404 HTTP errors not being rendered in JSON using Zend framework 2 - zend-framework2

Question

I'm creating a simple restful api using zend framework2 and I've references Rob Allen's notes on the subject as well as this excellent tutorial by http://hounddog.github.com/blog/getting-started-with-rest-and-zend-framework-2/
below is my module_config.php. You'll see that I have routes and the JSON view strategy configured. My understanding is that when you set up the JSON strategy in this fashion it accommodates all modules. The issue is that when an invalid route is entered the 404 response is sent back in html even though the Accept header is requesting Application/json.
I've been struggling with this for a 2 days now any advice or help would be appreciated
This curl call to the api generates the expected 404 error.
curl -i -H "Accept: application/json" http://myapi-dev.local/xxx/1
Module_config.php
return array(
'controllers' => array(
'invokables' => array(
'Dips\Controller\Roles' => 'Dips\Controller\RolesController', //maps controller alias to a physical controller
),
),
'router' => array(
'routes' => array(
'dips' => array(
'type' => 'segment',
'options' => array(
'route' => '/dips/roles/:apikey/:uname/:appname',
'constraints' => array(
'apikey' => '[a-zA-Z0-9]+',
'uname' => '[a-zA-Z]+',
'appname' => '[a-zA-Z][a-zA-Z0-9_-]*',
),
'defaults' => array(
'controller' => 'Dips/Controller/Roles',
),
),
),
),
),
'view_manager' => array(
'strategies' => array(
'ViewJsonStrategy',
),
),
);

Answer 1

You would need to implement an additional rendering strategy and put it in the stack above the default 404 rendering strategy. Alternatively, you could extend the existing ViewJsonStrategy to include error handling.
The default 404 Strategy is Zend/Mvc/View/Http/RouteNotFoundStrategy. If you look at it's detectNotFoundError method, you can see when it gets triggered.