Sorry I forgot that a FacesContext instance is only available if a jsf
request is actually processed.
But you have still access in the context listener to the configured
jsf application instance. I really suggest you to use something which
allows you to initialize a custom action listener only one time. If
you do it in a session listener you will end up with a new
actionlistener impl everytime a session starts.
To get an instance of the JSF Application class use the FactoryFinder class:
ApplicationFactory appFactory =
(ApplicationFactory)FactoryFinder.getFactory(FactoryFinder.APPLICATION_FACTORY)
Application app = appFactory.getApplication();
this is the way how we do it if we must wrap some core functionality
in jsf and still being implementation independent.
2005/11/10, Tim Davies <[EMAIL PROTECTED]>:
> Im using the latest release of MyFaces.
>
> Im not really sure what to advise. I had it working okay with this
> approach but I dont have the code anymore unfortuately so cant check back.
>
> Not much more I can suggest really, sorry.
>
> Robert Parsons wrote:
>
> > Hi,
> >
> > I tried doing what you suggested and obtaining the existing
> > ActionListener on construction of mine, but:
> >
> > FacesContext.getCurrentInstance();
> >
> > is returning null, so I cant access access the faces application. Are
> > you using MyFaces or the RI?
> >
> > Thanks,
> > -Robert.
> >
> > Tim Davies wrote:
> >
> >> Seems a reasonable question but this does not seem to be the case. If
> >> you initialise your reference to the original ApplicationListener in
> >> your constructor then I think you should be fine.
> >>
> >> I would give it a go and see. This was working fine for me but I
> >> admit I didnt look too deeply under the covers.
> >>
> >>
> >> Robert Parsons wrote:
> >>
> >>> Yes,
> >>> But if you do it in the faces-config how do you wrap the default
> >>> action listener? Wouldnt your action listener replace the default
> >>> one before you get a chance to wrap it?
> >>>
> >>> Thanks,
> >>> -Robert
> >>>
> >>>
> >>> Tim Davies wrote:
> >>>
> >>>> Sorry that was a bit vague.
> >>>>
> >>>> Mathias suggested initialising the custom ApplicationListener in a
> >>>> ServletContextListener object. However if this is registered as a
> >>>> listener in web.xml then its contextInitialized() method will be
> >>>> called before the FacesContext is initilised and so it will not work.
> >>>>
> >>>> I think that faces.config is probably the best place to set this as
> >>>> then you know that it will always be set when faces is used and do
> >>>> not have to worry about maintaining it in your own code somewhere.
> >>>>
> >>>>
> >>>> Robert Parsons wrote:
> >>>>
> >>>>> Thanks for the quick reply.
> >>>>>
> >>>>> I thought you said that at context initialisation the FacesContext
> >>>>> was not initialised? I have not tried it myself however. I decided
> >>>>> to wrap the handler when the first session is created instead. Is
> >>>>> there a better place to create the wrapper?
> >>>>>
> >>>>> Thanks,
> >>>>> -Robert.
> >>>>>
> >>>>> Tim Davies wrote:
> >>>>>
> >>>>>> Mathias wrote a version that will do this earlier in this thread.
> >>>>>>
> >>>>>> Basically you need to get and store a reference to the original
> >>>>>> actionlistener in your actionlistener. Then in your processaction
> >>>>>> method you perform your work or set up your try catch block and
> >>>>>> then call processAction on the original actionlistener.
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> Robert Parsons wrote:
> >>>>>>
> >>>>>>> I'm a little confused. If I register it in the faces-config.xml,
> >>>>>>> how do I then pass on the action to the existing action
> >>>>>>> listener? (the one that actually does something) Or is that not
> >>>>>>> how it works. I can only find information on action listeners
> >>>>>>> for components, not global ones like this.
> >>>>>>>
> >>>>>>> Tim Davies wrote:
> >>>>>>>
> >>>>>>>> Just as an update to this, if you want to register your own
> >>>>>>>> ActionListener then you can do so by adding the following
> >>>>>>>> element to your faces-config.xml file.
> >>>>>>>>
> >>>>>>>> <application>
> >>>>>>>> <action-listener>
> >>>>>>>> com.example.MyActionListener
> >>>>>>>> </action-listener>
> >>>>>>>> </application>
> >>>>>>>>
> >>>>>>>> I tried it in the context listener but the FacesContext will
> >>>>>>>> not have been initialised at the point when it is run.
> >>>>>>>>
> >>>>>>>> Thanks for the tips on this though. Has proved interesting.
> >>>>>>>>
> >>>>>>>> Tim
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> Mathias Brökelmann wrote:
> >>>>>>>>
> >>>>>>>>> the actionlistener which is accessed/registered through
> >>>>>>>>> Application is
> >>>>>>>>> responsible for handling actions.
> >>>>>>>>>
> >>>>>>>>> 2005/11/6, Mike Kienenberger <[EMAIL PROTECTED]>:
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>> That's good to know. Does it work for action as well as
> >>>>>>>>>> actionListener?
> >>>>>>>>>>
> >>>>>>>>>> On 11/6/05, Mathias Brökelmann <[EMAIL PROTECTED]>
> >>>>>>>>>> wrote:
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>> It´s quite easy to change the handling for invoking action
> >>>>>>>>>>> methods.
