CODEWITHSUNDEEP
javajsptomcat
Black
Black

Reputation: 5367

How to write a JSP which renders a list of JSP fragments, without IF switching code

I have a JSP which composes a List of Objects, then renders JSP fragments depending on the Class of each of the objects in the List. At the moment, this is done with a huge chain of if statements inside the 'parent' JSP:

   if( bean.getFilterChildByType( Level.class ) != null )
   {
   %> <jsp:include page="filters/level.jsp"/> <% 
   }
   if( bean.getFilterChildByType( Sources.class ) != null )
   {
   %> <jsp:include page="filters/sources.jsp"/> <% 
   }
   ...

So, my question is, in JSP (Tomcat) is it possible to achieve this same functionality without an if chain, just by iterating the Objects in the list and perhaps taking advantage of the naming convention "Class name".jsp ? I've played with:

<%@ include file="filename" %>

but this doesn't seem to allow variables in the file-name either.

Upvotes: 2

Views: 502

Answers (3)

Pintobean77
Pintobean77

Reputation: 1415

This is a tough one!

If the included jsp files (level.jsp, source.jsp, etc) are not too complex, what about shifting the HTML from those files over to a function call of the objects you are calling bean.getFilterChildByType(...) on?

That way, instead of a large if/else tree, you could then just call:

String html = bean.getHtmlForType();

...would likely work out much cleaner in a loop too.

Upvotes: 0

Nrj
Nrj

Reputation: 6831

Resolve the appropriate jsp to be included (based on bean.getFilterChildByType) at the controller side and then just pass the name of the jsp to the container jsp. Now this can be easily included.

Upvotes: 0

Basanth Roy
Basanth Roy

Reputation: 6490

Something like this should work

<jsp:include page="filters/<%=filename%>.jsp"/>

Upvotes: 2

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