title: Strategy pattern in Symfony2
body: <p>I'm trying to build simple service for rendering various types of pages. Basic concept is having something like:</p>
  
  <pre><code>$somePageType = new PageType(...);
  $this-&gt;get('page.service')-&gt;render($somePagetype);
  </code></pre>
  
  <p>...which would be designed as <a href="http://en.wikipedia.org/wiki/Strategy_pattern" rel="noreferrer">Strategy pattern</a>. Page types would implement interface with <code>render</code> method and <code>page.service</code> would call it. The problem is I'd like to use Doctrine in page type classes. What are my options here? I'd like to avoid creating service for each of these classes. Is that even possible? Is it possible to make them container aware without being services? Possibly, in the future, some page type might need something more than only Doctrine, so I need to keep in mind also that.</p>