[Solved]-Extending Django's Generic Views

You can do this by overriding the get_form method:

from django.views.generic import CreateView

class CustomCreateView(CreateView):
    def get_form(self, form_class):
        form = super(CustomCreateView, self).get_form(form_class)
        form.instance.user = self.request.user
        return form

EDIT: Nowadays I would override form_valid as per Issac Kelly’s answer:

from django.views.generic import CreateView

class CustomCreateView(CreateView):
    def form_valid(self, form):
        form.instance.user = self.request.user
        return super(CustomCreateView, self).form_valid(form)

You want to override the form_valid method.