixed            $value 
 * @param  WP_REST_Request  $request 
 * @param  string           $param 
 * @return mixed 
 */ 
function rest_sanitize_request_arg( $value, $request, $param ) { 
  $attributes = $request->get_attributes(); 
  if ( ! isset( $attributes['args'][ $param ] ) || ! is_array( $attributes['args'][ $param ] ) ) { 
      return $value; 
  } 
  $args = $attributes['args'][ $param ]; 
 
  return rest_sanitize_value_from_schema( $value, $args ); 
} 
 
/** 
 * Parse a request argument based on details registered to the route. 
 * 
 * Runs a validation check and sanitizes the value, primarily to be used via 
 * the `sanitize_callback` arguments in the endpoint args registration. 
 * 
 * @since 4.7.0 
 * 
 * @param  mixed            $value 
 * @param  WP_REST_Request  $request 
 * @param  string           $param 
 * @return mixed 
 */ 
function rest_parse_request_arg( $value, $request, $param ) { 
  $is_valid = rest_validate_request_arg( $value, $request, $param ); 
 
  if ( is_wp_error( $is_valid ) ) { 
      return $is_valid; 
  } 
 
  $value = rest_sanitize_request_arg( $value, $request, $param ); 
 
  return $value; 
} 
 
/** 
 * Determines if an IP address is valid. 
 * 
 * Handles both IPv4 and IPv6 addresses. 
 * 
 * @since 4.7.0 
 * 
 * @param  string $ip IP address. 
 * @return string|false The valid IP address, otherwise false. 
 */ 
function rest_is_ip_address( $ip ) { 
  $ipv4_pattern = '/^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.) {3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/'; 
 
  if ( ! preg_match( $ipv4_pattern, $ip ) && ! Requests_IPv6::check_ipv6( $ip ) ) { 
      return false; 
  } 
 
  return $ip; 
} 
 
/** 
 * Changes a boolean-like value into the proper boolean value. 
 * 
 * @since 4.7.0 
 * 
 * @param bool|string|int $value The value being evaluated. 
 * @return boolean Returns the proper associated boolean value. 
 */ 
function rest_sanitize_boolean( $value ) { 
  // String values are translated to `true`; make sure 'false' is false. 
  if ( is_string( $value ) ) { 
      $value = strtolower( $value ); 
      if ( in_array( $value, array( 'false', '0' ), true ) ) { 
          $value = false; 
      } 
  } 
 
  // Everything else will map nicely to boolean. 
  return (boolean) $value; 
} 
 
/** 
 * Determines if a given value is boolean-like. 
 * 
 * @since 4.7.0 
 * 
 * @param bool|string $maybe_bool The value being evaluated. 
 * @return boolean True if a boolean, otherwise false. 
 */ 
function rest_is_boolean( $maybe_bool ) { 
  if ( is_bool( $maybe_bool ) ) { 
      return true; 
  } 
 
  if ( is_string( $maybe_bool ) ) { 
      $maybe_bool = strtolower( $maybe_bool ); 
 
      $valid_boolean_values = array( 
          'false',  
          'true',  
          '0',  
          '1',  
 ); 
 
      return in_array( $maybe_bool, $valid_boolean_values, true ); 
  } 
 
  if ( is_int( $maybe_bool ) ) { 
      return in_array( $maybe_bool, array( 0, 1 ), true ); 
  } 
 
  return false; 
} 
 
/** 
 * Retrieves the avatar urls in various sizes based on a given email address. 
 * 
 * @since 4.7.0 
 * 
 * @see get_avatar_url() 
 * 
 * @param string $email Email address. 
 * @return array $urls Gravatar url for each size. 
 */ 
function rest_get_avatar_urls( $email ) { 
  $avatar_sizes = rest_get_avatar_sizes(); 
 
  $urls = array(); 
  foreach ( $avatar_sizes as $size ) { 
      $urls[ $size ] = get_avatar_url( $email, array( 'size' => $size ) ); 
  } 
 
  return $urls; 
} 
 
/** 
 * Retrieves the pixel sizes for avatars. 
 * 
 * @since 4.7.0 
 * 
 * @return array List of pixel sizes for avatars. Default `[ 24, 48, 96 ]`. 
 */ 
function rest_get_avatar_sizes() { 
  /** 
   * Filter the REST avatar sizes. 
   * 
   * Use this filter to adjust the array of sizes returned by the 
   * `rest_get_avatar_sizes` function. 
   * 
   * @since 4.4.0 
   * 
   * @param array $sizes An array of int values that are the pixel sizes for avatars. 
   *                     Default `[ 24, 48, 96 ]`. 
   */ 
  return apply_filters( 'rest_avatar_sizes', array( 24, 48, 96 ) ); 
} 
 
