<p dir="auto">If this is something that can't be added or isn't going to be supported, it wouldn't be a bad thing to support hierarchical data in forms (adjacency list model / nested set model).</p>
<p dir="auto">Possibly having the option to force the selection of leafs without children only, etc, etc.  Can lead to a very powerful feature. =)</p>
<table role="table">
<thead>
<tr>
<th>Q</th>
<th>A</th>
</tr>
</thead>
<tbody>
<tr>
<td>Bug report?</td>
<td>yes</td>
</tr>
<tr>
<td>Feature request?</td>
<td>no</td>
</tr>
<tr>
<td>BC Break report?</td>
<td>no</td>
</tr>
<tr>
<td>RFC?</td>
<td>no</td>
</tr>
<tr>
<td>Symfony version</td>
<td>3.4.0-BETA1</td>
</tr>
</tbody>
</table>
<p dir="auto">Since upgrading to Symfony 3.4.0-BETA1 fom 3.3.10, suddenly all responses started receiving <code class="notranslate">Cache-Control</code> header with <code class="notranslate">private, max-age=10800, no-cache, private</code> value and a response code <code class="notranslate">304 Not Modified</code>, which means that responses are cached in browsers for 3 hours and only hard reload with <code class="notranslate">Ctrl+R</code> or <code class="notranslate">Shift+R</code> refreshes the page from backend.</p>
<p dir="auto"><code class="notranslate">git bisect</code> says that the culprit is <a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="264689355" data-permission-text="Title is private" data-url="https://github.com/symfony/symfony/issues/24523" data-hovercard-type="pull_request" data-hovercard-url="/symfony/symfony/pull/24523/hovercard" href="https://github.com/symfony/symfony/pull/24523">#24523</a>. And indeed, reverting the commit in that PR fixes the issue for me, meaning <code class="notranslate">Cache-Control</code> header is back to <code class="notranslate">no-cache, private</code> and the response is <code class="notranslate">200 OK</code>.</p>