How to solve refreshing issues in Facelets and Spring Web Flow?

Question

For my particular project, I'm using Facelets (1.1.14), MyFaces (1.2.3), and Spring Web Flow (2.0.3). My IDE is JDeveloper 10.1.3.3. My browser is IE6 (work requirement).

Okay...ran into a very weird issue today. Normally, when I'm using Facelets, I can make whatever changes I want to my xhtml file, refresh my browser window, and see the changes immediately. I've got Facelets development set to true, and Facelets refresh period set to 1.

Up to this afternoon, I've had no problem with Facelets refreshes on this project. However, just this afternoon, I starting finding that changes to css styles and classes did not appear when I refreshed the page. Then I started seeing similar issues with other page elements. In some cases the changes never appear. At other times, I can refresh the page after a little while has passed and the changes have been reflected.

What happened to my Facelets page refreshes? It's like they've gone all sticky. I'm used to immediate changes on page refresh without complications. Has anyone run into this before? Any solutions or suggestions?

EDIT

The issue has something to do with Spring Web Flow. One of my pages is pure Facelets, and it's reflecting changes on refresh immediately. My other xhtml pages are invoked as view states in my flow definitions, and show the symptoms described above. Still, they were working fine just a day or two ago...

EDIT

Ok, I've been able to isolate the symptom, but I still don't know its cause.

It seems that whenever I have a facelets xhtml file that is rendered as a view-state of a flow and has an h:form element, then I get odd behavior when I make changes to the JSF elements on my page and refresh my browser. This includes not showing changes in their styles or style classes.

Changes to regular HTML elements (like changing the style of an input element) seem to work fine. Changing the h:form to a regular HTML form allow for immediate changes on page refresh, even on JSF elements. When I view the page when I'm not executing a flow (just using Facelets), then I never encounter any problems, even when using an h:form.

Please tell me someone has encountered this before, and has some solution. Anyone?

Answer 1

I'm not sure if this applies to Web Flow, but I do know that with Spring MVC, you have an option of having your controller implement the LastModified interface, which allows Spring to send the browser the "Last-Modified" HTTP header.

Servlets typically don't set this HTTP header value, causing browsers to request a new copy of the files each time, however, if the "Last-Modified" header is set, browsers know not to retrieve the contents of a URL if it hasn't been modified since the page was last retrieved.

I suspect your Web Flow "controller" (pardon my abuse of terminology, I'm not familiar with Web Flow) is setting the "Last-Modified" header, while your regular Facelets page is not.

For what it's worth, I think setting Last-Modified is generally a good idea, unless your page is dynamic.