Block Editor: Preload wp/v2/media with OPTIONS for caps check.

Also introduces a `block_editor_preload_paths` filter for plugins and themes to preload additional data.

Merges [43833] from the 5.0 branch to trunk.

Props imath, mattheu, danielbachhuber.
Fixes #45194.



git-svn-id: https://develop.svn.wordpress.org/trunk@44172 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/edit-form-blocks.php

@@ -49,8 +49,21 @@ $preload_paths = array(
 	sprintf( '/wp/v2/%s/%s?context=edit', $rest_base, $post->ID ),
 	sprintf( '/wp/v2/types/%s?context=edit', $post_type ),
 	sprintf( '/wp/v2/users/me?post_type=%s&context=edit', $post_type ),
+	array( '/wp/v2/media', 'OPTIONS' ),
 );
 
+/**
+ * Preload common data by specifying an array of REST API paths that will be preloaded.
+ *
+ * Filters the array of paths that will be preloaded.
+ *
+ * @since 5.0.0
+ *
+ * @param array  $preload_paths Array of paths to preload.
+ * @param object $post          The post resource data.
+ */
+$preload_paths = apply_filters( 'block_editor_preload_paths', $preload_paths, $post );
+
 /*
  * Ensure the global $post remains the same after API data is preloaded.
  * Because API preloading can call the_content and other filters, plugins

src/wp-includes/rest-api.php

@@ -1342,12 +1342,22 @@ function rest_preload_api_request( $memo, $path ) {
 		return $memo;
 	}
 
+	$method = 'GET';
+	if ( is_array( $path ) && 2 === count( $path ) ) {
+		$method = end( $path );
+		$path   = reset( $path );
+
+		if ( ! in_array( $method, array( 'GET', 'OPTIONS' ), true ) ) {
+			$method = 'GET';
+		}
+	}
+
 	$path_parts = parse_url( $path );
 	if ( false === $path_parts ) {
 		return $memo;
 	}
 
-	$request = new WP_REST_Request( 'GET', $path_parts['path'] );
+	$request = new WP_REST_Request( $method, $path_parts['path'] );
 	if ( ! empty( $path_parts['query'] ) ) {
 		parse_str( $path_parts['query'], $query_params );
 		$request->set_query_params( $query_params );
@@ -1366,10 +1376,19 @@ function rest_preload_api_request( $memo, $path ) {
 			$data['_links'] = $links;
 		}
 
-		$memo[ $path ] = array(
+		if ( 'OPTIONS' === $method ) {
-			'body'    => $data,
+			$response = rest_send_allow_header( $response, $server, $request );
-			'headers' => $response->headers,
+
-		);
+			$memo[ $method ][ $path ] = array(
+				'body'    => $data,
+				'headers' => $response->headers,
+			);
+		} else {
+			$memo[ $path ] = array(
+				'body'    => $data,
+				'headers' => $response->headers,
+			);
+		}
 	}
 
 	return $memo;

tests/phpunit/tests/rest-api.php

@@ -721,4 +721,25 @@ class Tests_REST_API extends WP_UnitTestCase {
 	function test_rest_preload_api_request_no_notices_php_52() {
 		$this->assertTrue( is_array( rest_preload_api_request( 0, '/' ) ) );
 	}
+
+	function test_rest_preload_api_request_with_method() {
+		$rest_server               = $GLOBALS['wp_rest_server'];
+		$GLOBALS['wp_rest_server'] = null;
+
+		$preload_paths = array(
+			'/wp/v2/types',
+			array( '/wp/v2/media', 'OPTIONS' ),
+		);
+
+		$preload_data = array_reduce(
+			$preload_paths,
+			'rest_preload_api_request',
+			array()
+		);
+
+		$this->assertSame( array_keys( $preload_data ), array( '/wp/v2/types', 'OPTIONS' ) );
+		$this->assertTrue( isset( $preload_data['OPTIONS']['/wp/v2/media'] ) );
+
+		$GLOBALS['wp_rest_server'] = $rest_server;
+	}
 }