REST API: Introduce Autosaves controller and endpoint.

- Adds `WP_REST_Autosaves_Controller` which extends `WP_REST_Revisions_Controller`.
- Autosaves endpoint is registered for all post types except attachment because even post types without revisions enabled are expected to autosave.
- Because setting the `DOING_AUTOSAVE` constant pollutes the test suite, autosaves tests are run last. We may want to improve upon this later. 

Also, use a truly impossibly high number in User Controller tests. The number `100`, (or `7777` in `trunk`), could be valid in certain test run configurations. The `REST_TESTS_IMPOSSIBLY_HIGH_NUMBER` constant is impossibly high for this very reason.

Finally, Skip Autosaves controller test for multisite. There's a PHP 5.2 edge case where paths calculated differently, possibly caused by differing version of PHPUnit.

Props adamsilverstein, aduth, azaozz, danielbachhuber, rmccue, danielbachhuber.

Merges [43767], [43768], [43769] to trunk.

See #45132, #45131.
Fixes #45128, #43316.
Built from https://develop.svn.wordpress.org/trunk@44126


git-svn-id: http://core.svn.wordpress.org/trunk@43956 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/rest-api.php

@@ -193,6 +193,11 @@ function create_initial_rest_routes() {
 			$revisions_controller = new WP_REST_Revisions_Controller( $post_type->name );
 			$revisions_controller->register_routes();
 		}
+
+		if ( 'attachment' !== $post_type->name ) {
+			$autosaves_controller = new WP_REST_Autosaves_Controller( $post_type->name );
+			$autosaves_controller->register_routes();
+		}
 	}
 
 	// Post types.

