How to edit/add objects using the same django form?

Question

Hey, I've searched around to do this (particularly this Q: http://stackoverflow.com/questions/1854237/django-edit-form-based-on-add-form) but I just can't get it to work.

The problem I'm having is that the form always creates a new object, instead of modifying the existing one.

This is my code:

def new_task(request, task_id=None):

if task_id is not None:
    task  = Task.objects.get(pk=task_id)
else:
    task = Task()

if request.method == 'POST': # If the form has been submitted...
    form = TaskForm(request.POST, instance=task)
    if form.is_valid():
        form.save();
        return tasks(request, 'Task #%s created successfully.' % (task.id))
else:
    form  = TaskForm(instance=task)

return custom_render('user/new_task.html',
                     {'form': form},
                     request);

Any clues on what I'm missing? Thanks

Edit: added form definitions.

class TaskForm(ModelForm):

description = CharField(max_length = 1500,
    widget= forms.Textarea(attrs={'class':'task-description'}),
    required=True)

class Meta:
    model = Task

Answer 1

Ok, after a nice night of debugging i found out what the problem was. Quite stupid actually. The problem was that on submit, task_id was None.

I worked it out by doing:

1. On the form I added: <form action="{% url App.myapp.views.new_task **task_id** %}"

2. On my views I added:

   return custom_render('user/new_task.html', {'form': form, 'submit': submit, 'task_id':task.id}, request)

That was it. A newbie mistake. If someone out there knows a nicer way I'm open to suggestions.