Hi Yannick,
t:saveState performs two actions:
At the very end of the rendering phase, it looks up the object specified
by its value attribute and serializes it.
During the "restore view" phase, it deserializes its associated object,
then evaluates its "value" attribute and assigns the recreated object to it.
I don't understand your statements about having "to modify the saveState
component". You modify the object that the saveState component points
to, not the saveState component itself. And in general that's trivial.
However from your description below, it looks like you're just trying to
do a basic master/detail screen. In this case, you don't need saveState
at all. Sorry if the reason why you want to use saveState here was given
at the start of this thread; I haven't got that easily available.
However for basic master/detail stuff, there is an example in the
"examples" directory of the MyFaces download that you may wish to look
at; it doesn't need saveState at all.
Regards,
Simon
PS: aargh, I hate top-posting!
Yannick Le Teigner wrote:
Simon,
The problem I face with the saveState component, is that when I place it
on the master (1st) page, it is, as expected, initialized with no value
(because the user has yet to click on a row in the datatable to edit a
user/item.)
Once the user click on a row, the detail page is displayed. But the
BackingBean is reloaded from the saveState component, and is set as
empty (as it was on the master page) -- and not initialized with the
data from the row the user has clicked on.
What I would need is somehow to modify the saveState component before
the detail page is displayed so that I can modify the backingbean inside
and put one correctly initialized (corresponding to the row the user has
clicked on).
This seems like a basic app, but I cannot get around it without using
session scoped bean. I would be very welcome if anyone could show me
some code with request scoped beans achieving the same results.
Thanks!
> <t:saveState> is the correct tag to use when you want to avoid
session-scoped managed
> beans.
>
> I don't know why you have that command-link code; nothing like this
is necessary to use
> t:saveState. If you wish to preserve the state of an entire managed
bean, then do:
>
>Master page:
> <t:saveState value="#{myBackingBean}"/>
>
> Detail page:
> <t:saveState value="#{myBackingBean}"/>
>
> On first visit to the master page, there is no saved state to
restore, so a default instance
> of that bean is created. When the page is serialized after rendering,
the bean's state is
> stored.
>
> When either the master or detail page is visited thereafter, the
saved object is recreated
> from the saved state, and #{myBackingBean} is set to be a reference
to the restored
> object.
>
> You can also save just specific fields of a bean via:
> <t:saveState value="#{myBackingBean.someProperty}"/>
>
>Regards,
>
>Simon
