Re: [jsr-314-open] Should the ViewDeclarationLanguage be responsible to indicate if a viewId can be created?

Hi Leonardo, was this ever settled? Did you get the feedback you need? Did you open an issue? best regards, Martin On Tue, Sep 14, 2010 at 3:30 AM, Leonardo Uribe <lu4242(a)gmail.com&gt; wrote: > Hi > > The current algorithm to check if a view with a specific viewId does not > allow to add or extends a new ViewDeclarationLanguage using a new > prefix/extension. > > This issue is related to > > https://issues.apache.org/jira/browse/MYFACES-2628 Facelets ResourceSolver > can't work > > and > > https://javaserverfaces.dev.java.net/issues/show_bug.cgi?id=1567 > > The problem resides on a "hidden" requeriment for Restore View Phase > algorithm, that is ignored silently. On mojarra, this is the code on > MultiViewHandler.getViewDeclarationLanguage: > > public ViewDeclarationLanguage getViewDeclarationLanguage(FacesContext > context, > String viewId) > { > > String actualViewId = derivePhysicalViewId(context, viewId, false); > return vdlFactory.getViewDeclarationLanguage(actualViewId); > > } > > Now on myfaces is this: > > @Override > public ViewDeclarationLanguage getViewDeclarationLanguage( > FacesContext context, String viewId) > { > // return a suitable ViewDeclarationLanguage implementation for the > given viewId > return _vdlFactory.getViewDeclarationLanguage(viewId); > } > > The difference is subtle, but very, very important. This method is called > from many locations, but only once (from RestoreViewPhase) it is passed the > "raw" viewId. To "derive" the physical viewId it is required to know if > prefix or suffix mapping is used and if suffix mapping is used, try to check > if a view "resource" exists or not with different derived ids with the > extensions configured ".xhtml .jsp". > > javax.faces.view.facelets.ResourceResolver documentation says this: > > "... Provide a hook to decorate or override the way that Facelets loads > template files. A default implementation must be provided that satisfies the > requirements for loading templates as in Pre-JSF 2.0 Facelets ..." > > So, in theory it is possible to override ResourceResolver interface and > serve resources from a different location. But the algorithm in > MultiViewHandler.derivePhysicalViewId does not take into account this > interface, so it try to check if the view "resource" exists on the same > location and fails. > > The solution proposed is add a method on ViewHandler, > ViewDeclarationLanguageFactory and ViewDeclarationLanguage called: > > public boolean existsViewId(String viewId) > > So the VDL can indicate if a viewId exists or not. In this way, on Facelets > VDL we can check if a viewId exists using the ResourceResolver instance. It > is curious that ViewDeclarationFactory implementation has some methods that > indicate if a vdl can handle a viewId or not (it is not the same, but > similar). I'm not done too much work on this issue, but it could be good to > take a look at this one. It could be good to open an issue on the spec for > this one too (if no objections I'll open an issue for this one, but better > to ask first). > > Suggestions are welcome. > > regards, > > Leonardo Uribe > -- http://www.irian.at Your JSF powerhouse - JSF Consulting, Development and Courses in English and German Professional Support for Apache MyFaces