Spring MVC，FreeMarker和自定义TagLib

Question

In a Spring MVC with FreeMarker environment, I have a custom TagLib that process a ftl template with data and write the result in the tag's JSP context.

When I call this tag from a resolved view (meaning from a template rendered by a controller) the behaviour is totally correct.

controller
    -> FTL
        -> TagLib

But when I call it from within a template to be processed by another instance of the same tag, I got an error (the tag is not defined) and when I add the #assign statement in my FTL, I also got an error (JspTagLibs is null).

controller
    -> FTL
        -> TagLib
            -> FTL
                -> TagLib (crash!)

How could I solve this?

Thanks in advance

Answer 1

To call JSP tags from FTL, you need a special template context (data-model, in FTL terminology) that implements that. I assume Spring gives a such context for the initial call. But if you start with a new template context (with a fresh freemarker.core.Environment actually) in the second case then you won't have the support. If you don't really need a fresh template context there, you could get the Environment higher up with static Environment.getCurrentEnvironment() , and then use Environment. include Environment. include to call the 2nd FTL. However, then you will use the same set of template-created variables there as in the top-most FTL. (That can be improved somewhat if the 2nd FTL just defines a macro and calls it, because the macro can at least have locals.) So, you could just try reusing the dataModel from the higher Environment (using Environment.getDataModel() ) when you call the second FTL. I guess it should work... never tried it.