An external form in Activiti means that you implement all the view and navigation logic yourself. The form key in Activiti is just an identifier that you can use to render the right view. So what's your question exactly?
hi thank u for your answer … i need to have dynamic form that should be use External from . i work with Vaadin how to use external form activiti in vaadin have a sample? i search in net, don't found it! i think , xform is best option … http://saeidmirzaeitech.wordpress.com/2012/10/31/using-activiti-with-xform/ can u any help?
I tried to explain that this is not part of the Activiti project, it's part of writing a Vaadin web application. So if you need help with Vaadin, their forums are a better place to get started.