On Wed, 14 Aug 2002, R.C.Nougain wrote:
> Date: Wed, 14 Aug 2002 11:02:04 +0530
> From: R.C.Nougain <[EMAIL PROTECTED]>
> Reply-To: Tomcat Users List <[EMAIL PROTECTED]>
> To: Tomcat Users List <[EMAIL PROTECTED]>
> Subject: Re: jsp in packages
>
> Craig,
>
> Your response confirms what I thought. My questions was purely educational
> and not that I am having such cases in my code. Thanks for your response.
> Surely no one should put logic in the PL (jsp). But someone could define and
> use a utility method (eg putting a HTML table showing some data eg date etc)
> in jsp. I positive that this is something that could be done if not in
> current JSP version but in future versions. There could be a directive eg
> THIS.doit() that gets translated by the JSP engine into something like
> colrs$jsp.doit() (colrs.jsp is the jsp file). Though it is certainly not
> that important as required but could be done. Perhaps also at instance
> level!
>
In general, that is what JSP custom tags are for. Among other things,
they let you create arbitrary dynamic output, based on the parameters you
specify for that tag. Good examples to look at include:
* The JSP standard tag library (available via Apache as the 'standard"
tag library at <http://jakarta.apache.org/taglibs>.
* Tags that generate arbitrarily complex HTML output, such as the tags
provided by the Struts framework <http://jakarta.apache.org.struts/>.
However, in none of these cases do you see any processing functions being
stored in a JSP page and called from another - that would not conform to
good object oriented design principles. Instead, you see the common
paradigm of using request attributes to share information within the time
frame of a given request, or session attributes to share information
across multiple requests for a given user.
Writing functions in a JSP page (wrapped in <%! ... %> delimiters) is evil
... don't even bother learning how to do it.
> Thanks
>
Craig
>
> ----- Original Message -----
> From: "Craig R. McClanahan" <[EMAIL PROTECTED]>
> To: "Tomcat Users List" <[EMAIL PROTECTED]>
> Sent: Tuesday, August 13, 2002 9:18 PM
> Subject: Re: jsp in packages
>
>
> >
> >
> > On Tue, 13 Aug 2002, D Bamud wrote:
> >
> > > Date: Tue, 13 Aug 2002 12:27:53 +0530
> > > From: D Bamud <[EMAIL PROTECTED]>
> > > Reply-To: Tomcat Users List <[EMAIL PROTECTED]>
> > > To: Tomcat Users List <[EMAIL PROTECTED]>
> > > Subject: jsp in packages
> > >
> > > Q1. Can I declare my jsp files in packages? How?
> > >
> >
> > No. You have zero control over what package the JSP compiler puts your
> > page in, or even what the class name of the generated servlet is.
> >
> > > Q2. I have written a static method in one jsp page. I want to call this
> > > method in another jsp page. How to do it? I do not want to take this
> method
> > > out from the jsp and put into a class (.java) and use it in both the jsp
> > > files.
> > >
> >
> > You need to rethink your "do not want to take this method out"
> > statement. JSP pages and servlets are designed to be totally independent
> > components, and you can't get a reference to an instance of one page or
> > servlet from another. Shared logic and shared data *must* be stored in
> > separate classes.
> >
> > And, you're going to need to understand how to organize your code properly
> > to work on larger scale projects anyway, so now is a good time to start.
> > Hint -- putting logic in your JSP pages is not a good design practice.
> >
> > Craig
> >
> >
> > --
> > 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]>
>
>
--
To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]>
For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