wp-includes/rest-api/endpoints/class-wp-rest-autosaves-controller.php

@@ -0,0 +1,392 @@
+<?php
+/**
+ * REST API: WP_REST_Autosaves_Controller class.
+ *
+ * @package WordPress
+ * @subpackage REST_API
+ * @since 5.0.0
+ */
+
+/**
+ * Core class used to access autosaves via the REST API.
+ *
+ * @since 5.0.0
+ *
+ * @see WP_REST_Controller
+ */
+class WP_REST_Autosaves_Controller extends WP_REST_Revisions_Controller {
+
+	/**
+	 * Parent post type.
+	 *
+	 * @since 5.0.0
+	 * @var string
+	 */
+	private $parent_post_type;
+
+	/**
+	 * Parent post controller.
+	 *
+	 * @since 5.0.0
+	 * @var WP_REST_Controller
+	 */
+	private $parent_controller;
+
+	/**
+	 * Revision controller.
+	 *
+	 * @since 5.0.0
+	 * @var WP_REST_Controller
+	 */
+	private $revisions_controller;
+
+	/**
+	 * The base of the parent controller's route.
+	 *
+	 * @since 5.0.0
+	 * @var string
+	 */
+	private $parent_base;
+
+	/**
+	 * Constructor.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param string $parent_post_type Post type of the parent.
+	 */
+	public function __construct( $parent_post_type ) {
+		$this->parent_post_type = $parent_post_type;
+		$post_type_object       = get_post_type_object( $parent_post_type );
+
+		// Ensure that post type-specific controller logic is available.
+		$parent_controller_class = ! empty( $post_type_object->rest_controller_class ) ? $post_type_object->rest_controller_class : 'WP_REST_Posts_Controller';
+
+		$this->parent_controller    = new $parent_controller_class( $post_type_object->name );
+		$this->revisions_controller = new WP_REST_Revisions_Controller( $parent_post_type );
+		$this->rest_namespace       = 'wp/v2';
+		$this->rest_base            = 'autosaves';
+		$this->parent_base          = ! empty( $post_type_object->rest_base ) ? $post_type_object->rest_base : $post_type_object->name;
+	}
+
+	/**
+	 * Registers routes for autosaves.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @see register_rest_route()
+	 */
+	public function register_routes() {
+		register_rest_route(
+			$this->rest_namespace,
+			'/' . $this->parent_base . '/(?P<parent>[\d]+)/' . $this->rest_base,
+			array(
+				'args'   => array(
+					'parent' => array(
+						'description' => __( 'The ID for the parent of the object.' ),
+						'type'        => 'integer',
+					),
+				),
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_items' ),
+					'permission_callback' => array( $this->revisions_controller, 'get_items_permissions_check' ),
+					'args'                => $this->get_collection_params(),
+				),
+				array(
+					'methods'             => WP_REST_Server::CREATABLE,
+					'callback'            => array( $this, 'create_item' ),
+					'permission_callback' => array( $this, 'create_item_permissions_check' ),
+					'args'                => $this->get_endpoint_args_for_item_schema( WP_REST_Server::CREATABLE ),
+				),
+				'schema' => array( $this, 'get_public_item_schema' ),
+			)
+		);
+
+		register_rest_route(
+			$this->rest_namespace,
+			'/' . $this->parent_base . '/(?P<parent>[\d]+)/' . $this->rest_base . '/(?P<id>[\d]+)',
+			array(
+				'args'   => array(
+					'parent' => array(
+						'description' => __( 'The ID for the parent of the object.' ),
+						'type'        => 'integer',
+					),
+					'id'     => array(
+						'description' => __( 'The ID for the object.' ),
+						'type'        => 'integer',
+					),
+				),
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_item' ),
+					'permission_callback' => array( $this->revisions_controller, 'get_item_permissions_check' ),
+					'args'                => array(
+						'context' => $this->get_context_param( array( 'default' => 'view' ) ),
+					),
+				),
+				'schema' => array( $this, 'get_public_item_schema' ),
+			)
+		);
+
+	}
+
+	/**
+	 * Get the parent post.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param int $parent_id Supplied ID.
+	 * @return WP_Post|WP_Error Post object if ID is valid, WP_Error otherwise.
+	 */
+	protected function get_parent( $parent_id ) {
+		return $this->revisions_controller->get_parent( $parent_id );
+	}
+
+	/**
+	 * Checks if a given request has access to create an autosave revision.
+	 *
+	 * Autosave revisions inherit permissions from the parent post,
+	 * check if the current user has permission to edit the post.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return true|WP_Error True if the request has access to create the item, WP_Error object otherwise.
+	 */
+	public function create_item_permissions_check( $request ) {
+		$id = $request->get_param( 'id' );
+		if ( empty( $id ) ) {
+			return new WP_Error( 'rest_post_invalid_id', __( 'Invalid item ID.' ), array( 'status' => 404 ) );
+		}
+
+		return $this->parent_controller->update_item_permissions_check( $request );
+	}
+
+	/**
+	 * Creates, updates or deletes an autosave revision.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 */
+	public function create_item( $request ) {
+
+		if ( ! defined( 'DOING_AUTOSAVE' ) ) {
+			define( 'DOING_AUTOSAVE', true );
+		}
+
+		$post = get_post( $request->get_param( 'id' ) );
+
+		if ( is_wp_error( $post ) ) {
+			return $post;
+		}
+
+		$prepared_post     = $this->parent_controller->prepare_item_for_database( $request );
+		$prepared_post->ID = $post->ID;
+		$user_id           = get_current_user_id();
+
+		if ( ( 'draft' === $post->post_status || 'auto-draft' === $post->post_status ) && $post->post_author == $user_id ) {
+			// Draft posts for the same author: autosaving updates the post and does not create a revision.
+			// Convert the post object to an array and add slashes, wp_update_post expects escaped array.
+			$autosave_id = wp_update_post( wp_slash( (array) $prepared_post ), true );
+		} else {
+			// Non-draft posts: create or update the post autosave.
+			$autosave_id = $this->create_post_autosave( (array) $prepared_post );
+		}
+
+		if ( is_wp_error( $autosave_id ) ) {
+			return $autosave_id;
+		}
+
+		$autosave = get_post( $autosave_id );
+		$request->set_param( 'context', 'edit' );
+
+		$response = $this->prepare_item_for_response( $autosave, $request );
+		$response = rest_ensure_response( $response );
+
+		return $response;
+	}
+
+	/**
+	 * Get the autosave, if the ID is valid.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param WP_REST_Request $request Full data about the request.
+	 * @return WP_Post|WP_Error Revision post object if ID is valid, WP_Error otherwise.
+	 */
+	public function get_item( $request ) {
+		$parent_id = (int) $request->get_param( 'parent' );
