title: Laravel 4.2 Regular Expression Route Constraints, on fail
body: <p>I am trying to create a route in Laravel which uses regex validation, however I want to specify how the route should be handled if it fails. At the moment I have:</p>
  
  <pre><code>Route::group(array('prefix' =&gt; 'blog'), function() use($site) {
      Route::get('{filterType}/{filterTerm}', [ 'uses' =&gt; 'BlogController@index' ] )-&gt;where('filterType', 'author|topic');
  });
  </code></pre>
  
  <p>but I want something like this (totally made up):</p>
  
  <pre><code>Route::group(array('prefix' =&gt; 'blog'), function() use($site) {
      Route::get('{filterType}/{filterTerm}', [ 'uses' =&gt; 'BlogController@index' ] )-&gt;where('filterType', 'author|topic')-&gt;else(function(){
          // do something else
      });
  });
  </code></pre>
  
  <p>Essentially I want to handle validation of this blog route specific to the blog area, differently to the rest of the site.
  Perhaps there's something else to do this, any pointers would be great.</p>
  
  <p>Thanks</p>