eval 

<h:div class="summary">A flag on 'arg' to indicate that the value can be calculated.</h:div>
<h:div class="description">This is still experimental. if eval="_ijk_+3" and the value of the ijk was 2, this would change the value of the arg to 5. Only + and - are currently allowed</h:div>
<h:div class="summary">2006-05-21: PMR added attribute.</h:div>

Attribute Information

Used By

Attribute Group eval

Source 

<xsd:attribute name="eval" id="att.eval" type="xsd:string">
  <xsd:annotation>
    <xsd:documentation>
      <h:div class="summary">A flag on 'arg' to indicate that the value can be calculated.</h:div>
      <h:div class="description">This is still experimental. if eval="_ijk_+3" and the value of the ijk was 2, this would change the value of the arg to 5. Only + and - are currently allowed</h:div>
      <h:div class="summary">2006-05-21: PMR added attribute.</h:div>
    </xsd:documentation>
  </xsd:annotation>
</xsd:attribute>

Sample