Re: Jsp compilation of nested custom tags (porting from weblogic 6 to tomcat 4.0.3)

[Kin-Man Chung <Ki...@Eng.Sun.COM>]

I assume that lOffset is a scripting variable defined either in a <variable>
element of a tld, or in a TagExtraInfo, and that its declaration (in the
generated java file) is a result of the compiler trying to do its
synchronization with the pagecontext attribute of the same name.

If so, what is the scope of this variable?  Is it NESTED or AT_BEGIN?

I can see how the current Jasper implementation can be problematic,
There are two problems here.

First, if the scope is AT_BEGIN, then the scope of the variable should
remain defined until the end of the page, and the current implementation
actually make it unavailable after the end of the tag, which is wrong.

Second, if the tags are nested, as is your case here, then redclaring
it in the nested block would be illegal Java.

Can you file a bug report in bugzilla for this?  It would help if you
can also include a small test case, so that fixes can be verified.

Thanks.


> Date: Thu, 06 Jun 2002 18:54:11 -0400
> From: Pete Gordon <PG...@fourthchannel.com>
> Subject: Re: Jsp compilation of nested custom tags (porting from weblogic 6 to 
tomcat 4.0.3)
> To: Tag Libraries Developers List <ta...@jakarta.apache.org>
> Cc: tomcat-dev@jakarta.apache.org
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> 
> Thanks, Shawn.
> 
> Let me summarize for the tomcat-dev list.  I have an existing 
> application with custom tags that runs on weblogic 6, when porting it 
> over to Tomcat I now am running into an error where the generated java 
> from a jsp with self nested tags will not compile, the code generated 
> from jspc simulates the HelloWorld sample below, which is not valid java
> 
> code--it would be valid in C, but that's another story.
> 
> The first htmlGlobalAttribSearch$jsp.java compile error is line 198, 
> variable lOffset is already defined.  There are several (19) more errors
> 
> like this that are also outputed from trying to compile the $jsp.java 
> file that I have attached.
> 
> public class HelloWorld{
> 	public static void main(String args[]){
> 		do{
> 			int i = 5;
> 			do{
> 				int i=10;
> 			}while(false);
> 		}while(false);
> 	}
> }
> 
> Tomorrow, I will try to create a minimal nested tag example and see if I
> 
> can duplicate the problem.  Unless someone is aware of this problem 
> already, and can save me the effort.
> 
> Thanks,
> Pete Gordon
> 
> 
> 
> On Thursday, June 6, 2002, at 03:03 PM, Shawn Bayern wrote:
> 
> > Hi Pete,
> >
> > If this is a Tomcat bug, it would be better to mail tomcat-dev about
> it 
> > or
> > to submit a Tomcat bug report in Apache's Bugzilla
> > (http://nagoya.apache.org/bugzilla).  I'd be happy to take a look at
> it
> > myself, but it's difficult to identify the problem in a large compiled
> > servlet.  (I can't attempt to compile it myself since it depends on
> some
> > custom classes not included.)  If you could post the compilation
> error,
> > that'd definitely help us determine whether it looks like a Tomcat bug
> 
> > or
> > not.
> 
> 
> 
> From: Pete Gordon <PG...@fourthchannel.com>
> Date: Thu Jun 06, 2002  02:32:06 PM US/Eastern
> To: 'Tag Libraries Developers List' <ta...@jakarta.apache.org>
> Subject: Jsp compilation of nested custom tags (porting from weblogic 6 
> to tomcat 4.0.3)
> Reply-To: "Tag Libraries Developers List" <taglibs-
> dev@jakarta.apache.org>
> 
> There is a problem with compiling the genenerated java code
> (htmlGlobalAttribSearch$jsp.java) it tells me that variables have
> already
> been defined.  I have compiled the source file and even created a test
> HelloWorld.java to test it.  It is correct variables have already been
> defined, which we found strange as far as the scope variables were
> accessible, see the code below....
> 
> public class HelloWorld{
> 	public static void main(String args[]){
> 		do{
> 			int i = 5;
> 			do{
> 				int i=10;
> 			}while(false);
> 		}while(false);
> 	}
> }
> 
> The JSP page has several nested custom tags (the same tags) and this is
> working on weblogic 6.  But the generated java file from tomcat/jasper 
> does
> not compile.  The problem is the <fci:collection> tag being nested a few
> times within itself.  See the JSP below.  I think this is a problem with
> 
> the
> jspc generated java code.  Am I way off base?
> 
> Thanks,
> Pete Gordon
> 
> <%@ taglib uri="fciTagLib.tld" prefix = "fci" %>
> <%@ page import="com.fci.arch.service.*"%>
> 
> <form action="<fci:get resource="site"/>" method="GET" id=form1 
> name=form1>
> <input type="hidden" name="action" 
> value="catalogActions.globalParametric">
> <input type="hidden" name="searchPerfomed" value="true">
> 
> <table width="<fci:get resource="catNavWidth"/>" cellspacing="2"
> cellpadding="2" border="0">
> <tr>
> 	<td><fci:get resource="Parametric.Instructions"/></td>
> </tr>
> <fci:collection name="globalAttributeSearchDetail">
> 	<fci:collection name="pSearchAttributeType" cacheLevel="none">
> 	<tr>
> 		<td>
> 			<fci:get resource="Prefix.Content"/>
> 			<fci:element name="Name"/>
> 			<br>
> 			<select name="<fci:element name="Name"/>">
> 				<option value="~all~">all</option>
> 				<fci:collection
> name="globalAttributeValues"
> cacheLevel="none">
> 					<% String value =
> ((Agent)pageContext.getAttribute("pSearchAttributeType.currentDO")).getP
> rope
> rty("Name").toString(); %>
> 					<fci:element name="Value"
> format="option" compare="<%= value %>"/>
> 				</fci:collection>
> 			</select>
> 			<fci:get resource="Suffix.Content"/>
> 		</td>
> 	</tr>
> 	</fci:collection>
> </fci:collection>
> <fci:nonempty collection="globalAttributeSearchDetail">
> <tr>
> 	<td align="left">
> 		<br><fci:get resource="Button.AttributeSearch"/>
> 	</td>
> </tr>
> </fci:nonempty>
> </table>
> </form>
> 
> 
> 
> 
> <File attached: htmlGlobalAttribSearch$jsp.java>--
> 
>  
> 


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