By default when a flow enters a view state, it executes a client-side redirect before rendering the view. This approach is known as POST-REDIRECT-GET. It has the advantage of separating the form processing for one view from the rendering of the next view. As a result the browser Back and Refresh buttons work seamlessly without causing any browser warnings.

Normally the client-side redirect is transparent from a user's perspective. However, there are situations where POST-REDIRECT-GET may not bring the same benefits. For example sometimes it may be useful to embed a flow on a page and drive it via Ajax requests refreshing only the area of the page where the flow is rendered. Not only is it unnecessary to use client-side redirects in this case, it is also not the desired behavior with regards to keeping the surrounding content of the page intact.

To indicate a flow should execute in "page embedded" mode all you need to do is pass an extra flow input attribute called "mode" with a value of "embedded". Below is an example of a top-level container flow invoking a sub-flow in an embedded mode:

<subflow-state id="bookHotel" subflow="booking">
    <input name="mode" value="'embedded'"/>
</subflow-state>
    

When launched in "page embedded" mode the sub-flow will not issue flow execution redirects during Ajax requests.

If you'd like to see examples of an embedded flow please refer to the webflow-primefaces-showcase project. You can check out the source code locally, build it as you would a Maven project, and import it into Eclipse:

cd some-directory
svn co https://src.springframework.org/svn/spring-samples/webflow-primefaces-showcase
cd webflow-primefaces-showcase
mvn package
# import into Eclipse

The specific example you need to look at is under the "Advanced Ajax" tab and is called "Top Flow with Embedded Sub-Flow".