Subclassing Django class based views? - django

Question

I'm trying to warp my head around Django's new class-based views from 1.3.
I've done a bit of reading:
http://reinout.vanrees.org/weblog/2011/08/24/class-based-views-usage.html
http://www.caktusgroup.com/blog/2011/12/29/class-based-views-django-13/
But the one thing I haven't seen an example of, or how to do is, can several views subclass a common 'parent' class, reusing the data from there? (Pardon my thrashing of the common nomenclature)
An example of what I am trying to do:
class MyParentClass(TemplateView):
def get(self, request, *args, **kwargs):
session_data = request.session
other_variables = foovars
return self.render_to_response(context)
class MyChildClassOne(TemplateView):
template_name = "template_one.htm"
def get(self,request, *args, **kwargs):
resultant_data = foodata
return {'data' : resultant_data }
class MyChildClassTwo(TemplateView):
template_name = "template_two.htm"
def get(self,request, *args, **kwargs):
other_data = foootherdata
return {'data' : other_data }
So that the only difference between the two child classes is the templates they use and the 'data' they return. Both views would also return session_data and other_variables from the parent class, and therefore not repeating "return session_data, other_variables" in every child class.

Answer 1

First, don't override your view's get method. That's dangerous for several reasons I won't go into here.
Anmyway, what you need is the get_context_data method, which returns the context dict which is being passed to the template.
So, both your child views should look something like:
class ChildView(ParentView):
template_name = "foo"
def get_context_data(self, **kwargs):
context = super(ChildView, self).get_context_data(**kwargs)
context.update({
'foodata': 'bardata',
})
return context
But this is pretty much how views work out of the box; why do you think you need to subclass from an additional custom view class?

Answer 2

Here's a possible way: Your parent class will return a variable called data in the context which will be set by the child class.
Example:
class MyParentClass(TemplateView):
def get(self, request, *args, **kwargs):
session_data = request.session
other_variables = foovars
context['data'] = data
return self.render_to_response(context)
class MyChildClassOne(MyParentClass):
template_name = "template_one.htm"
def get(self,request, *args, **kwargs):
data = foodata
return super(MyChildClassOne, self).get(request, args, kwargs)
class MyChildClassTwo(MyParentClass):
template_name = "template_two.htm"
def get(self,request, *args, **kwargs):
data = foootherdata
return super(MyChildClassTwo, self).get(request, args, kwargs)
Both your child classes inherit from MyParentClass, whose get method automatically sets a variable named data into the context. The data values are provided by the child classes. Once done they call the parent's get method to perform the common operations, including rendering.