[patch] Need ability to pass a RequestContext instance to FormPreview.

[Vadim Macagon <vadim@…>]

I tried using the FormPreview class in django.contrib.formtools.preview today. But my templates rely on a RequestContext as opposed to just the plain Context produced by all the render_to_response() calls used by FormPreview.

Here's what I'm currently doing:

# urls.py

(r'^apples/add/$', 'apples.views.add_apple')


# views.py

class ApplePreview(FormPreview):
    preview_template = 'apples/preview.html'
    form_template = 'apples/form.html'
    
    def done(self, request, clean_data):
        # create apple object and save to db
        # ...
        return HttpResponseRedirect('/')

@login_required
@transaction.commit_on_success
def add_apple(request):
    # ARGH! Can't pass in a RequestContext!
    return ApplePreview(AppleForm)(request)

So I suggest modifying FormPreview slightly so that the initialization method takes an optional context_instance arg that can be passed to all the render_to_response calls in preview_get(), preview_post() and post_post(). I've attached a diff with the suggested changes. With these changes I can write this:

@login_required
@transaction.commit_on_success
def add_apple(request):
    # Yay!
    return ApplePreview(AppleForm, RequestContext(request))(request)

[Adrian Holovaty]

If we allow for a context_instance argument, as this patch provides, then it becomes necessary to wrap the FormPreview class within a view. It's intended to be used directly *as* a view rather than being wrapped.

A better way of adding the functionality, then, would just be to use RequestContext by default.

[Adrian Holovaty]

(In [4259]) Fixed #3204 -- Changed FormPreview to use RequestContext