+
+		if ( $parent_id <= 0 ) {
+			return new WP_Error( 'rest_post_invalid_id', __( 'Invalid parent post ID.' ), array( 'status' => 404 ) );
+		}
+
+		$autosave = wp_get_post_autosave( $parent_id );
+
+		if ( ! $autosave ) {
+			return new WP_Error( 'rest_post_no_autosave', __( 'There is no autosave revision for this post.' ), array( 'status' => 404 ) );
+		}
+
+		$response = $this->prepare_item_for_response( $autosave, $request );
+		return $response;
+	}
+
+	/**
+	 * Gets a collection of autosaves using wp_get_post_autosave.
+	 *
+	 * Contains the user's autosave, for empty if it doesn't exist.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param WP_REST_Request $request Full data about the request.
+	 * @return WP_REST_Response|WP_Error Response object on success, or WP_Error object on failure.
+	 */
+	public function get_items( $request ) {
+		$parent = $this->get_parent( $request->get_param( 'parent' ) );
+		if ( is_wp_error( $parent ) ) {
+			return $parent;
+		}
+
+		$response  = array();
+		$parent_id = $parent->ID;
+		$revisions = wp_get_post_revisions( $parent_id, array( 'check_enabled' => false ) );
+
+		foreach ( $revisions as $revision ) {
+			if ( false !== strpos( $revision->post_name, "{$parent_id}-autosave" ) ) {
+				$data       = $this->prepare_item_for_response( $revision, $request );
+				$response[] = $this->prepare_response_for_collection( $data );
+			}
+		}
+
+		return rest_ensure_response( $response );
+	}
+
+
+	/**
+	 * Retrieves the autosave's schema, conforming to JSON Schema.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @return array Item schema data.
+	 */
+	public function get_item_schema() {
+		$schema = $this->revisions_controller->get_item_schema();
+
+		$schema['properties']['preview_link'] = array(
+			'description' => __( 'Preview link for the post.' ),
+			'type'        => 'string',
+			'format'      => 'uri',
+			'context'     => array( 'edit' ),
+			'readonly'    => true,
+		);
+
+		return $schema;
+	}
+
+	/**
+	 * Creates autosave for the specified post.
+	 *
+	 * From wp-admin/post.php.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param mixed $post_data Associative array containing the post data.
+	 * @return mixed The autosave revision ID or WP_Error.
+	 */
+	public function create_post_autosave( $post_data ) {
+
+		$post_id = (int) $post_data['ID'];
+		$post    = get_post( $post_id );
+
+		if ( is_wp_error( $post ) ) {
+			return $post;
+		}
+
+		$user_id = get_current_user_id();
+
+		// Store one autosave per author. If there is already an autosave, overwrite it.
+		$old_autosave = wp_get_post_autosave( $post_id, $user_id );
+
+		if ( $old_autosave ) {
+			$new_autosave                = _wp_post_revision_data( $post_data, true );
+			$new_autosave['ID']          = $old_autosave->ID;
+			$new_autosave['post_author'] = $user_id;
+
+			// If the new autosave has the same content as the post, delete the autosave.
+			$autosave_is_different = false;
+
+			foreach ( array_intersect( array_keys( $new_autosave ), array_keys( _wp_post_revision_fields( $post ) ) ) as $field ) {
+				if ( normalize_whitespace( $new_autosave[ $field ] ) != normalize_whitespace( $post->$field ) ) {
+					$autosave_is_different = true;
+					break;
+				}
+			}
+
+			if ( ! $autosave_is_different ) {
+				wp_delete_post_revision( $old_autosave->ID );
+				return new WP_Error( 'rest_autosave_no_changes', __( 'There is nothing to save. The autosave and the post content are the same.' ), array( 'status' => 400 ) );
+			}
+
+			/**
+			 * This filter is documented in wp-admin/post.php.
+			 */
+			do_action( 'wp_creating_autosave', $new_autosave );
+
+			// wp_update_post expects escaped array.
+			return wp_update_post( wp_slash( $new_autosave ) );
+		}
+
+		// Create the new autosave as a special post revision.
+		return _wp_put_post_revision( $post_data, true );
+	}
+
+	/**
+	 * Prepares the revision for the REST response.
+	 *
+	 * @since 5.0.0
+	 *
+	 * @param WP_Post         $post    Post revision object.
+	 * @param WP_REST_Request $request Request object.
+	 *
+	 * @return WP_REST_Response Response object.
+	 */
+	public function prepare_item_for_response( $post, $request ) {
+
+		$response = $this->revisions_controller->prepare_item_for_response( $post, $request );
+
+		$fields = $this->get_fields_for_response( $request );
+
+		if ( in_array( 'preview_link', $fields, true ) ) {
+			$parent_id          = wp_is_post_autosave( $post );
+			$preview_post_id    = false === $parent_id ? $post->ID : $parent_id;
+			$preview_query_args = array();
+
+			if ( false !== $parent_id ) {
+				$preview_query_args['preview_id']    = $parent_id;
+				$preview_query_args['preview_nonce'] = wp_create_nonce( 'post_preview_' . $parent_id );
+			}
+
+			$response->data['preview_link'] = get_preview_post_link( $preview_post_id, $preview_query_args );
+		}
+
+		$context        = ! empty( $request['context'] ) ? $request['context'] : 'view';
+		$response->data = $this->add_additional_fields_to_object( $response->data, $request );
+		$response->data = $this->filter_response_by_context( $response->data, $context );
+
+		/**
+		 * Filters a revision returned from the API.
+		 *
+		 * Allows modification of the revision right before it is returned.
+		 *
+		 * @since 5.0.0
+		 *
+		 * @param WP_REST_Response $response The response object.
+		 * @param WP_Post          $post     The original revision object.
+		 * @param WP_REST_Request  $request  Request used to generate the response.
+		 */
+		return apply_filters( 'rest_prepare_autosave', $response, $post, $request );
+	}
+}

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.1-alpha-44125';
+$wp_version = '5.1-alpha-44126';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.

wp-settings.php

@@ -230,6 +230,7 @@ require( ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-attachments-contro
 require( ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-post-types-controller.php' );
 require( ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-post-statuses-controller.php' );
 require( ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-revisions-controller.php' );
+require( ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-autosaves-controller.php' );
 require( ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-taxonomies-controller.php' );
 require( ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-terms-controller.php' );
 require( ABSPATH . WPINC . '/rest-api/endpoints/class-wp-rest-users-controller.php' );