Currently Webflow is very transition oriented, which is understandable given a definition of a "flow". However, some flow states require a higher level of interaction without needing to transition: e.g. AJAX request/response on user input / time outs / events / etc..
AJAX requests are easy => fire up a JQuery.ajax.. and the request is sent.
Responses are quite hard with the current state of the Webflow.
In general, since a Webflow is not well interaction oriented, a simple @Controller can accept such JQuery AJAX request, and serve up those JSON responses [ going out of the Webflow state machine ].
BUT.. in most cases a flowScope would contain lots of useful data, possibly even from previous steps, which the server would need in order to create that intelligent response.
Currently there is no Webflow'ish / Spring MVC'ish way to access that "flowScoped" data in a @Conroller
Alternative solutions maybe used: keep/duplicate all this data in cache that can be accessed by the server and the client; send all 150 fields back to the server in that JQuery AJAX request, etc.. => not clean at all.
WHAT PEOPLE WANT:
Would be very useful and clean to have something like [notice the "@Flow"]:
here is the supporting resource: http://ytoh.wordpress.com/2011/09/07/flow-accessing-webflow-data-in-spring-mvc-controllers/
Other annotations / ideas are also welcome. Let's make AJAX responses simple in Spring Webflow => there is no reason for it not to be simple.