title: eZPublish & Twig trans filter : chinese translation
body: <p>I'm currently working on the translation aspect of an eZPublish5 website which will contain 4 languages : french, english, russian and chinese, with french as original language and locale fallback.</p>
  
  <p>Translation of content in backend is working just fine but I'm struggling with translating template parts, which I have encapsulated in <code>{% trans %}</code> filters. I don't think it's directly related to a locale issue because <code>{% trans %}</code> tags are working with french, english and russian, but not in chinese.</p>
  
  <p>To do so I used
  <code>php ezpublish/console translation:update --output-format=xlf locale bundle --force</code> witch generated <em>messages.fr.xlf</em>, <em>messages.en.xlf</em>, and <em>messages.ru.xlf</em>.</p>
  
  <p>When in chinese, if I dump the locale in twig using <code>{{ app.request.locale }}</code> I get <strong>zh_TW</strong> for result, so I generated a <em>messages.zh_TW.xlf</em>, without any result.</p>
  
  <p>After a loooong web search regarding language codes of all sort, I started losing patience and generated :</p>
  
  <ul>
  <li><em>messages.chi.xlf</em></li>
  <li><em>messages.chi-TW.xlf</em></li>
  <li><em>messages.cn.xlf</em></li>
  <li><em>messages.zh.xlf</em></li>
  <li><em>messages.zh-tw.xlf</em></li>
  <li><em>messages.zh_TW.xlf</em></li>
  </ul>
  
  <p>to no avail.
  This project is my first with eZpublish and I my first multilanguage under the Twig/Symfony logic.</p>
  
  <p>Some code to show language declaration:</p>
  
  <pre><code>//ezpublish/config/ezpublish.yml
  ezpublish:
      system:
          chi:
              languages:
              - chi-TW
              - fre-FR
          session:
              name: eZSESSID
  </code></pre>
  
  <p>Any idea what am I doing wrong ?</p>