FindComponent(..) problem. -repost.

Question

I'm posting this issue again as a separate thread as the subject was little off the topic.
<original post>:
I went through the JavaDocs but still could not figure out how findComponent really works. Here's an example:
<f:view>
<h:form id="Home" >
<xx:comp1 id="id1" ...>
<xx:comp2 parentID="id1"/>
</xx:comp1>
where comp1 and comp2 are two custom components. Now I'd like comp2 to find out about comp1 and hence the parentID attribute. In comp2 i've code like this:
facesContext.getViewRoot().findComponent( parentID ); where parentID is the string containing the id value of comp1 as shown above.
However I get null.
The reason I'm doing this is to be able to have alternate jsp syntax for these components, something like this:
<f:view>
<h:form id="Home" >
<xx:comp1 id="id1" .../>
<xx:comp2 parentID="id1"/>
I guess this is the same approach as <h:message for="blah".. /> and any of the nested component tags like <h:selectmany.. >
<f:selectitem...>
</h:selectmany..>
Maybe I'm misunderstanding some fundamental concepts about referencing other components in the same tree. Can someone please enlighten me on this?
Thanks - AM
Re: Accessing an UIComponent object from a .java
Author: w.drai
In Reply To: Re: Accessing an UIComponent object from a .java Apr 18, 2004 7:36 PM
Reply 6 of 8
You should call findComponent from the comp2 component itself : comp2.findComponent(parentId)
If you call findComponent from the viewRoot, you have to supply the whole component path (i.e. with all the NamingContainers). In your example, that would "Home:id1".
Re: UIComponent.findComponent(..) -- help!
Author: arun_manta
In Reply To: Re: Accessing an UIComponent object from a .java Apr 19, 2004 8:47 AM
Reply 7 of 8
You should call findComponent from the comp2 component
itself : comp2.findComponent(parentId)
If you call findComponent from the viewRoot, you have
to supply the whole component path (i.e. with all the
NamingContainers). In your example, that would
"Home:id1".Thanks for your reply, but this doesnt work either. - It still returns null. I have tried the following cases:
Comp2.findComponent(parentId) from Comp2 tag handler -----> returns null.
Comp2.findComponent(parentId) from Comp2 (decode, encodeEnd etc.. ) -----> returns null.
Comp2.findComponent("Home:"+parentId) -- returns null.
However this works:
call getParentUIComponentTag() from Comp2 tag -> which returns me the Comp1 tag handler.
call getComponentInstance() on the Comp1 tag handler -> returns the Comp1 component.
( Now I have the parent component ) but this restricts us to using nested tags only.
AM
Re: UIComponent.findComponent(..) -- help!
Author: arun_manta
In Reply To: Re: UIComponent.findComponent(..) -- help! Apr 19, 2004 9:45 AM
Reply 8 of 8
You should call findComponent from the comp2component
itself : comp2.findComponent(parentId)
If you call findComponent from the viewRoot, youhave
to supply the whole component path (i.e. with allthe
NamingContainers). In your example, that would
"Home:id1".Thanks for your reply, but this doesnt work either. -
It still returns null. I have tried the following
cases:
Comp2.findComponent(parentId) from Comp2 tag
handler -----> returns null.
Comp2.findComponent(parentId) from Comp2
(decode, encodeEnd etc.. ) -----> returns null.
Comp2.findComponent("Home:"+parentId) -- returns null.
However this works:
call getParentUIComponentTag() from Comp2 tag -> which
returns me the Comp1 tag handler.
call getComponentInstance() on the Comp1 tag handler
-> returns the Comp1 component.
( Now I have the parent component ) but this restricts
us to using nested tags only.
AMOops. well this one works:
Comp2.findComponent("Home:"+parentId)
but then I have to know the form ID within the component. Also if I do not specify the form Id in the jsp, i.e.
<h:form>
</h:form> I have the same problem.

Answer 1

Really strange. We use findComponent(id) in some custom renderers with no problem.
Is comp2 the UIComponent or the UIComponentTag in your examples ?
If this is the tag handler, you could try comp2.getComponentInstance().findComponent(parentId)