如何实现同时包含TemplateView和FormView的基于Django类的视图？

Question

I'm attempting to create a django webpage that uses class-based views. This webpage needs to have the following features:

1. The web page must take arguments via HTTP GET from the URL and use those arguments to display some information back to the user
2. The web page must collect some information from the user based on a form
3. The web page must validate the information submitted to the form by the user. If any of the form data is invalid, errors must be displayed to the user on the form, so that she can correct and resubmit.

I know how to create a webpage that does number 1 by creating a class that inherits from django.views.generic.TemplateView . I know how to create a webpage that does number 2 and 3 by creating a class that inherits from django.views.generic.editFormView . But I can't figure out how to make a webpage that does all three. I tried creating a class that inherits from both TemplateView and FormView but found that I still couldn't get at the HTTP GET data. Please advise how I can make this work.

Here is my relevant urls.py entry:

url(
    r'^myPage/(?P<myArg1>\d+)-(?P<myArg2>\d+)/?$',
    myView.as_view(), 
    name='myName'
),

Here is my view class:

class myView(FormView, TemplateView):
    template_name = 'myApp/myTemplate.html'
    form_class = myForm
    success_url = reverse_lazy("successPage")


    def get_context_data(self, **kwargs):
        context = super(myView, self).get_context_data(**kwargs)

        myArg1 = int(kwargs["myArg1"])
        myArg2 = int(kwargs["myArg2"])

        # Do some validation and some other interesting stuff here based on
        # the values of myArg1 and myArg2 and put the result into self.newArg
        self.newArg = myDummyFunction(myArg1, myArg2)

        context["form"] = self.form_class


        return context


    def form_valid(self, form):

        formField1 = form.cleaned_data.get('field1')
        logger.debug("self.newArg = %s" % self.newArg) # <--- This Fails! self.newArg doesn't exist!
        return super(myView, self).form_valid(form)

Answer 1

You're overcomplicating this. FormView - like almost all generic views - already inherits from TemplateView (or rather, from ContextMixin, which includes all the functionality you are after), so there is no need to add that second class in the declaration.

The only reason your code doesn't work already is that get_context_data is not called when the form is valid - because valid forms always redirect to another view, so there is no reason to get any context data for the current one. But you shouldn't need to access that argument inside form_valid at all: you should add it to the context dictionary inside get_context_data, and then you can access it in the template just like any other context variable.