/** 
 * Validate a value based on a schema. 
 * 
 * @param mixed  $value The value to validate. 
 * @param array  $args  Schema array to use for validation. 
 * @param string $param The parameter name, used in error messages. 
 * @return true|WP_Error 
 */ 
function rest_validate_value_from_schema( $value, $args, $param = '' ) { 
  if ( 'array' === $args['type'] ) { 
      if ( ! is_array( $value ) ) { 
          $value = preg_split( '/[\s, ]+/', $value ); 
      } 
      if ( ! wp_is_numeric_array( $value ) ) { 
          /** translators: 1: parameter, 2: type name */ 
          return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s is not of type %2$s.' ), $param, 'array' ) ); 
      } 
      foreach ( $value as $index => $v ) { 
          $is_valid = rest_validate_value_from_schema( $v, $args['items'], $param . '[' . $index . ']' ); 
          if ( is_wp_error( $is_valid ) ) { 
              return $is_valid; 
          } 
      } 
  } 
  if ( ! empty( $args['enum'] ) ) { 
      if ( ! in_array( $value, $args['enum'], true ) ) { 
          /** translators: 1: parameter, 2: list of valid values */ 
          return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s is not one of %2$s.' ), $param, implode( ', ', $args['enum'] ) ) ); 
      } 
  } 
 
  if ( in_array( $args['type'], array( 'integer', 'number' ) ) && ! is_numeric( $value ) ) { 
      /** translators: 1: parameter, 2: type name */ 
      return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s is not of type %2$s.' ), $param, $args['type'] ) ); 
  } 
 
  if ( 'integer' === $args['type'] && round( floatval( $value ) ) !== floatval( $value ) ) { 
      /** translators: 1: parameter, 2: type name */ 
      return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s is not of type %2$s.' ), $param, 'integer' ) ); 
  } 
 
  if ( 'boolean' === $args['type'] && ! rest_is_boolean( $value ) ) { 
      /** translators: 1: parameter, 2: type name */ 
      return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s is not of type %2$s.' ), $value, 'boolean' ) ); 
  } 
 
  if ( 'string' === $args['type'] && ! is_string( $value ) ) { 
      /** translators: 1: parameter, 2: type name */ 
      return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s is not of type %2$s.' ), $param, 'string' ) ); 
  } 
 
  if ( isset( $args['format'] ) ) { 
      switch ( $args['format'] ) { 
          case 'date-time' : 
              if ( ! rest_parse_date( $value ) ) { 
                  return new WP_Error( 'rest_invalid_date', __( 'Invalid date.' ) ); 
              } 
              break; 
 
          case 'email' : 
              // is_email() checks for 3 characters (a@b), but 
              // wp_handle_comment_submission() requires 6 characters (a@b.co) 
              // 
              // https://core.trac.wordpress.org/ticket/38506 
              if ( ! is_email( $value ) || strlen( $value ) < 6 ) { 
                  return new WP_Error( 'rest_invalid_email', __( 'Invalid email address.' ) ); 
              } 
              break; 
          case 'ip' : 
              if ( ! rest_is_ip_address( $value ) ) { 
                  /** translators: %s: IP address */ 
                  return new WP_Error( 'rest_invalid_param', sprintf( __( '%s is not a valid IP address.' ), $value ) ); 
              } 
              break; 
      } 
  } 
 
