title: Spring Webflow: cannot get flow execution url at action phase of portlet
body: <p>The following exception is thrown:    </p>
  
  <pre><code>Caused by: java.lang.IllegalStateException: A flow execution action URL can only be obtained in a RenderRequest using a 
  RenderResponse
      at org.springframework.webflow.context.portlet.PortletExternalContext.getFlowExecutionUrl(PortletExternalContext.java:2
  06)
      at org.springframework.webflow.engine.impl.RequestControlContextImpl.getFlowExecutionUrl(RequestControlContextImpl.java
  :178)
      at org.springframework.webflow.mvc.view.AbstractMvcView.render(AbstractMvcView.java:172)
      at org.springframework.webflow.engine.ViewState.render(ViewState.java:282)
      at org.springframework.webflow.engine.ViewState.refresh(ViewState.java:241)
      at org.springframework.webflow.engine.ViewState.resume(ViewState.java:219)
      at org.springframework.webflow.engine.Flow.resume(Flow.java:545)
      at org.springframework.webflow.engine.impl.FlowExecutionImpl.resume(FlowExecutionImpl.java:259)
      ... 62 more
  </code></pre>
  
  <p>It seems for me like resuming execution of flow at action phase tries to do render phase's stuff. Any ideas?</p>