ColdMVC: Binding

I really like the binding option in the form tag of ColdMVC. It takes an object from the param scope, prefixes all the elements within it, with model's name (ex. user.first_name), and sets the value from the object. It's very handy. Here is an example of what it currently does:

<c:form controller="user" action="save" bind="user">
 <c:hidden name="id"/>
 
 <c:input name="first_name"/>
 <c:input name="last_name"/>
 
 <c:buttons>
  <c:submit label="save"/>
 </c:buttons>

</c:form>

If you wanted to bind the form to 2 or more objects it would be cool if you could use a bind tag and group a set of elements within a form.

<c:form controller="student" action="save">

 <c:bind key="user">
  <c:hidden name="id"/>
  
  <c:input name="first_name"/>
  <c:input name="last_name"/>
 </c:bind>
 
 <c:bind key="student">
  
  <c:input name="student_number"/>
 
 </c:bind>
 
 <c:buttons>
  <c:submit label="save"/>
 </c:buttons>

</c:form>

Or even better on the tag itself. (I think this available already, but I am not sure).

<c:form controller="student" action="save">

 <c:hidden name="id" bind="user"/>
 
 <c:input name="first_name" bind="user"/>
 <c:input name="last_name" bind="user"/>
 <c:input name="student_number" bind="student"/>

 <c:buttons>
  <c:submit label="save"/>
 </c:buttons>

</c:form>