title: Acces raw data in Drupal 8 view template
body: <p>In a overridden template of the View module (views-view-field.html.twig), i'm trying to access to the raw data of a field.</p>
  
  <p>In the doc file, we can read this:</p>
  
  <pre><code> * Available variables:
  ...
   * - fields: A list of fields, each one contains:
  ...
   *   - raw: The raw data for the field, if it exists. This is NOT output safe.
  ...
  </code></pre>
  
  <p>but it's alway's empty.</p>
  
  <pre><code>{{ dump(fields.field_myfieldname) }}
  </code></pre>
  
  <p>print object(stdClass)[1899] ...</p>
  
  <pre><code>{{ dump(fields.field_myfieldname.raw) }}
  </code></pre>
  
  <p>print null</p>
  
  <p>I want the raw to build a file path from the value of a field.</p>
  
  <p>Why it's empty?
  Is there an other whay to get the raw data of a field in my template ? </p>
  
  <p>Edit : 
  I'm trying to do something like this: </p>
  
  <pre><code> &lt;img src="/path/to/image/{{ fields.title.raw | escape('uri')}}.jpg" /&gt; 
  </code></pre>
  
  <p>why is this so hard ? </p>