Merge pull request #125 from tarjei/readme

Add more info about the exception handler to the Readme

README.md

@@ -402,7 +402,7 @@ ExceptionController support
 Using this custom ExceptionController it is possible to leverage the View layer
 when building responses for uncaught Exceptions.
 
-The RestBundle view-layer-aware ExceptionController is enabled as follows:
+To enable the RestBundle view-layer-aware ExceptionController update the framework section of your config like this:
 
 ```yaml
 # app/config/config.yml
@@ -425,6 +425,25 @@ fos_rest:
             'Acme\HelloBundle\Exception\MyExceptionWithASafeMessage': true
 ```
 
+If you want to display the message from the exception in the content of the response, add the 
+exception to the messages map as well. If not only the statuscode will be returned. 
+
+If you know what status code you want to return you do not have to add a mapping, you can do
+this in your controller:
+
+```php
+<?php
+class UsersController extends Controller
+{
+    public function postUserCommentsAction($slug)
+    {
+        if (!$this->validate($slug)) {
+            throw new HttpException(400, "New comment is not valid.");
+        }
+    }
+}
+```
+
 See the following example configuration for more details:
 https://github.com/lsmith77/symfony-standard/blob/techtalk/app/config/config.yml