title: Evaluating expression inside GSP tags
body: <p>I am trying to evaluate an expression in a GSP tag. Crudely put,</p>
  
  <pre><code>&lt;g:form ${true ? 'name=\"hello\"' : ''}&gt;
  </code></pre>
  
  <p>But the error I'm getting is:</p>
  
  <pre><code>Class: org.codehaus.groovy.grails.web.taglib.exceptions.GrailsTagException
  Message: Attribute value must be quoted (${true ? 'name=\"hello\"' : ''}).
  </code></pre>
  
  <p>In one of the other views, the following expression (which is similar to the above one) works fine.</p>
  
  <pre><code>&lt;li ${controllerName == null ? ' class=active' : ''}&gt;
  </code></pre>
  
  <p>But it does not work with the form tag. I am using Grails 2.3.5. Any idea what I'm doing wrong?</p>
  
  <p>Edit: I am having similar problems with this expression too.</p>
  
  <pre><code>&lt;g:form url="[${multiple ? '' : 'resource:xyzInstance, '}action:'update']" method="PUT" &gt;
  </code></pre>
  
  <p>Here, <code>multiple</code> is a boolean value. It works fine with an <code>&lt;g:if&gt;</code> tag.</p>
  
  <pre><code>&lt;g:if test="${multiple}"&gt;
  </code></pre>