> >>>>>>>>>>> Simply wrap existing ActionListener Implementation of
> >>>>>>>>>>> processAction
> >>>>>>>>>>> with an try and catch block:
> >>>>>>>>>>>
> >>>>>>>>>>> FacesContext context = FacesContext.getInstance();
> >>>>>>>>>>> final ActionListener actionListener =
> >>>>>>>>>>> context.getApplication().getActionListener();
> >>>>>>>>>>> ActionListener wrappedActionListener = new ActionListener()
> >>>>>>>>>>> {
> >>>>>>>>>>> public void processAction(ActionEvent actionEvent) throws
> >>>>>>>>>>> AbortProcessingException
> >>>>>>>>>>> {
> >>>>>>>>>>> try
> >>>>>>>>>>> {
> >>>>>>>>>>> actionListener.processAction(actionEvent);
> >>>>>>>>>>> }
> >>>>>>>>>>> catch(Throwable t)
> >>>>>>>>>>> {
> >>>>>>>>>>> // do generic action exception handling here
> >>>>>>>>>>> }
> >>>>>>>>>>> }
> >>>>>>>>>>> }
> >>>>>>>>>>> context.getApplication().setActionListener(wrappedActionListener);
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>> You can implement it in a
> >>>>>>>>>>> javax.servlet.ServletContextListener.contextInitialized()
> >>>>>>>>>>> method. and
> >>>>>>>>>>> register the listener in your web.xml file.
> >>>>>>>>>>>
> >>>>>>>>>>> 2005/11/5, Mike Kienenberger <[EMAIL PROTECTED]>:
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>>> It doesn't appear that there's an easy way to do this.
> >>>>>>>>>>>> The events are triggered from UIComponentBase.broadcast()
> >>>>>>>>>>>> which calls
> >>>>>>>>>>>> each event.processListener() method which calls
> >>>>>>>>>>>> ActionListener.processAction() which calls
> >>>>>>>>>>>> methodBinding.invoke().
> >>>>>>>>>>>>
> >>>>>>>>>>>> Ideally, you'd want to specify a custom
> >>>>>>>>>>>> methodBinding.invoke() that
> >>>>>>>>>>>> wrapped the error for you. Facelets does things
> >>>>>>>>>>>> differently -- maybe
> >>>>>>>>>>>> there's a way to create alternate MethodBinding rules for
> >>>>>>>>>>>> ActionSources which create your subclass of MethodBinding
> >>>>>>>>>>>> rather than
> >>>>>>>>>>>> the default MethodBinding instances. You could try asking
> >>>>>>>>>>>> about that
> >>>>>>>>>>>> on the facelets mailing list.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Another possiblity is to use aspect-oriented-programming
> >>>>>>>>>>>> (AOP) to
> >>>>>>>>>>>> intercept methodBinding.invoke(). However, I don't use
> >>>>>>>>>>>> AOP, so I
> >>>>>>>>>>>> can't tell you anything beyond that it appears to do what
> >>>>>>>>>>>> you need.
> >>>>>>>>>>>>
> >>>>>>>>>>>> On 11/5/05, Robert Parsons <[EMAIL PROTECTED]> wrote:
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>> Hi,
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> thanks for the reply. the wording of my question was a
> >>>>>>>>>>>>> little bit off. I
> >>>>>>>>>>>>> was looking for an automatic way for Exceptions that were
> >>>>>>>>>>>>> thrown in any
> >>>>>>>>>>>>> action method to automatically be added as a message
> >>>>>>>>>>>>> (instead of the
> >>>>>>>>>>>>> horrible error screens i get from facelets at the moment).
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> The only other option other than an automatic method would
> >>>>>>>>>>>>> be to wrap a
> >>>>>>>>>>>>> try-catch around all the code of every action I have and
> >>>>>>>>>>>>> generate a message
> >>>>>>>>>>>>> when an exception is caught. Sounds like that might have
> >>>>>>>>>>>>> to be the way I do
> >>>>>>>>>>>>> it.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Thanks anyway,
> >>>>>>>>>>>>> -Robert.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Volker Weber wrote:
> >>>>>>>>>>>>> Hi,
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> you can add a Message to FacesContect.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> See:
> >>>>>>>>>>>>> http://java.sun.com/j2ee/javaserverfaces/1.1_01/docs/api/javax/faces/context/FacesContext.html#addMessage(java.lang.String,%20javax.faces.application.FacesMessage)
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> regards
> >>>>>>>>>>>>> Volker
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Robert Parsons wrote:
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Hi,
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Is there an easy way to make exceptions thrown by action
> >>>>>>>>>>>>> methods (on
> >>>>>>>>>>>>> backing beans) to generate messages? Or would this only be
> >>>>>>>>>>>>> possible by
> >>>>>>>>>>>>> modifying the MyFaces code.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Thanks heaps,
> >>>>>>>>>>>>> -Robert
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>> --
> >>>>>>>>>>> Mathias
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>> Mathias
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>
> >>>>>>>
> >>>>>>
> >>>>>
> >>>>
> >>>
> >>
> >
>
> --
> Tim Davies
> Analyst Developer
>
> KTS PLC: Service you can bank on
> 8th Floor, Finsbury Tower,
> 103-105 Bunhill Row,
> London EC1Y 8TY
> tel: +44 (0)20 7256 2300
> fax: +44 (0)20 7256 2301
>
> email: [EMAIL PROTECTED]
> web: http://www.ktsplc.com
>
>
--
Mathias
