title: Accessing a variable set in a child template from the parent template with Twig
body: <p>I have the following setup in my templates. I have numerous child templates like this where the <code>subject</code> block is different every time.</p>
  
  <p>Is there a way for me to access the <code>subjectTitle</code> variable set in the child from the parent?</p>
  
  <p>Parent:</p>
  
  <pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"&gt;
      &lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;
      &lt;head&gt;
          &lt;meta http-equiv="Content-Type" content="text/html; charset=utf-8"/&gt;
          &lt;meta name="viewport" content="width=device-width"/&gt;
      &lt;/head&gt;
      &lt;body&gt;
      &lt;span style="display: none !important;"&gt;{{ preHeader }}&lt;/span&gt;
  </code></pre>
  
  <p>Child:</p>
  
  <pre><code>{% extends 'CRMPiccoMailerBundle:Email:base.html.twig' %}
  {% block subject %}
      {% set subjectTitle = 'Thanks for ordering! Your Order is 1872.' %}
      {{ subjectTitle }}
  {% endblock %}
  </code></pre>