Put the JSF UI component lifecycle under the control of a Spring Web Flow Execution [SWF-362]

[spring-operator]

Keith Donald opened SWF-362 and commented

Currently Spring Web Flow "fits" into the JSF lifecycle via a FlowPhaseListener. This is a simple integration approach, however it has several disadavantages:

• All of the code related to flow execution lifecycle management is JSF specific, and duplicated with the FlowExecutor which processes requests in the other supported environments. Special constructs like a FlowCleanupFilter must be maintained because of limitations in the JSF lifecycle.
• Exceptions that occur outside the Flow Execution cannot be handled by the FlowExecution. For example, consider an exception that occurs when a UIComponent renders. Such an exception is impossible to handle by the Flow. Special-case JSF extensions must be written to deal with these exceptions.
• Issuing cleanup callbacks like session.disconnect() after view rendering is hard to do, and adapter (e.g. JSF) specfiic
• Supporting JSF in a Portlet environment is harder, and results in further portlet-specific integration code
• In general, SWF has less control over things, making it harder to fully utilize its power.

This issue should investigate putting Web Flow itself in full control of driving the JSF component lifecycle. This will allow for high-level JSF + SWF integration code to be eliminated, and for common request dispatching and flow execution lifecycle management code to be reused consistently across all integration environments.

This enhancement most likely depends on enhancements to the core engine to complete. Specifically, a view selection rendering phase most likely will needed to be added to the SWF lifecycle. Also, this enhancement would benefit from several core engine enhancements. Specifically, the ability to fork off flow executions asynchronously from within a view state (called flow composition).

---

Affects: 1.0.4

Issue Links:

• Put the View Rendering Lifecycle under control of Spring Web Flow with complete support for Spring MVC and JSF views [SWF-367] #1218 Put the View Rendering Lifecycle under control of Spring Web Flow with complete support for Spring MVC and JSF views
  ("depends on")
• FlowExecutionHolder not available during portlet render phase [SWF-318] #1194 FlowExecutionHolder not available during portlet render phase
  ("is depended on by")
• Have generated flow execution URLs match the current view [SWF-288] #1179 Have generated flow execution URLs match the current view
  ("is depended on by")
• Introduce support for handling flow execution restoration failures due to flow expiry or browser backtracking [SWF-289] #1180 Introduce support for handling flow execution restoration failures due to flow expiry or browser backtracking
  ("is depended on by")
• Make it possible for Web Flow to handle errors thrown from within JSF views [SWF-345] #1206 Make it possible for Web Flow to handle errors thrown from within JSF views
  ("is depended on by")
• Preserve the UIViewRoot across a redirect. [SWF-348] #1209 Preserve the UIViewRoot across a redirect.
  ("is depended on by")
• Complete Portlet integration for Web Flow 2.x, including JSF + SWF integration in a Portlet environment. [SWF-183] #1100 Complete Portlet integration for Web Flow 2.x, including JSF + SWF integration in a Portlet environment.

[spring-operator]

Keith Donald commented

The JSF lifecycle is now fully under the control of Web Flow, and this integration approach is so much cleaner.