The Struts-EL supports "EL" just like JSTL. But the Struts-EL project is all the Struts custom tags you're used to, less functionality covered by tags in the JSTL. In essence, it forces developers to use the JSTL for certain functionality instead of relying on the Struts tags. This how this would have been if the JSTL was developed before the Struts custom tags. But the JSTL came after Struts, resulting in duplicate functionality between the two tag libraries. Hence, using "Struts-EL" encourages the use of "standard" custom tags (i.e. JSTL) in lieu of the Struts tags, where possible. Here's some more info from the "readme" file in the "Struts-EL" project:
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. -----Original Message----- From: ROSSEL Olivier [mailto:[EMAIL PROTECTED]] Sent: Thursday, November 21, 2002 8:19 AM To: '[EMAIL PROTECTED]' Subject: JSTL in Struts. I wish to use JSTL taglib in my project (Struts 1.1b2). I have read on the mailing-list that latest versions of Struts contain Struts-EL. I understood that this Struts-EL is an implementation of JSTL. But it requires the nightly builds. It seems that Sun and Jakarta Taglibs also provide JSTL. To me, I could download one of them, install it manually into Struts 1.1b2 and go. My question: what's the difference between Struts-EL and Jakarta Taglib JSTL, for example? why should I use Struts-EL, instead of JSTL from other sources? ---cut here--- This e-mail is intended only for the above addressee. It may contain privileged information. If you are not the addressee you must not copy, distribute, disclose or use any of the information in it. If you have received it in error please delete it and immediately notify the sender. Security Notice: all e-mail, sent to or from this address, may be accessed by someone other than the recipient, for system management and security reasons. This access is controlled under Regulation of Investigatory Powers Act 2000, Lawful Business Practises. -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
