title: How to debug SpEL evaluation when it doesn't evaluate properly in WebFlow?
body: <p>I'm using Spring WebFlow 2.5.0, but my SpEL expression is not being evaluated correctly.  I figure I must be doing something wrong with either my WebFlow config or SpEL, however I'm not sure which.</p>
  
  <p>I've got the following decision state in my login-flow.xml:</p>
  
  <pre><code>&lt;decision-state id="submitChallenge"&gt;
      &lt;on-entry&gt;
          &lt;evaluate expression="authenticationService.respondToChallenge(externalContext.nativeRequest, authRequest)"  result="flowScope.challengeName" result-type="org.springframework.webflow.execution.Event"/&gt;
      &lt;/on-entry&gt;
      &lt;if test="flowScope.challengeName == 'success'" then="loginComplete" else="answerChallenge"/&gt;
  &lt;/decision-state&gt;
  </code></pre>
  
  <p>However, even if my <code>respondToChallenge()</code> method returns an Event.success(), I am never transitioned to the <code>loginComplete</code> state.  The test always seems to evaluate to FALSE.</p>
  
  <p>Is it my SpEL which is wrong, or the way I'm doing my evaluation/test?  How can I debug the SpEL evaluation to see what is happening?  </p>
  
  <p>I've tried to put debug points in the <code>org.springframework.binding.expression.spel.SpringELExpression</code> class but I'm kind of lost when I try to trace through the logic when executing a <code>getValue()</code>/etc.  All I can see is that it consistently evaluates to false.</p>