title: Why are jqGrid fields hidden in form edit, even though "edithidden:true" is included in the colModel?
body: <p>Using jqGrid 4.3.1, I have some columns which are hidden in grid view, but I would like them to be visible and editable in an edit form.</p>
  
  <p>According to the <a href="http://www.trirand.com/jqgridwiki/doku.php?id=wiki:common_rules" rel="nofollow noreferrer">documentation</a>, the <code>edithidden</code> sub-option of the <code>editrules</code> option of the <code>colModel</code> module enables the exact behaviour I desire (emphasis mine):</p>
  
  <blockquote>
    <p>This option is valid only in form editing module. By default the hidden fields are not editable. <strong>If the field is hidden in the grid and edithidden is set to true, the field can be edited when add or edit methods are called.</strong></p>
  </blockquote>
  
  <p>However, when I implement the following code:</p>
  
  <pre><code>{name:'AcmeCoValue',editrules: {edithidden: true}, editable: true, show:'AcmeCovalue', hidden:true, fixed:'true', width: 65},
  </code></pre>
  
  <p>the rendered HTML of the edit form shows this field as:</p>
  
  <pre><code>&lt;tr style="display:none" rowpos="7" class="FormData" id="tr_RedCoValue"&gt;
  </code></pre>
  
  <p>which is the same behaviour I have when I set:</p>
  
  <pre><code>editrules: {edithidden: false}
  </code></pre>
  
  <p>which seems to me like the <code>edithidden</code> parameter is ineffective.</p>
  
  <p>The only way I've found to make it visible is to force the field onto a visible row with the <code>formoptions:{rowpos:7}</code> option, which makes the field visible even when <code>edithidden: false</code>.</p>
  
  <p>Why doesn't edithidden seem to have any effect?</p>
  
  <p>This is legacy code which I inherited. Is there anything I should check, which might be overriding the expected behaviour of <code>edithidden</code>?</p>
  
  <p>I think I can manually implement the behaviour I desire in Javascript but I would prefer to do it the "jqGrid" way for simplicity and maintainability, and I also worry about why it doesn't work, and what other problems might be related to this one.</p>