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
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