Django 1.6 - reusable view with redirect - django

Question

I have just made reusable comments app that can be attached to any model, please see view I have problem with ( I didn't include whole logic, only the one relevant to the question).
When there is no request.POST, all is working fine, however when I try to add the comment, after it is saved there is some problem with redirect, I am getting error
dictionary update sequence element #0 has length 0; 2 is required
problematic line is context.update(dictionary). It looks like it is empty when comment is added, but I don't understand why.
My logic is this:
when there is no request.POST, view add_comment will return
{'comment_form': comment_form, 'comments': comments}
when request.method==POST' , context.update(dictionary) shouldn't
be even executed, because of return redirect(node). It should result
in starting code executing in view profile, because that's where
redirect(node) should lead to.
I know I could just use redirect in profile.views.py, but then I will need to do this for every view with added comments, which is extremely unconvenient.
comment.views.py
from django.shortcuts import redirect
from comment.forms import AddCommentForm
from comment.models import Comment
def add_comment(request, node):
if request.user.is_authenticated():
user = request.user
else:
user = None
comment_form = None
comments = Comment.objects.get_comments(node) # custom manager method for getting all comments
if user:
if request.method == 'POST':
comment_form = AddCommentForm(request.POST)
if comment_form.is_valid():
comment_form.save(node=node, user=user) # custom form save method, updating missing fields
return redirect(node) #redirect to node.get_absolute_url()
else:
comment_form = AddCommentForm()
return {'comment_form': comment_form, 'comments': comments}
profile.views.py - another app, I want to reduce the code for adding comment by only referring to view add_comment
from django.shortcuts import render, get_object_or_404
from django.contrib.auth.models import User
from comment.views import add_comment
def profile(request, id):
user = get_object_or_404(User, id=id)
dictionary = add_comment(request, user)
context = {'user': user}
context.update(dictionary) #problematic line
return render(request, 'profile/profile account.html', context)

Answer 1

The problem is that add_comment can return something that isn't a dictionary: that is, a redirect (which is a subclass of HttpResponse). You could always check the type of what is returned before using it:
result = add_comment(request, user)
if not isinstance(result, dict):
return result
else:
context.update(result)