REST API: Support a broader range of JSON media types.

Previously, we only supported `application/json` which prevented using subtypes like `application/activity+json`. This allows for the REST API to `json_decode` the body of requests using a JSON subtype `Content-Type`. Additionally, `wp_die()` now properly sends the error as JSON when a JSON subtype is specified in the `Accept` header.

Props pfefferle.
Fixes #49404.


git-svn-id: https://develop.svn.wordpress.org/trunk@49329 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/load.php

@@ -1595,11 +1595,11 @@ function wp_finalize_scraping_edited_file_errors( $scrape_key ) {
  */
 function wp_is_json_request() {
 
-	if ( isset( $_SERVER['HTTP_ACCEPT'] ) && false !== strpos( $_SERVER['HTTP_ACCEPT'], 'application/json' ) ) {
+	if ( isset( $_SERVER['HTTP_ACCEPT'] ) && wp_is_json_media_type( $_SERVER['HTTP_ACCEPT'] ) ) {
 		return true;
 	}
 
-	if ( isset( $_SERVER['CONTENT_TYPE'] ) && 'application/json' === $_SERVER['CONTENT_TYPE'] ) {
+	if ( isset( $_SERVER['CONTENT_TYPE'] ) && wp_is_json_media_type( $_SERVER['CONTENT_TYPE'] ) ) {
 		return true;
 	}
 
@@ -1635,6 +1635,24 @@ function wp_is_jsonp_request() {
 
 }
 
+/**
+ * Checks whether a string is a valid JSON Media Type.
+ *
+ * @since 5.6.0
+ *
+ * @param string $media_type A Media Type string to check.
+ * @return bool True if string is a valid JSON Media Type.
+ */
+function wp_is_json_media_type( $media_type ) {
+	static $cache = array();
+
+	if ( ! isset( $cache[ $media_type ] ) ) {
+		$cache[ $media_type ] = (bool) preg_match( '/(^|\s|,)application\/([\w!#\$&-\^\.\+]+\+)?json(\+oembed)?($|\s|;|,)/i', $media_type );
+	}
+
+	return $cache[ $media_type ];
+}
+
 /**
  * Checks whether current request is an XML request, or is expecting an XML response.
  *

src/wp-includes/rest-api/class-wp-rest-request.php

@@ -323,6 +323,19 @@ class WP_REST_Request implements ArrayAccess {
 		return $data;
 	}
 
+	/**
+	 * Checks if the request has specified a JSON content-type.
+	 *
+	 * @since 5.6.0
+	 *
+	 * @return bool True if the content-type header is JSON.
+	 */
+	public function is_json_content_type() {
+		$content_type = $this->get_content_type();
+
+		return isset( $content_type['value'] ) && wp_is_json_media_type( $content_type['value'] );
+	}
+
 	/**
 	 * Retrieves the parameter priority order.
 	 *
@@ -335,8 +348,7 @@ class WP_REST_Request implements ArrayAccess {
 	protected function get_parameter_order() {
 		$order = array();
 
-		$content_type = $this->get_content_type();
+		if ( $this->is_json_content_type() ) {
-		if ( isset( $content_type['value'] ) && 'application/json' === $content_type['value'] ) {
 			$order[] = 'JSON';
 		}
 
@@ -658,9 +670,7 @@ class WP_REST_Request implements ArrayAccess {
 		$this->parsed_json = true;
 
 		// Check that we actually got JSON.
-		$content_type = $this->get_content_type();
+		if ( ! $this->is_json_content_type() ) {
-
-		if ( empty( $content_type ) || 'application/json' !== $content_type['value'] ) {
 			return true;
 		}
 

