Django: Passing variable from get_context_data() to post()

Question

The variable is defined inside get_context_view() since it requires an id to access correct database object:

class FooView(TemplateView):
  def get_context_data(self, id, **kwargs):
    ---
    bar = Bar.objects.get(id=id)
    ---

  def post(self, request, id, *args, **kwargs):
    # how to access bar?
    # should one call Bar.objects.get(id=id) again?

What would be the way to pass bar variable to post()?

Tried to save it as FooView's field and access it via self.bar, but this doesn't do the trick. self.bar is not seen by post()

Answer 1

You should reverse it. If you need bar in post(), you need to create it there:

class FooView(TemplateView):
    def get_context_data(self, **kwargs):
        bar = self.bar

    def post(self, request, id, *args, **kwargs):
        self.bar = Bar.objects.get(id=id)
        ...

post() is called before get_context_data, that's why post doesn't see it if you define it in get_context_data.

Answer 2

I know its late, but I faced this same problem few days ago. However here is my solution.

def get_context_data(self, **kwargs):
    context = super().get_context_data(**kwargs)
    context['foos'] = self.object.filter()
    return context

def post(self, request, *args, **kwargs):
    context = super().post(request, *args, **kwargs)
    foos = self.get_context_data().get('foos')
    # do stuff here
    return context

Answer 3

As knbk said, my solution was the dispatch method, there I define the variables that I will use in get_context_data and in post methods, that worked for me as a way to share data here my example

def dispatch(self, request, *args, **kwargs):

    self.some_data = '123'
    if request.method.lower() in self.http_method_names:
        handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
    else:
        handler = self.http_method_not_allowed
    return handler(request, *args, **kwargs)

def get_context_data(self, **kwargs):
    context = super(MyTestCreateView, self).get_context_data(**kwargs)
    print('test get_context_data', self.some_data)

def post(self, request, *args, **kwargs):        
    print('test post', self.some_data)
    return super().post(request, *args, **kwargs)

Classy CBV I hope it helps

Answer 4

If the variable is defined in your CBV (Class Based View), it can directly be called in your template.

Views.py

class SomeRandomView(FormView):
    username = 'SomeValue'

Template.html

<p>Username is {{view.username}}<p>

Sidenote: You can even call the methods in your view class directly within the template file which is after version 1.5 Django if I could recall correctly.