title: Problem with dynamic action state
body: <p>I Have problem with Spring Webflow. My flow XML definition is:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;flow xmlns="http://www.springframework.org/schema/webflow"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.springframework.org/schema/webflow
          http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd" parent="changeLang"&gt;
  
      &lt;input name="hash" required="true"/&gt;
  
      &lt;action-state id="decideAction"&gt;
          &lt;set name="flowScope.goTo" value ="verifyActionService.verifyHash(hash)" /&gt;
          &lt;transition to="${goTo}" &gt;&lt;/transition&gt; 
      &lt;/action-state&gt;
  
      &lt;view-state id="correctVerify" view="registered" model="userAddressesForm"&gt;
          &lt;transition on="addPhoneNumber" to="correctVerify"&gt;
              &lt;evaluate expression="verifyActionService.addPhoneNumber(userAddressesForm)" /&gt;
          &lt;/transition&gt;
          &lt;transition on="deletePhoneNumber" to="correctVerify"&gt;
              &lt;evaluate expression="verifyActionService.deletePhoneNumber(userAddressesForm, requestParameters.deleteNumber)" /&gt;
          &lt;/transition&gt;
      &lt;/view-state&gt;
  
      &lt;view-state id="notCorrectVerify" view="register"&gt;&lt;/view-state&gt;
  
  &lt;/flow&gt;
  </code></pre>
  
  <p>The method verifyHash return a state id equal "correctVerify" like this:</p>
  
  <pre><code>public String verifyHash(String hash) {
      return "correctVerify";
  }
  </code></pre>
  
  <p>When I run it, a get an error like this:</p>
  
  <pre><code>at java.lang.Thread.run(Thread.java:662)
  Caused by: java.lang.IllegalArgumentException: Cannot find state with id '${goTo}' in flow 'verify' -- Known state ids are 'array&lt;String&gt;['decideAction', 'correctVerify', 'notCorrectVerify', 'start']'
  at org.springframework.webflow.engine.Flow.getStateInstance(Flow.java:348)
  at org.springframework.webflow.engine.support.DefaultTargetStateResolver.resolveTargetState(DefaultTargetStateResolver.java:60)
  at org.springframework.webflow.engine.Transition.execute(Transition.java:217)
  at org.springframework.webflow.engine.impl.FlowExecutionImpl.execute(FlowExecutionImpl.java:391)
  at org.springframework.webflow.engine.impl.RequestControlContextImpl.execute(RequestControlContextImpl.java:214)
  at org.springframework.webflow.engine.TransitionableState.handleEvent(TransitionableState.java:119)
  </code></pre>
  
  <p>Can anybody help me?</p>