tests/phpunit/tests/functions.php

@@ -1728,4 +1728,27 @@ class Tests_Functions extends WP_UnitTestCase {
 			array( '03:61:59', false ), // Out of bound.
 		);
 	}
+
+	/**
+	 * @ticket 49404
+	 * @dataProvider data_test_wp_is_json_media_type
+	 */
+	public function test_wp_is_json_media_type( $input, $expected ) {
+		$this->assertEquals( $expected, wp_is_json_media_type( $input ) );
+	}
+
+
+	public function data_test_wp_is_json_media_type() {
+		return array(
+			array( 'application/ld+json', true ),
+			array( 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"', true ),
+			array( 'application/activity+json', true ),
+			array( 'application/json+oembed', true ),
+			array( 'application/json', true ),
+			array( 'application/nojson', false ),
+			array( 'application/no.json', false ),
+			array( 'text/html, application/xhtml+xml, application/xml;q=0.9, image/webp, */*;q=0.8', false ),
+			array( 'application/activity+json, application/nojson', true ),
+		);
+	}
 }

tests/phpunit/tests/rest-api/rest-request.php

@@ -178,6 +178,87 @@ class Tests_REST_Request extends WP_UnitTestCase {
 		$this->assertEmpty( $this->request->get_param( 'has_json_params' ) );
 	}
 
+	public static function alternate_json_content_type_provider() {
+		return array(
+			array( 'application/ld+json', 'json', true ),
+			array( 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"', 'json', true ),
+			array( 'application/activity+json', 'json', true ),
+			array( 'application/json+oembed', 'json', true ),
+			array( 'application/nojson', 'body', false ),
+			array( 'application/no.json', 'body', false ),
+		);
+	}
+
+	/**
+	 * @ticket 49404
+	 * @dataProvider alternate_json_content_type_provider
+	 *
+	 * @param string  $content_type The content-type
+	 * @param string  $source The source value.
+	 * @param boolean $accept_json The accept_json value.
+	 */
+	public function test_alternate_json_content_type( $content_type, $source, $accept_json ) {
+		$this->request_with_parameters();
+
+		$this->request->set_method( 'POST' );
+		$this->request->set_header( 'Content-Type', $content_type );
+		$this->request->set_attributes( array( 'accept_json' => true ) );
+
+		// Check that JSON takes precedence.
+		$this->assertEquals( $source, $this->request->get_param( 'source' ) );
+		$this->assertEquals( $accept_json, $this->request->get_param( 'has_json_params' ) );
+	}
+
+	public static function is_json_content_type_provider() {
+		return array(
+			array( 'application/ld+json', true ),
+			array( 'application/ld+json; profile="https://www.w3.org/ns/activitystreams"', true ),
+			array( 'application/activity+json', true ),
+			array( 'application/json+oembed', true ),
+			array( 'application/nojson', false ),
+			array( 'application/no.json', false ),
+		);
+	}
+
+	/**
+	 * @ticket 49404
+	 * @dataProvider is_json_content_type_provider
+	 *
+	 * @param string  $content_type The content-type
+	 * @param boolean $is_json The is_json value.
+	 */
+	public function test_is_json_content_type( $content_type, $is_json ) {
+		$this->request_with_parameters();
+
+		$this->request->set_header( 'Content-Type', $content_type );
+
+		// Check for JSON content-type.
+		$this->assertEquals( $is_json, $this->request->is_json_content_type() );
+	}
+
+	/**
+	 * @ticket 49404
+	 */
+	public function test_content_type_cache() {
+		$this->request_with_parameters();
+		$this->assertFalse( $this->request->is_json_content_type() );
+
+		$this->request->set_header( 'Content-Type', 'application/json' );
+		$this->assertTrue( $this->request->is_json_content_type() );
+
+		$this->request->set_header( 'Content-Type', 'application/activity+json' );
+		$this->assertTrue( $this->request->is_json_content_type() );
+
+		$this->request->set_header( 'Content-Type', 'application/nojson' );
+		$this->assertFalse( $this->request->is_json_content_type() );
+
+		$this->request->set_header( 'Content-Type', 'application/json' );
+		$this->assertTrue( $this->request->is_json_content_type() );
+
+		$this->request->remove_header( 'Content-Type' );
+		$this->assertFalse( $this->request->is_json_content_type() );
+	}
+
 	public function test_parameter_order_json() {
 		$this->request_with_parameters();