Thanks a lot Luca. Well, it helps a lot because I was starting to feel that it's me who can not understand this thing, but now I'm relieved. As to whether it actually solves the problem, I'm not sure, as it seems that this is still not production yet, so I might have a problem selling it to my manager, but we'll see :)
Thanks again :) -----Original Message----- From: Luca Passani [mailto:[EMAIL PROTECTED] Sent: Wednesday, March 22, 2006 2:23 PM To: Tag Libraries Users List Subject: Re: Mixing EL and Java expressions Since Martin Cooper is probably still sleeping in his time zone, here is how I fixed the constants problem thanks to him once. You need something called the unstandard tag-lib by Apache: http://jakarta.apache.org/taglibs/sandbox/doc/unstandard-doc/index.html once you have that, you can do something like (SomeClassOrInterface is where your constants are defined): <un:useConstants var="ct" className="com.mycom.app.SomeClassOrInterface" /> <c:forEach var="item" items="${list}"> <c:choose> <c:when test="${item.type == ct.EMPLOYEE}"> bla bla relevant to employee </c:when> Let me know if this helps Luca Tarek Nabil wrote: >Hi everyone, > > > >I'm moving from the Struts tag libraries to JSTL and I'm having a bit of >a hard time. Things don't work as I thought they would. For example, I'm >not able to use constants defined in classes for comparison, which is >something I used to do easily with Struts tags. Here's an example; I >want to do something if the display parameter equals the constant >DISPLAY_BY_SERVICE defined in some class and do something else if it has >the value DISPLAY_BY_BU. First, I tried this > > > > <c:choose> > > <c:when test="${param.display == <%= >MainPageAction.DISPLAY_BY_SERVICE %>}"> > > By Service > > </c:when> > > <c:when test="${param.display == <%= MainPageAction.DISPLAY_BY_BU >%>}"> > > By BU > > </c:when> > > </c:choose> > > > >That didn't even compile, so I learned my first lesson: I can not use >Java expression inside EL expressions. So, I tried this > > > > <c:set var="displayParam" value="${param.display}"/> > > <c:choose> > > <c:when test="<%= >MainPageAction.DISPLAY_BY_SERVICE.equals(displayParam) %>"> > > <%= MainPageAction.DISPLAY_BY_SERVICE %> > > </c:when> > > <c:when test="<%= >MainPageAction.DISPLAY_BY_BU.equals(displayParam) %>"> > > <%= MainPageAction.DISPLAY_BY_BU %> > > </c:when> > > </c:choose> > > > >That didn't compile either, so now I know that unlike <bean:define>, ><c:set> doesn't define a scripting variable, but only a page scope >variable. So, I tried this > > > > <c:choose> > > <c:when test="${param.display} == <%= >MainPageAction.DISPLAY_BY_SERVICE %>"> > > By Service > > </c:when> > > <c:when test="${param.display} == <%= MainPageAction.DISPLAY_BY_BU >%>"> > > By BU > > </c:when> > > <c:otherwise>Otherwise</c:otherwise> > > </c:choose> > > > >Now, that compiled. But it didn't work!!! So, now I know that the value >of test should either be the String true or an expression that evaluates >to true, so mixing expressions won't work this way. > > > >Now, this is what worked, and it's not elegant at all. > > > > <c:set var="DISPLAY_BY_SERVICE" value="<%= >MainPageAction.DISPLAY_BY_SERVICE %>"/> > > <c:set var="DISPLAY_BY_BU" value="<%= MainPageAction.DISPLAY_BY_BU >%>"/> > > <c:choose> > > <c:when test="${param.display == DISPLAY_BY_SERVICE}"> > > By Service > > </c:when> > > <c:when test="${param.display == DISPLAY_BY_BU}"> > > By BU > > </c:when> > > <c:otherwise>Otherwise</c:otherwise> > > </c:choose> > > > >What if I had 5 constants, do I have to re-define the 5 constants as >vars using <c:set>? Either I'm missing something or JSTL is really not >what I thought it was. I mean, maybe I should go back to the bean and >logic libraries from Struts, they used to really do the job for me. > > > >Could someone please guide me on this issue? > > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] ********************************************DISCLAIMER******************************************** This email and any files transmitted with it are confidential and contain privileged or copyright information. If you are not the intended recipient you must not copy, distribute or use this email or the information contained in it for any purpose other than to notify us of the receipt thereof. If you have received this message in error, please notify the sender immediately, and delete this email from your system. Please note that e-mails are susceptible to change.The sender shall not be liable for the improper or incomplete transmission of the information contained in this communication,nor for any delay in its receipt or damage to your system.The sender does not guarantee that this material is free from viruses or any other defects although due care has been taken to minimise the risk. ************************************************************************************************** --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
