Matt Blum wrote:
The Faces servlet does a forward by default, so all you need to do is
take out the redirect tag from your navigation rule, and that's what
will happen.
Well, ok. But I guess I'm just not understanding where the code to put
the messages in the session would be in that case. Would it have to be
in the JSP page?
Rather than do something like that could I instead save the messages to
the session after the render response phase with a phase listener and
then restore them before the restore view phase with another?
This should work assuming that when a <h:messages /> element is
encountered it dequeues messages it displays, otherwise the messages
will just continually be added to the session and displayed over and
over again. As long as this is the case, I don't see a reason this
wouldn't work, what do you think?
Rich
You can fix the reload issue with a token, which is a server-generated
value stored submitted with the form that's checked on submission and
invalidated, so that if the form is re-submitted, the server will
detect it. This would allow you to, if the form is resubmitted,
redirect the user to an error page or somesuch (or do anything else
you wanted to do). This is something you should do anyway, because
even if you do a redirect the user could always use the browser's back
button and resubmit the form.
Craig McClanahan has included an excellent JSF-friendly implementation
of this in Shale. See the javadocs here:
http://people.apache.org/~craigmcc/shale-core-javadocs/org/apache/shale/component/Token.html
<http://people.apache.org/%7Ecraigmcc/shale-core-javadocs/org/apache/shale/component/Token.html>
I'm not worried about the user hitting the back button and resubmitting
the form. They'd have to actually want to go back to the form and
resubmit it. And that might be a perfectly valid use-case for some
people, using their browsers navigation rather than the site navigation.
On 6/14/05, *Richard Wallace* <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>> wrote:
Matt Blum wrote:
> This has been asked a number of times on this mailing list.
>
> The messages are stored in the request object, so you're losing them
> with the redirect. You should probably use a forward, unless
there's
> a truly compelling reason to use a redirect. If you must use a
> redirect (say, so users can bookmark the resulting page), you'll
have
> to first forward to something that will extract the messages
from the
> request and put them in the session, and then do the redirect
you were
> trying to do in the first place.
>
> -Matt.
The main purpose is to avoid the user being able to hit the browsers
reload button and having the form submitted a second time and a
duplicate entry being created in the database. How would I use a
forward? I'm not exactly sure how to do that. Is that in the
navigation rule or somewhere else? Will that accomplish what I need?
Thanks,
Rich
>
> On 6/14/05, *Richard Wallace* <[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>
> <mailto:[EMAIL PROTECTED]
<mailto:[EMAIL PROTECTED]>>> wrote:
>
> Hello again,
>
> This should be a pretty simple problem. In the CRUD app
that I'm
> using
> as a proof-of-concept for using JSF here at work I've got
everything
> working and think I'm starting to understand some of the
nuances of
> JSF. But one thing that is not working as I expected is the
> handling of
> messages.
>
> When a user creates an object (say a contact), after filling
out the
> form and hitting submit they are redirected to the contact list
> page via
> the navigational rule:
>
> <navigation-rule>
> <from-view-id>/contact/add.jsp</from-view-id>
> <navigation-case>
> <from-action>#{contactHandler.saveContact
}</from-action>
> <from-outcome>success</from-outcome>
> <to-view-id>/contact/list.jsp</to-view-id>
> <redirect/>
> </navigation-case>
> </navigation-rule>
>
> That works and all, but in the contactHandler.saveContact()
method
> I am
> also adding an informational message that the contact was saved
> just to
> give the user a warm fuzzy feeling. So, in my list.jsp page I
> have the
> <h:view> followed immediately by <h:messages />. But nothing is
> displayed when the user is redirected to this page after
successfully
> adding a contact. I know I'm adding it right because I'm
doing it
> the
> same way on the /contact/edit.jsp page which doesn't
redirect after a
> successful edit.
>
> The only things I can think of that would cause this is that
JSF is
> processing the /contact/add.jsp page before doing the
redirect, and
> there is a <h:messages /> tag in there in case there is some
> validation
> error or some other problem. But that's just a guess.
>
> The other possibility to me is that the messages are somehow
page
> specific, so a message generated on one page won't show up on
> another.
> In which case my question is how do I get around this?
>
> Could it maybe have something to do with the backing bean that
> generates
> the message being request scoped rather than session scoped?
>
> Once again, thanks for the help
> Rich
>
>
