handle http accept headers more gracefully

lib/private/appframework/http/dispatcher.php

@@ -162,15 +162,8 @@ class Dispatcher {
 
 			// if none is given try the first Accept header
 			if($format === null) {
-				$header = $this->request->getHeader('Accept');
-				$formats = explode(',', $header);
-
-				if($header !== null && count($formats) > 0) {
-					$accept = strtolower(trim($formats[0]));
-					$format = str_replace('application/', '', $accept);
-				} else {
-					$format = 'json';
-				}
+                $headers = $this->request->getHeader('Accept');
+                $format = $controller->getResponderByHTTPHeader($headers);
             }
 
 			$response = $controller->buildResponse($response, $format);

lib/public/appframework/controller.php

@@ -70,6 +70,30 @@ abstract class Controller {
 	}
 
 
+    /**
+     * Parses an HTTP accept header and returns the supported responder type
+     * @param string $acceptHeader
+     * @return string the responder type
+     */
+    public function getResponderByHTTPHeader($acceptHeader) {
+        $headers = explode(',', $acceptHeader);
+
+        // return the first matching responder
+        foreach ($headers as $header) {
+            $header = trim($header);
+
+            $responder = str_replace('application/', '', $header);
+
+            if (array_key_exists($responder, $this->responders)) {
+                return $responder;
+            }
+        }
+
+        // no matching header defaults to json
+        return 'json';
+    }
+
+
 	/**
 	 * Registers a formatter for a type
 	 * @param string $format

tests/lib/appframework/controller/ControllerTest.php

@@ -30,6 +30,14 @@ use OCP\AppFramework\Http\JSONResponse;
 
 
 class ChildController extends Controller {
+
+	public function __construct($appName, $request) {
+		parent::__construct($appName, $request);
+		$this->registerResponder('tom', function ($respone) {
+			return 'hi';
+		});
+	}
+
 	public function custom($in) {
 		$this->registerResponder('json', function ($response) {
 			return new JSONResponse(array(strlen($response)));
@@ -161,5 +169,20 @@ class ControllerTest extends \PHPUnit_Framework_TestCase {
 	}
 
 
+	public function testDefaultResponderToJSON() {
+		$responder = $this->controller->getResponderByHTTPHeader('*/*');
+
+		$this->assertEquals('json', $responder);
+	}
+
+
+	public function testResponderAcceptHeaderParsed() {
+		$responder = $this->controller->getResponderByHTTPHeader(
+			'*/*, application/tom, application/json'
+		);
+
+		$this->assertEquals('tom', $responder);
+	}
+
 
 }