JSF/Mojarra “flash scope” problems

Question

I've got an app running on Mojarra 2.1.1 / Glassfish 3.1 which has now grown to 150,000+ lines of code. The app uses ajax extensively with ViewScoped managed beans and the page-redirect-get pattern (i.e. faces-redirect=true).

One thing that is continually annoying me is the apparent lack of ease of passing parameters from page to page, and bean to bean (every page has it's own backing bean).

I've not been able to get the flash working. I typically need to access the data I've written to the flash in the preRenderView event listener of the next page. This doesn't work reliably, particularly after an application redeployment.

I've read up on CDI and have spent a few days trying to migrate from JSF managed beans to CDI beans, but can't get it to work. There seems to be a lot of compatibility issues between Seam 3 and Glassfish 3.1. I upgraded Weld to 1.1.1 but this doesn't help. From my perspective it just doesn't work at the moment. When I say doesn't work, for example I have a page trying to h:inputText into a String in the backing bean and this doesn't work, really simple stuff.

Because of the CDI problems I'm having I can't use seam-faces @RenderScoped which in a very simple test application (even on g/f 3.1) does just what I want, but not in the complex main application.

The only reliable mechanism I can find to use at present is URL parameters which are a security nightmare. Even though every effort is made to ensure that access to data is properly authenticated there's always the change of missing something, and seeing ...xhtml?id=51031 or whatever in the browser is too much for some people to resist trying other ids. I've written an obfuscation converter to avoid clear text and don't use meaningful names for the name/value pairs, but this doesn't get to the root of the problem.

I just wondered if I was missing something here, has everyone else got a working solution to this problem, even on glassfish? Am I worrying too much and should stick with URL params? Any other suggestions?

Thanks.

Answer 1

I saw the same. At the time I tried it Seam3 was very buggy and it's very hard to get it deployed to different servers. I switched to MyFaces CODI which worked without any problems from the very beginning. In your case you should have a look at @ViewAccessScoped. You can get rid of all those annoying workarounds.

Answer 2

Declare the parameters which you'd like to set or pass through to the next view in a

<f:metadata>
    <f:viewParam name="foo" value="#{bean.foo}" />
</f:metadata>

This does basically bean.setFoo(request.getParameter("foo")) during update model values phase of the GET request.

If you add includeViewParams=true parameter to the navigation outcome, then the ones which are declared as <f:viewParam> of the current view will be passed through to the next view.

public String doSomething() {
    // ...
    return "next?faces-redirect=true&includeViewParams=true";
}

(note: the & is important! the & won't work as it's not XML-valid)

The next view should have the same <f:viewParam> to get them to set in the bean. And so on.