Besides using the ExpressionEvaluatorManager from Jakarta (or some variation of the EvalHelper class I wrote for Struts-EL), you should consider how long you expect this tag library to be around, and if you expect people to eventually move it to a JSP 2.0 container.
If this library will have a relatively short life, and will be nonessential by the time a JSP 2.0 container comes around, then I would probably reference EEM directly in the tag classes of your base library. However, if you expect this library to eventually be used in a JSP 2.0 container, then having the EEM calls in your tag library will be a liability (sort of a noop). In that case, you might consider having your base library not know anything about expression evaluation, and then have a "lib-el" library, where all the tags are subclasses of the tags in the base library, and all they do is pass attribute values through the EEM, and call the setter methods in the base class. The advantage of this approach is that when you move to a JSP 2.0 container, you just throw away the "lib-el" library and use your base library. You also gain the ability to continue to put "business logic" in your base library, and have the "lib-el" library just deal with expression evaluation. This is exactly how the Struts-EL library is structured. -----Original Message----- From: Chan, Jim [mailto:[EMAIL PROTECTED] Sent: Friday, March 26, 2004 4:08 PM To: '[EMAIL PROTECTED]' Subject: Use JSP Expression Language in custom tags? Sorry this is not directly related to Struts, but is it possible to use the expression language in custom tags? I think you can, but I am not quite sure how to do it. Do you get this for free by just upgrading to a JSP 2.0 compliant server? Or do I have to do something with the custom tags to get this behaviour. For example, I want to do my tag to get his behaviour: <car:model description="<%= ((Car)request.getAttribute("Honda")).getDescription() %>" /> using the EL like this. <car:model description="${ Honda.description }" /> --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
