How to communicate between the child and parent tag

Hi All,
I want to pass the child tags attribute value to the parent tag class. for example
Line1 <c:data>---- DataTag.class
Line2 <d:show valid="true"/>
Line3 </c:data>
I want to get the child tags attribute valid's value "true"(Static value) to my parent tag DataTag.class before it comes to line 2
Depends upon the value i will do some process.

before it comes to line 2

You mean before the nested tag gets evaluated ?

yes... before evaluating the child tag...

That's not possible then. (I don't think it is)

Thats not possible, why do you want to do that?

You can have the attribute to the outer tag.
Can you please explain in details what are you trying to do?