From e4df8c04b10e95aedac80bdc9d9195f1c0db58e6 Mon Sep 17 00:00:00 2001 From: "K. Adam White" Date: Wed, 4 Oct 2017 18:44:41 +0000 Subject: [PATCH] REST API: Add _fields parameter to selectively include fields in response JSON. Allows REST API consumers to specify the specific fields needed in their application code, whitelisting those fields and omitting all others from the returned JSON response object. This permits applications that only need for example the ID and title of posts to avoid having to transfer the entire rendered post content over the wire alongside the desired fields. While this whitelisting has no affect on the queries run when preparing the response, it can yield significant reductions in the bandwidth required to transfer a response payload for simple applications. Props adamsilverstein, TimothyBlynJacobs, svrooij. Fixes #38131. git-svn-id: https://develop.svn.wordpress.org/trunk@41744 602fd350-edb4-49c9-b593-d223f7449a82 --- src/wp-includes/rest-api.php | 44 +++++++++++ tests/phpunit/tests/rest-api.php | 125 +++++++++++++++++++++++++++++++ 2 files changed, 169 insertions(+) diff --git a/src/wp-includes/rest-api.php b/src/wp-includes/rest-api.php index 34e1c591f6..697a7cc64b 100644 --- a/src/wp-includes/rest-api.php +++ b/src/wp-includes/rest-api.php @@ -165,6 +165,7 @@ function rest_api_default_filters() { // 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_post_dispatch', 'rest_filter_response_fields', 10, 3 ); add_filter( 'rest_pre_dispatch', 'rest_handle_options_request', 10, 3 ); } @@ -632,6 +633,49 @@ function rest_send_allow_header( $response, $server, $request ) { return $response; } +/** + * Filter the API response to include only a white-listed set of response object fields. + * + * @since 4.8.0 + * + * @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, trimmed down to contain a subset of fields. + */ +function rest_filter_response_fields( $response, $server, $request ) { + if ( ! isset( $request['_fields'] ) || $response->is_error() ) { + return $response; + } + + $data = $response->get_data(); + + $fields = is_array( $request['_fields'] ) ? $request['_fields'] : preg_split( '/[\s,]+/', $request['_fields'] ); + + if ( 0 === count( $fields ) ) { + return $response; + } + + // Trim off outside whitespace from the comma delimited list. + $fields = array_map( 'trim', $fields ); + + $fields_as_keyed = array_combine( $fields, array_fill( 0, count( $fields ), true ) ); + + if ( wp_is_numeric_array( $data ) ) { + $new_data = array(); + foreach ( $data as $item ) { + $new_data[] = array_intersect_key( $item, $fields_as_keyed ); + } + } else { + $new_data = array_intersect_key( $data, $fields_as_keyed ); + } + + $response->set_data( $new_data ); + + return $response; +} + /** * Adds the REST API URL to the WP RSD endpoint. * diff --git a/tests/phpunit/tests/rest-api.php b/tests/phpunit/tests/rest-api.php index 90a480d641..45c1ccef71 100644 --- a/tests/phpunit/tests/rest-api.php +++ b/tests/phpunit/tests/rest-api.php @@ -304,6 +304,131 @@ class Tests_REST_API extends WP_UnitTestCase { $this->assertNull( $response ); } + /** + * Ensure that result fields are not whitelisted if no request['_fields'] is present. + */ + public function test_rest_filter_response_fields_no_request_filter() { + $response = new WP_REST_Response(); + $response->set_data( array( 'a' => true ) ); + $request = array(); + + $response = rest_filter_response_fields( $response, null, $request ); + $this->assertEquals( array( 'a' => true ), $response->get_data() ); + } + + /** + * Ensure that result fields are whitelisted if request['_fields'] is present. + */ + public function test_rest_filter_response_fields_single_field_filter() { + $response = new WP_REST_Response(); + $response->set_data( array( + 'a' => 0, + 'b' => 1, + 'c' => 2, + ) ); + $request = array( + '_fields' => 'b' + ); + + $response = rest_filter_response_fields( $response, null, $request ); + $this->assertEquals( array( 'b' => 1 ), $response->get_data() ); + } + + /** + * Ensure that multiple comma-separated fields may be whitelisted with request['_fields']. + */ + public function test_rest_filter_response_fields_multi_field_filter() { + $response = new WP_REST_Response(); + $response->set_data( array( + 'a' => 0, + 'b' => 1, + 'c' => 2, + 'd' => 3, + 'e' => 4, + 'f' => 5, + ) ); + $request = array( + '_fields' => 'b,c,e' + ); + + $response = rest_filter_response_fields( $response, null, $request ); + $this->assertEquals( array( + 'b' => 1, + 'c' => 2, + 'e' => 4, + ), $response->get_data() ); + } + + /** + * Ensure that multiple comma-separated fields may be whitelisted + * with request['_fields'] using query parameter array syntax. + */ + public function test_rest_filter_response_fields_multi_field_filter_array() { + $response = new WP_REST_Response(); + + $response->set_data( array( + 'a' => 0, + 'b' => 1, + 'c' => 2, + 'd' => 3, + 'e' => 4, + 'f' => 5, + ) ); + $request = array( + '_fields' => array( 'b', 'c', 'e' ) + ); + + $response = rest_filter_response_fields( $response, null, $request ); + $this->assertEquals( array( + 'b' => 1, + 'c' => 2, + 'e' => 4, + ), $response->get_data() ); + } + + /** + * Ensure that request['_fields'] whitelists apply to items in response collections. + */ + public function test_rest_filter_response_fields_numeric_array() { + $response = new WP_REST_Response(); + $response->set_data( array( + array( + 'a' => 0, + 'b' => 1, + 'c' => 2, + ), + array( + 'a' => 3, + 'b' => 4, + 'c' => 5, + ), + array( + 'a' => 6, + 'b' => 7, + 'c' => 8, + ), + ) ); + $request = array( + '_fields' => 'b,c' + ); + + $response = rest_filter_response_fields( $response, null, $request ); + $this->assertEquals( array( + array( + 'b' => 1, + 'c' => 2, + ), + array( + 'b' => 4, + 'c' => 5, + ), + array( + 'b' => 7, + 'c' => 8, + ), + ), $response->get_data() ); + } + /** * The get_rest_url function should return a URL consistently terminated with a "/", * whether the blog is configured with pretty permalink support or not.