title: Symfony route with several optional params
body: <p>first of all thanks for reading. I got a problem with Symfony routes. I got a single route that receives several parameters:</p>
  
  <pre><code>my_route:
      path:     /route/{page}/{paramA}/{paramB}/{paramC}
      defaults: { _controller: MyBundle:MyController:index, page: null, paramA: null, paramB: null, paramC: null }
  </code></pre>
  
  <p>The problem is with "paramA". Its a text to filter results, and it could  be unset, but "paramB" and "paramC" could be.</p>
  
  <p>So I need that route to handle for example:</p>
  
  <pre><code>/route/1/paramB/paramC
  </code></pre>
  
  <p>and receive in controller:</p>
  
  <pre><code>paramA = null, paramB="paramB", paramC="paramC"
  </code></pre>
  
  <p>Right now when I handle:</p>
  
  <pre><code>/route/1/paramB/paramC
  </code></pre>
  
  <p>I get this in the controller:</p>
  
  <pre><code>paramA="paramB", paramB="paramC", paramC=null
  </code></pre>
  
  <p>Any help would be welcome. Thanks again.</p>