  if ( in_array( $args['type'], array( 'number', 'integer' ), true ) && ( isset( $args['minimum'] ) || isset( $args['maximum'] ) ) ) { 
      if ( isset( $args['minimum'] ) && ! isset( $args['maximum'] ) ) { 
          if ( ! empty( $args['exclusiveMinimum'] ) && $value <= $args['minimum'] ) { 
              /** translators: 1: parameter, 2: minimum number */ 
              return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be greater than %2$d (exclusive)' ), $param, $args['minimum'] ) ); 
          } elseif ( empty( $args['exclusiveMinimum'] ) && $value < $args['minimum'] ) { 
              /** translators: 1: parameter, 2: minimum number */ 
              return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be greater than %2$d (inclusive)' ), $param, $args['minimum'] ) ); 
          } 
      } elseif ( isset( $args['maximum'] ) && ! isset( $args['minimum'] ) ) { 
          if ( ! empty( $args['exclusiveMaximum'] ) && $value >= $args['maximum'] ) { 
              /** translators: 1: parameter, 2: maximum number */ 
              return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be less than %2$d (exclusive)' ), $param, $args['maximum'] ) ); 
          } elseif ( empty( $args['exclusiveMaximum'] ) && $value > $args['maximum'] ) { 
              /** translators: 1: parameter, 2: maximum number */ 
              return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be less than %2$d (inclusive)' ), $param, $args['maximum'] ) ); 
          } 
      } elseif ( isset( $args['maximum'] ) && isset( $args['minimum'] ) ) { 
          if ( ! empty( $args['exclusiveMinimum'] ) && ! empty( $args['exclusiveMaximum'] ) ) { 
              if ( $value >= $args['maximum'] || $value <= $args['minimum'] ) { 
                  /** translators: 1: parameter, 2: minimum number, 3: maximum number */ 
                  return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be between %2$d (exclusive) and %3$d (exclusive)' ), $param, $args['minimum'], $args['maximum'] ) ); 
              } 
          } elseif ( empty( $args['exclusiveMinimum'] ) && ! empty( $args['exclusiveMaximum'] ) ) { 
              if ( $value >= $args['maximum'] || $value < $args['minimum'] ) { 
                  /** translators: 1: parameter, 2: minimum number, 3: maximum number */ 
                  return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be between %2$d (inclusive) and %3$d (exclusive)' ), $param, $args['minimum'], $args['maximum'] ) ); 
              } 
          } elseif ( ! empty( $args['exclusiveMinimum'] ) && empty( $args['exclusiveMaximum'] ) ) { 
              if ( $value > $args['maximum'] || $value <= $args['minimum'] ) { 
                  /** translators: 1: parameter, 2: minimum number, 3: maximum number */ 
                  return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be between %2$d (exclusive) and %3$d (inclusive)' ), $param, $args['minimum'], $args['maximum'] ) ); 
              } 
          } elseif ( empty( $args['exclusiveMinimum'] ) && empty( $args['exclusiveMaximum'] ) ) { 
              if ( $value > $args['maximum'] || $value < $args['minimum'] ) { 
                  /** translators: 1: parameter, 2: minimum number, 3: maximum number */ 
                  return new WP_Error( 'rest_invalid_param', sprintf( __( '%1$s must be between %2$d (inclusive) and %3$d (inclusive)' ), $param, $args['minimum'], $args['maximum'] ) ); 
              } 
          } 
      } 
  } 
 
  return true; 
} 
 
/** 
 * Sanitize a value based on a schema. 
 * 
 * @param mixed $value The value to sanitize. 
 * @param array $args  Schema array to use for sanitization. 
 * @return true|WP_Error 
 */ 
function rest_sanitize_value_from_schema( $value, $args ) { 
  if ( 'array' === $args['type'] ) { 
      if ( empty( $args['items'] ) ) { 
          return (array) $value; 
      } 
      if ( ! is_array( $value ) ) { 
          $value = preg_split( '/[\s, ]+/', $value ); 
      } 
      foreach ( $value as $index => $v ) { 
          $value[ $index ] = rest_sanitize_value_from_schema( $v, $args['items'] ); 
      } 
      // Normalize to numeric array so nothing unexpected 
      // is in the keys. 
      $value = array_values( $value ); 
      return $value; 
  } 
  if ( 'integer' === $args['type'] ) { 
      return (int) $value; 
  } 
 
  if ( 'number' === $args['type'] ) { 
      return (float) $value; 
  } 
 
  if ( 'boolean' === $args['type'] ) { 
      return rest_sanitize_boolean( $value ); 
  } 
 
  if ( isset( $args['format'] ) ) { 
      switch ( $args['format'] ) { 
          case 'date-time' : 
              return sanitize_text_field( $value ); 
 
          case 'email' : 
              /** 
               * sanitize_email() validates, which would be unexpected. 
               */ 
              return sanitize_text_field( $value ); 
 
          case 'uri' : 
              return esc_url_raw( $value ); 
 
          case 'ip' : 
              return sanitize_text_field( $value ); 
      } 
  } 
 
  if ( 'string' === $args['type'] ) { 
      return strval( $value ); 
  } 
 
  return $value; 
}