Bug in the spec ;)
regards,
Martin
On Fri, Feb 22, 2008 at 6:35 PM, Matthias Wessendorf <[EMAIL PROTECTED]> wrote:
> Hi,
>
> it can be the case, that this mail may be a bit long..., but the main
> question I think is:
> Is there a public getPhaseListeners() method missing on UIVIewRoot ?
>
> Some general information since JSF 1.2... there is a public
> addPhaseListener() on UIViewRoot.
> So you can register a PhaseListener with the current view root (per
> view) to have beforePhase and afterPhase called
> on these lifecycle phases:
> -ApplyReqValue
> -processValidation
> -UpdateModel
> -Invoke App
> -RenderResponse
>
> You can add such a PL (PhaseListener) via the mentioned Java API or:
> <f:phaseListener type="blah.MyPL" />
> (this internally uses the Java API ....)
>
> Fine.
>
> now when you render a page and do a (regular) postback the
> phaselistener (its methods...) is executed.
> Fine.
>
> Now the "ajax" scenario.
>
> Some libraries (like ADF Faces Rich Client or Apache MyFaces
> Tobago(not Trinidad ;-) )) offer a custom lifecycle to call the
> lifecycle methods (such as processXyz()) only
> on the components, that are part of the ajax postback (why doing a
> decode on not effected components?).
>
> we do it like:
> uiViewRoot.invokeOnComponent(context, clientId, callback);
>
> where the *callback* is something like:
> static private class UpdateModelValuesCallback implements ContextCallback
> {
> public void invokeContextCallback(FacesContext context,
> UIComponent target)
> {
> target.processUpdates(context);
> }
> }
>
> usually these *optimized* lifecycles offer optimization for these phases:
> -ApplyReqValue
> -processValidation
> -UpdateModel
>
> not on:
> -Invoke App
> -RenderResponse
>
> For these, we just do a delegate back to the standard (default) behavior,
> like:
> viewRoot.processApplication(context);
>
> So now.... the processXyz (like processUpdates()) is only! called on
> the "ajax components"!
> (Tobago does that in a similar way. They *fake* invokeOnComponent,
> since that lib is JSF 1.1 based)
>
> What does that mean, when submitting an ajax postback (maybe triggered
> by <inputText autoSubmit="true" />) ?
> The (to uiviewRoot) attached PL is only invoked for these phases:
> -Invoke App
> -RenderResponse
>
> Why?
> The big problem (IMO) is, that the "PhaseListener(s) attached to the
> current (per view) UIViewRoot" are *triggered* by the processXyz() of
> UIViewRoot itself (and encodeEnd and encodeBegin for RenderResponse phase).
> So... when only invoking them on the effected "ajax components" the
> before/afterPhase is never triggered (for the optimized phase).
>
> The optimized lifecycle could get the attached PhaseListeners, in case
> there where a public getPhaseListeners() method on UIViewRoot.
> I am wondering why there is none ? Simply forgotten?
>
> Please note, that (also since JSF 1.2) you can register methodExpression
> like:
> <f:view beforePhase="#{methodExpression}"
> afterPhase="#{otherMethodExpression}">
>
> but... there is acutally a public getBeforePhaseListener() and a
> getAfterPhaseListener() as well.
> So a optimized lifecycle could get these MethodExpressions.
>
> What is your take on that?
>
> Thanks for reading,
> Matthias
>
> --
> Matthias Wessendorf
>
> further stuff:
> blog: http://matthiaswessendorf.wordpress.com/
> sessions: http://www.slideshare.net/mwessendorf
> mail: matzew-at-apache-dot-org
>
--
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