form doesn't allow editing

Question

I have a following form:

class PlayForwardPageForm(forms.ModelForm):        
    def __init__(self, *args, **kwargs):
        super(PlayForwardPageForm, self).__init__(*args, **kwargs)

    class Meta:
        model = PlayForwardPage
        exclude = ( 'id',)

    def save(self, *args, **kwargs):     
        post = super(PlayForwardPageForm, self).save(*args, **kwargs)
        post.save()

and view that shows it :

object = PlayForwardPage.objects.all()[0]
form = PlayForwardPageForm(instance=object)

if request.method == "POST":
    form = PlayForwardPage(data=request.POST, instance=object)
    if form.is_valid():
        form.save()
        return HttpResponseRedirect(reverse('manage_playforward',))
else:
    form = PlayForwardPageForm(instance=object)

When loading page everything works fine. But when I try to save the form with changed data I get:

'data' is an invalid keyword argument for this function

Can anyone see any reason or this behavior ?

Answer 1

Short answer: PlayForwardPage is a model not a ModelForm.

Here's the corrected code, with some extra style comments.

# Don't shadow built-ins (in your case "object")
play_forward_page = PlayForwardPage.objects.all()[0]
# Don't need this form declaration.  It'll always be declared below. form = PlayForwardPageForm(instance=object)

if request.method == "POST":
    # Should be a the form, not the model.
    form = PlayForwardPageForm(data=request.POST, instance=play_forward_page)
    if form.is_valid():
        form.save()
        return HttpResponseRedirect(reverse('manage_playforward',))
else:
    form = PlayForwardPageForm(instance=play_forward_page)

Also, you're doing some unnecessary things in your PlayForwardPageForm:

class PlayForwardPageForm(forms.ModelForm):        

# This __init__ method doesn't do anything, so it's not needed.
#    def __init__(self, *args, **kwargs):
#        super(PlayForwardPageForm, self).__init__(*args, **kwargs)

    class Meta:
        model = PlayForwardPage
        exclude = ( 'id',)

#  You don't need this since you're not doing anything special.  And in this case, saving the post twice.
#    def save(self, *args, **kwargs):     
#        post = super(PlayForwardPageForm, self).save(*args, **kwargs)
#        post.save()

Answer 2

You don't need to put data=request.POST. Use just request.POST