Problem with custom tag using TagExtraInfo

Question

          Hi,
          I have a tag that create a Java variable using TEI. The scope of this
          variable is driving me crazy. The problem is hard to describe, so the
          email is a bit long - stay with me...
          <pre:setvar id="foo" value="test" /> create a Java variable
          named "foo", which has String value "test". I can use "foo" like this in
          the page later: <%= foo %>.
          Now, if I call setvar twice with same id:
          <pre:setvar id="foo" value="test" />
          <pre:setvar id="foo" value="another-test" />
          This is still ok. By checking the compiled Java file, the first call
          declare the var, the second call just use it without creating it again:
               //first call
               String foo=null;
               foo="test";
               //second call
               foo="another test";
          Now the problem comes when the frist call is in "if" statement (code is not
          useful, only for demostration):
          <% if (1>0) { %>
               <pre:setvar id="foo" value="test" />
          <% } %>
          <pre:setvar id="foo" value="another-test" />
          The compiled code looks like:
               if (1>0) {
                    //first call
                    String foo=null;
                    foo="test";
               //second call
               foo="another test";
          Variable foo is out of scope at the second call! (BTW, I can workaround this by
          adding another <pre:setvar id="foo" value="" /> before the "if".)
          Is it a fault in JSP specification? Or a problem when WebLogic implements TEI?
          Any idea?
          Thanks,
          -- Jin
          

Answer 1

I encountered the same problem in our environment. I did the same thing as
          James. Simply re-initialize all variables in the do end tag.
          Also, with the nested tags you use you may also need to implement cloneable
          in the inner tag if the outer tag keeps references to all the inner tag
          instances.
          For instance if the outer tag kept a vector of references to the inner tag,
          then you would need to use clone() on the inner tag before adding it to the
          vector.
          "James Lynn" <[email protected]> wrote in message
          news:3af05d29$[email protected]..
          > > But
          > > with WL 6.0, the cell tag handler reuse the same instance each time the
          > cell tag
          > > is called and the member field is not reset
          >
          > I had the same problem. As a work around, I reinitialize everything in my
          > doEndTag() method and it works.
          >
          >
          > --
          > James Lynn - Lead Software Architect
          > Oakscape - Java Powered eBusiness Solutions <http://www.oakscape.com/>
          >
          >