REST API: Allow unsetting of page templates in update requests.

Sending a request to update a page with the template property set to an empty string resulted in an error because “” was not a valid value in the enum.

Props lucasstark, swissspidy.
Fixes #38877.

git-svn-id: https://develop.svn.wordpress.org/trunk@39343 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/rest-api/endpoints/class-wp-rest-posts-controller.php

@@ -1928,7 +1928,7 @@ class WP_REST_Posts_Controller extends WP_REST_Controller {
 		$schema['properties']['template'] = array(
 			'description' => __( 'The theme file to use to display the object.' ),
 			'type'        => 'string',
-			'enum'        => array_keys( wp_get_theme()->get_page_templates( null, $this->post_type ) ),
+			'enum'        => array_merge( array_keys( wp_get_theme()->get_page_templates( null, $this->post_type ) ), array( '' ) ),
 			'context'     => array( 'view', 'edit' ),
 		);
 

tests/phpunit/includes/spy-rest-server.php

@@ -5,6 +5,7 @@ class Spy_REST_Server extends WP_REST_Server {
 	public $sent_headers = array();
 	public $sent_body = '';
 	public $last_request = null;
+	public $override_by_default = false;
 
 	/**
 	 * Get the raw $endpoints data from the server
@@ -41,6 +42,20 @@ class Spy_REST_Server extends WP_REST_Server {
 		return parent::dispatch( $request );
 	}
 
+	/**
+	 * Override the register_route method so we can re-register routes internally if needed.
+	 *
+	 * @param string $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. Also set $GLOBALS['wp_rest_server']->override_by_default = true
+	 *                           to set overrides when you don't have access to the caller context.
+	 */
+	public function register_route( $namespace, $route, $route_args, $override = false ) {
+		parent::register_route( $namespace, $route, $route_args, $override || $this->override_by_default );
+	}
+
 	public function serve_request( $path = null ) {
 
 		ob_start();

tests/phpunit/tests/rest-api/rest-pages-controller.php

@@ -27,6 +27,11 @@ class WP_Test_REST_Pages_Controller extends WP_Test_REST_Post_Type_Controller_Te
 		parent::setUp();
 		$this->has_setup_template = false;
 		add_filter( 'theme_page_templates', array( $this, 'filter_theme_page_templates' ) );
+		// reregister the route as we now have a template available.
+		$GLOBALS['wp_rest_server']->override_by_default = true;
+		$controller = new WP_REST_Posts_Controller( 'page' );
+		$controller->register_routes();
+		$GLOBALS['wp_rest_server']->override_by_default = false;
 	}
 
 	public function test_register_routes() {

tests/phpunit/tests/rest-api/rest-posts-controller.php

@@ -1032,6 +1032,12 @@ class WP_Test_REST_Posts_Controller extends WP_Test_REST_Post_Type_Controller_Te
 		wp_set_current_user( self::$editor_id );
 		add_filter( 'theme_post_templates', array( $this, 'filter_theme_post_templates' ) );
 
+		// reregister the route as we now have a template available.
+		$GLOBALS['wp_rest_server']->override_by_default = true;
+		$controller = new WP_REST_Posts_Controller( 'post' );
+		$controller->register_routes();
+		$GLOBALS['wp_rest_server']->override_by_default = false;
+
 		$request = new WP_REST_Request( 'POST', '/wp/v2/posts' );
 		$params = $this->set_post_data( array(
 			'template' => 'post-my-test-template.php',
@@ -1061,6 +1067,24 @@ class WP_Test_REST_Posts_Controller extends WP_Test_REST_Post_Type_Controller_Te
 		$request->set_body_params( $params );
 		$response = $this->server->dispatch( $request );
 
+		$this->assertErrorResponse( 'rest_invalid_param', $response, 400 );
+	}
+
+	/**
+	 * @ticket 38877
+	 */
+	public function test_create_item_with_template_none() {
+		wp_set_current_user( self::$editor_id );
+		add_filter( 'theme_post_templates', array( $this, 'filter_theme_post_templates' ) );
+		update_post_meta( self::$post_id, '_wp_page_template', 'post-my-test-template.php' );
+
+		$request = new WP_REST_Request( 'PUT', sprintf( '/wp/v2/posts/%d', self::$post_id ) );
+		$params = $this->set_post_data( array(
+			'template' => '',
+		) );
+		$request->set_body_params( $params );
+		$response = $this->server->dispatch( $request );
+
 		$data = $response->get_data();
 		$post_template = get_page_template_slug( get_post( $data['id'] ) );
 
@@ -2055,6 +2079,62 @@ class WP_Test_REST_Posts_Controller extends WP_Test_REST_Post_Type_Controller_Te
 		$this->assertErrorResponse( 'rest_cannot_assign_term', $response, 403 );
 	}
 
+	/**
+	 * @ticket 38698
+	 */
+	public function test_update_item_with_template() {
+		wp_set_current_user( self::$editor_id );
+		add_filter( 'theme_post_templates', array( $this, 'filter_theme_post_templates' ) );
+
+		// reregister the route as we now have a template available.
+		$GLOBALS['wp_rest_server']->override_by_default = true;
+		$controller = new WP_REST_Posts_Controller( 'post' );
+		$controller->register_routes();
+		$GLOBALS['wp_rest_server']->override_by_default = false;
+
+		$request = new WP_REST_Request( 'PUT', sprintf( '/wp/v2/posts/%d', self::$post_id ) );
+		$params = $this->set_post_data( array(
+			'template' => 'post-my-test-template.php',
+		) );
+		$request->set_body_params( $params );
+		$response = $this->server->dispatch( $request );
+
+		$data = $response->get_data();
+		$post_template = get_page_template_slug( get_post( $data['id'] ) );
+
+		$this->assertEquals( 'post-my-test-template.php', $data['template'] );
+		$this->assertEquals( 'post-my-test-template.php', $post_template );
+	}
+
+	/**
+	 * @ticket 38877
+	 */
+	public function test_update_item_with_template_none() {
+		wp_set_current_user( self::$editor_id );
+		add_filter( 'theme_post_templates', array( $this, 'filter_theme_post_templates' ) );
+		update_post_meta( self::$post_id, '_wp_page_template', 'post-my-test-template.php' );
+
+		// reregister the route as we now have a template available.
+		$GLOBALS['wp_rest_server']->override_by_default = true;
+		$controller = new WP_REST_Posts_Controller( 'post' );
+		$controller->register_routes();
+		$GLOBALS['wp_rest_server']->override_by_default = false;
+
+		$request = new WP_REST_Request( 'PUT', sprintf( '/wp/v2/posts/%d', self::$post_id ) );
+		$params = $this->set_post_data( array(
+			'template' => '',
+		) );
+		$request->set_body_params( $params );
+		$response = $this->server->dispatch( $request );
+
+		$data = $response->get_data();
+		$post_template = get_page_template_slug( get_post( $data['id'] ) );
+
+		$this->assertEquals( '', $data['template'] );
+		$this->assertEquals( '', $post_template );
+	}
+
+
 	public function verify_post_roundtrip( $input = array(), $expected_output = array() ) {
 		// Create the post
 		$request = new WP_REST_Request( 'POST', '/wp/v2/posts' );