Erwin DSouza wrote:
> Hi Hans,
>
> Sorry to bother you again with this old thread, but I
> hadn't thought of all the implications of your
> suggestion until now.
> I was asking about how to avoid attribute-name clashes
> in nested tags, and you suggested using:
>
>> The easiest solution is to let the page athor specify
>> the
>> variable name:
>>
>> <!-- Create variable "foo" -->
>> <mytags:foo var="foo">
>> <!-- Create variable "bar" -->
>> <mytags:foo var="bar">
>> ...
>> </mytags:foo>
>> </mytags:foo>
>>
>> If you don't need to access the value through a
>> scripting...
>
>
>> If you *do* need to access the value through scripting
>> code,
>> you can tell the container to use the "var" attribute
>> value for
>> the scripting variable using either a TagExtraInfo
>> class (JSP 1.1
>> and JSP 1.2) or using the <variable> element in the
>> TLD (JSP 1.2).
>
> I *do* need to access the attributes in scripting code.
> But how do I add the new variable dynamically to the
> TagExtraInfo class? How does it help if I add "var" to
> the TEI?
> (I need foo and bar to be variables that I can access
> in my scripting code)
> Is this possible?
Yes it is. As to how, read a book, like mine :-) Just kidding,
even though I do recommend that anyone doing JSP development
read at least the specification. There are many things that you
just can't figure out just by looking at the APIs.
Anyway, here's a TEI that tells the container to create a variable
with the name supplied by the page author as the "id" attribute
value (you should use "id" when you create a scripting variable,
following the convention from <jsp:useBean>; "var" is a name convention
established by JSTL for variables saved only in a JSP scope):
public class MyTagTEI extends TagExtraInfo {
public VariableInfo[] getVariableInfo(TagData data) {
return new VariableInfo[] {
new VariableInfo(data.getAttributeString("id"),
"com.mycompany.SomeType",
true,
VariableInfo.AT_END)
}
}
}
The variable is of type "com.mycompany.SomeType" and made available
after the closing tag for the action element (AT_END).
If you use a JSP 1.2 container, you can replace the TEI with this
declaration in the TLD:
<tag>
<name>myTag</name>
<tag-class>com.mycompany.MyTag</tag-class>
<variable>
<name-from-attribute>id</name-from-attribute>
<variable-class>com.mycompany.SomeType</variable-class>
<declare>true</declare>
<scope>AT_END</scope>
<description>This variable contains ...</description>
</variable>
...
</tag>
Hans
--
Hans Bergsten [EMAIL PROTECTED]
Gefion Software http://www.gefionsoftware.com
JavaServer Pages http://TheJSPBook.com
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