Laravel 4.1 Route Filters

-- filters.php excerpt --

Route::filter('cache', function ($route, $request, $response = null, $cacheLifetime = null) {
    $key = sha1($request->url());

    if (is_null($response) and Cache::has($key)) {
        return Cache::get($key);
    }

    if (!is_null($response) and !Cache::has($key)) {

        if (is_null($cacheLifetime)) {
            $cacheLifetime = 30;
        }

        Cache::put($key, $response->getContent(), $cacheLifetime);
    }
});

Route::filter('markdown', function ($route, $request, $response = null) {

    Clockwork::startEvent('markdown.parse', 'Parsing Markdown');
    $transformedResponse = MarkdownExtra::defaultTransform($response->getContent());
    Clockwork::endEvent('markdown.parse');

    $response->setContent($transformedResponse);
});

-- routes.php excerpt --

Route::get('/markdown-test', function () {

    return file_get_contents(app_path() . '/test.md');

})->before('cache')->after('markdown|cache:30');

-- Result --

# Initial Request
1. Request made
2. Transformed via Markdown
3. Stored in Cache
4. Displayed transformed response

# Subsequent Requests
1. Request made
2. Returned data retrieved from Cache
3. Overwritten with content from Route::get closure
4. Transformed via Markdown
5. Displayed transformed response
6. Done

-- Expected --

# Initial Request
1. Request made
2. Transformed via Markdown
3. Stored in Cache
4. Displayed transformed response

# Subsequent Requests
1. Request made
2. Displayed data retrieved from Cache
3. Done