title: Primefaces dataTable edit cells next to header
body: <p>I'm trying to draw an assistance table with primefaces and I'm facing some troubles with <code>&lt;p:dataTable&gt;</code>.</p>
  
  <h1>The scenario</h1>
  
  <p>The table should be as follows:</p>
  
  <pre><code>-----------------------------------------------------------------------------------------
  |                         |                 Date and assistance (1)               |     |
  |          Name (1)       |-------------------------------------------------------|  %  |
  |                         |(4)|   |   |   |   |   |   |   |   |   |   |   |   |   |     |
  -----------------------------------------------------------------------------------------
  |Lastname, firstname (2)  |(3)|   |   |   |   |   |   |   |   |   |   |   |   |   | (5) |
  -----------------------------------------------------------------------------------------
  |...[more rows]...                                                                      |
  -----------------------------------------------------------------------------------------
  </code></pre>
  
  <p>In <code>(1)</code> I have the titles (not editable of course). In <code>(2)</code> I have the person data which is brought from the DB and is not editable also.</p>
  
  <p>In <code>(3)</code> I have an editable cell with a dropdown list for the possible values <code>[P, A, L]</code> (Present, Absent, Late).</p>
  
  <p>In <code>(4)</code> I need to insert the date of the assistance (not necessarily the current date).</p>
  
  <p>Finally, in <code>(5)</code> I have the current assistance percentage, which is a calculated field.</p>
  
  <h1>The problem</h1>
  
  <p>I'm not being able to to make <code>(4)</code> editable, e.g. with a <code>&lt;p:inputMask pattern="dd/MM"&gt;</code> tag</p>
  
  <h1>Failed Attempt</h1>
  
  <p>I tried with the grouping property of of <code>&lt;p:dataTable&gt;</code>, something like:</p>
  
  <pre><code>&lt;!-- Assist class has the properties char value, Person person and Date date --&gt;
  &lt;p:dataTable var="assist" value="#{assistBean.lstAssist}"
               editable="true" editMode="cell"&gt;
    &lt;p:columnGroup type="header"&gt;
      &lt;!-- The "headers" properly said --&gt;
      &lt;p:row&gt;
        &lt;p:column rowspan="2" headerText="Name"/&gt;
        &lt;p:column colspan="#{someBean.colAmount}" rowspan="1" headerText="Date and assistance"/&gt;
      &lt;/p:row&gt;
  
      &lt;!-- The editable dates --&gt;
      &lt;p:row&gt;
        &lt;p:column&gt;
          &lt;p:cellEditor&gt;
            &lt;f:facet name="output"&gt;
              &lt;h:outputText value="#{assist.date}"&gt;
                &lt;f:convertDateTime pattern="dd/MM"/&gt;
              &lt;/h:outputText&gt;
            &lt;/f:facet&gt;
            &lt;f:facet name="input"&gt;
              &lt;p:inputMask value="#{assist.date}" style="width:96%" mask="99/99"/&gt;
            &lt;/f:facet&gt;
          &lt;/p:cellEditor&gt;
        &lt;/p:column&gt;
      &lt;/p:row&gt;
    &lt;/p:columnGroup&gt;
  
    &lt;p:column&gt;...
      ... The rest of the table
    &lt;/p:column&gt;
  &lt;/p:dataTable&gt;
  </code></pre>
  
  <p>This doesn't work because every field in the <code>&lt;p:columnGroup type="header"&gt;</code> doesn't renders the <code>&lt;input&gt;</code>.</p>
  
  <p>I also tried some other combinations but I can't mix the headers with the editable cells.</p>
  
  <p>Any help or guide will be appreciated, I'm also open to other options. Thanks in advance</p>