title: JSF EL expression does not work in required attribute of HtmlInputText
body: <p>I am adding JSF components dynamically into an XHTML page created using JSF 1.2 with facelets. The required validation of some of these components have to be carried out only when a specfic button in the page is clicked.
  So I've added the required attribute as an EL expression using the code:</p>
  
  <pre><code>String requiredExpression = "#{not empty param['form:button']}")
  component.setValueExpression("required", 
                         createValueExpression(requiredExpression, String.class));
  </code></pre>
  
  <p>I have verified that the EL expression works by placing it in the required attribute of one of the static components in the page. I have also verified that the EL expression is getting added to the component by debugging the code. But it just does not work in the dynamic components.</p>