Django: Access request object from admin's form.clean()

Question

My question is very similar to this one: How do I access the request object or any other variable in a form's clean() method?

Except, I have the same problem with admin form. So I can't see a way to init the form myself, therefore - to pass a request to it.

Thanks beforehand.

Answer 1

Indeed, there is a way to solve your issue!

You will need to subclass form provided by ModelAdmin.get_form() and override it:

class BusinessDocumentCommentForm(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        self.request = kwargs.pop('request', None)
        # Voila, now you can access request anywhere in your form methods by using self.request!
        super(BusinessDocumentCommentForm, self).__init__(*args, **kwargs)
        if self.request.GET.get('document_pk', False):
            #Do something
    def clean(self):
        # Do something with self.request
        # etc.    
    class Meta:
        model = BusinessDocumentComment

class BusinessDocumentCommentAdmin(admin.ModelAdmin):

    form = BusinessDocumentCommentForm     

    def get_form(self, request, obj=None, **kwargs):

        AdminForm = super(BusinessDocumentCommentAdmin, self).get_form(request, obj, **kwargs)

        class AdminFormWithRequest(AdminForm):
            def __new__(cls, *args, **kwargs):
                kwargs['request'] = request
                return AdminForm(*args, **kwargs)

        return AdminFormWithRequest

Answer 2

There are a number of hooks in the ModelAdmin class to allow you to do things this - look at the code in django.contrib.admin.options.

Two methods that might help you are ModelAdmin.save_form and ModelAdmin.save_model, both of which are passed the request object. So you can override these methods in your Admin subclass and do any extra processing you need.

Edited after comment

You're quite right that this won't let you validate the form dependent on the user's privileges. Unfortunately the form instantiation is buried deep within the add_view and change_view methods of ModelAdmin.

There aren't many possibilities without duplicating a lot of existing code. You could override the *_view methods; or you could try and override the modelform_factory function to return a new class with the request object baked in already; or you could try fiddling with the form class __new__ method to do the same thing, but that's tricky because of the form metaclass.