form.is_valid() is returning False when using ModelForm

Question

I am creating a form using ModelForm to let the users upload a file along with a description . The is_valid() function isn't returning true and I am really confused. I have searched and there are many questions with same title as mine but they don't solve my problem.

here is forms.py:

class PostForm(forms.ModelForm):
    document = forms.FileField(widget=forms.FileInput)

class Meta:
    model = FeedModel
    fields = ['description', 'document']

Here is models.py:

class FeedModel(models.Model):
    description = models.CharField(max_length=255, blank=True)
    document = models.FileField()
    like = models.IntegerField(default=0)
    dateTime = models.DateTimeField(auto_now=True, auto_created=True)
    user = models.ForeignKey(User, on_delete=models.CASCADE, default=0)

    def get_absolute_url(self):
        u=self.user
        return reverse('home:feed',u.primary_key)

Here is views.py:

class PostView(CreateView):
    form_class = PostForm
    template_name = 'home/feedModel_form.html'

    def get(self, request, *args, **kwargs):
        form=self.form_class(None)
        return render(request, self.template_name, {'form':form })

    def post(self, request, *args, **kwargs):
        logger = logging.getLogger(__name__)
        form=self.form_class(request.POST)

        if form.is_valid():
            user=request.user
            self.object=form.save(commit=False)
            self.object.user=user
            self.object.save()
            logger.error("voila")
            redirect({'home:feed'}, user.id)


        return render(request, self.template_name, {'form':form })


def feedview(request, user_id):
    user = User.objects.get(pk=user_id)
    return render(request, 'home/feed.html', {'user': user})

Here is feedModel_form.html:

{% extends 'home/navbar.html' %}
{% block body %}

<div class="form">
    <form action="" method="post" enctype="multipart/form-data">
        {% csrf_token %}
        {% include 'home/form.html' %}
        <button type="submit" class="button button-block"  ` 
         name="reg_btn">Post</button>`
    </form>
</div>

{% endblock %}

Here is form.html:

{% for field in form %}
<div class="field-wrap">
    <label>
    {{ field.label_tag }}<span class="req">*</span>
    </label>
    <div>{{ field }}</div>
</div>
{% endfor %}

Answer 1

To see why the form isn't valid, you should check form.errors.

One error will be because you have not passed request.FILES to the form.

form=self.form_class(request.POST, request.FILES)

There may be other errors as well. If you used {{ form }} in your template, Django would include the errors automatically. Since you are rendering the fields manually, it's up to you to include the errors.

The key problem here is that you have overridden post. That means that you're missing out on lots of the code from CreateView.

In your case, it looks like you could remove the post method, and simply override form_valid instead.

def form_valid(self, form):
    self.object=form.save(commit=False)
    self.object.user=user
    self.object.save()
    # Note that you had {'home:feed'} here which was incorrect
    return redirect('home:feed', user_id)