Question

I’m trying to add values to HashMap in my Freemarker template. I’m also using BeanWrapper so that I can see exposed methods from my Java objects.

In my data model, I have a HashMap:

root.put("myName", new HashMap());

As I mentioned above, Im using BeanWrapper so that I can use all the methods of my Java objects:

BeansWrapper wrapper = new BeansWrapper();
wrapper.setExposureLevel(0);
cfg.setObjectWrapper(wrapper);//cfg = new Configuration();

Now in my template file (test.ftl) I’m trying to invoke put method of HashMap (that I’ve stored in data model..above):

${myName.put["fname:John"]}

This last line does not work, and I’m getting an error:

freemarker.template.TemplateException: Expected hash. myName.put evaluated instead to freemarker.ext.beans.SimpleMethodModel on line 16, column 11 in test.ftl.

Could you tell me, how I can invoke put method of my HashMap in template file?

Answer 1

I suggest you read about Object Wrappers.

I also like this question from the FAQ, from which I will now quote,

“Maybe you should push some
calculations back to the data-model
building phase. Ideally the data-model
contains what should be displayed, and
not something that serves as the base
of further calculations.” – http://freemarker.sourceforge.net/docs/app_faq.html#faq_question_14

If you need the variable in the data model, don’t bother putting it in a map, use the assign directive.

Alas, I understand that the world is not perfect, and sometimes we must do what we can.

If you must, I suggest building an object to wrap your Map, i.e

class MapWrapper
{
        Map map = new HashMap;
        ...
       public void put(Object arg)
       {
            map.put(arg);
       }
}

Then simply put your map wrapper into your model, and you should be able to call put like any other method.