DO NOT REPLY TO THIS EMAIL, BUT PLEASE POST YOUR BUG 
RELATED COMMENTS THROUGH THE WEB INTERFACE AVAILABLE AT
<http://nagoya.apache.org/bugzilla/show_bug.cgi?id=12365>.
ANY REPLY MADE TO THIS MESSAGE WILL NOT BE COLLECTED AND 
INSERTED IN THE BUG DATABASE.

http://nagoya.apache.org/bugzilla/show_bug.cgi?id=12365

Contribution of Struts-EL library: Struts with JSTL EL attributes

           Summary: Contribution of Struts-EL library: Struts with JSTL EL
                    attributes
           Product: Struts
           Version: 1.1 Beta 2
          Platform: Other
        OS/Version: Other
            Status: NEW
          Severity: Enhancement
          Priority: Other
         Component: Custom Tags
        AssignedTo: [EMAIL PROTECTED]
        ReportedBy: [EMAIL PROTECTED]


This is a contribution to the Struts library that I've been working on for a
while.  It consists of a tag library that provides the same functionality as the
Struts tag library, but which uses the JSTL EL engine for attribute values,
instead of using rtexprvalues.  I had wanted to work on this for a while, and
Craig McClanahan told me this would be a good thing to build as a contributed
library, so here it is.  Note that it requires JSP 1.2, as there are elements in
the JSTL which require JSP 1.2.  I will enclose the README.txt file here inline,
but I will attach the "tar.gz" of the entire distribution as an attachment.
-----------------------------------
 Struts-EL extension
 ===================

Introduction
------------

This subproject is an extension of the Struts tag library.  Each JSP custom tag
in this library is a subclass of an associated tag in the Struts tag library.
One difference is that this tag library does not use "rtexprvalues", it uses
the expression evaluation engine in the JSP Standard Tag Library (version 1.0)
to evaluate attribute values.

In addition, some of the Struts tags were not ported to this library, as it was
determined that their functionality was entirely supplied by the JSTL.  These
particular Struts tags, and the reason for their non-porting will be described
in the documentation for this library.

In order to fully understand the correct utilization of this library, you must
understand the use and operation of the Struts tag library, and the use and
operation of the JavaServer Pages Standard Tag Library (hereafter called the
"JSTL"), along with the expression language (sometimes called the "EL") used
for evaluating attribute values.

Tag Mapping
-----------

In implementing the Struts-EL library, every Struts tag that provides a feature
that is not covered by the JSTL (1.0) library is mapped into the Struts-EL
library.  This section reviews which Struts tags are NOT implemented in the
Struts-EL library, and which JSTL tags provide that feature.

Many of the non-porting decisions were based on the fact that the JSTL
expression language itself provides the same functionality.  In those cases, in
addition to a possible JSTL tag name, the symbol "EL" will be listed.

Bean Tag Library Tags NOT Implemented in Struts-EL
--------------------------------------------------

Struts Tag        JSTL Tag
----------        --------
cookie                          c:set, EL
define           c:set, EL
header                          c:set, EL
include          c:import
parameter         c:set, EL
write             c:out

Logic Tag Library Tags NOT Implemented in Struts-EL
--------------------------------------------------

Struts Tag        JSTL Tag
----------        --------
empty                                   c:if, c:when, EL
equal                                   c:if, c:when, EL
greaterEqual            c:if, c:when, EL
greaterThan                     c:if, c:when, EL
lessEqual                       c:if, c:when, EL
lessThan                                c:if, c:when, EL
notEmpty                                c:if, c:when, EL
notEqual                                c:if, c:when, EL
notPresent                      c:if, c:when, EL
present                         c:if, c:when, EL

Html Tag Library Tags NOT Implemented in Struts-EL
--------------------------------------------------

None (all of them were ported).

Attribute Mapping
-----------------

At this point of the implementation, there is only one change (to two similar
tags) to the set of attributes between the Struts tags, and the Struts-EL tags.
The "logic:match" and "logic:notMatch" tags have an additional attribute named
"expr", which can take any value, and will be used as the value to compare
against, in addition to the choices of "cookie", "header", "name"/"property",
and "parameter".

Usage Requirements
------------------

The Struts-EL tag library requires the use of the Struts tag library, and the
Java Server Pages Standard Tag Library.  It is not necessary for JSP pages
using the Struts-EL tag library to also use the Struts tags or the JSTL tags,
but the Struts and JSTL tag libraries need to be part of the application
utilizing the Struts-EL tag library.

This is because the Struts-EL tag classes are all subclasses of Struts tag
classes, and their implementation uses classes provided by the JSTL.

--
To unsubscribe, e-mail:   <mailto:[EMAIL PROTECTED]>
For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>

Reply via email to