Link function only gets called once, so it would not directly do what you are expecting. You need to use angular $watch to watch a model variable.

This watch needs to be setup in the link function.

If you use isolated scope for directive then the scope would be

scope :{typeId:'@' }

In your link function then you add a watch like

link: function(scope, element, attrs) {

    scope.$watch(typeId,function(newValue,oldValue) {

        //This gets called when data changes.

    });

 }

If you are not using isolated scope use watch on some_prop