Django - Saving object worked one time but now it doesnt - django

Question

i want to save an object to db and it worked one time but now it doesnt, i suspect that is something to do with the Glossary
Everything
views.py
#login_required
def product_form_view(request):
if request.method == 'POST':
form = Product_Form(request.POST, request.FILES)
if form.is_valid():
product_form = form.save()
product_form.save()
return redirect('product_management_view')
else:
form = Product_Form()
return render(request, 'product-form.html', {'form': form})
models.py
class Product (models.Model):
sub_chapter = models.ForeignKey(Sub_Chapter, on_delete=models.CASCADE)
supplier = models.ForeignKey(Supplier, on_delete=models.CASCADE)
glossary = models.ManyToManyField(Glossary, blank=True )
name = models.CharField(max_length=40, blank=False, null=False)
description = models.TextField(null=True)
product_image = models.ImageField(
upload_to='media/images/product_images', blank=False, null=False)
reference = models.CharField(max_length=40, blank=False, null=False)
width = models.PositiveIntegerField()
height = models.PositiveIntegerField()
length = models.PositiveIntegerField()
unit_price = models.DecimalField(
max_digits=15, decimal_places=4, null=True)
polution = models.DecimalField(decimal_places=8, max_digits=15, null=True, blank=True )
technical_implementation = models.TextField(null=True)
def __str__(self):
return self.name
def get_absolute_url(self):
return reverse_lazy("manufacter_product_view", kwargs={'id': self.pk})
forms.py
class Product_Form(forms.ModelForm):
sub_chapter = forms.ModelChoiceField(queryset=Sub_Chapter.objects.all(),
required=True, widget=forms.Select())
supplier = forms.ModelChoiceField(queryset=Supplier.objects.all(),
required=True, widget=forms.Select())
glossary = forms.ModelChoiceField(queryset=Glossary.objects.all(),
required=False, widget=forms.SelectMultiple())
product_image = forms.ImageField(
required=True, widget=forms.FileInput())
class Meta():
model = Product
fields =[ 'name', 'description', 'reference', 'width', 'height', 'length', 'polution', 'unit_price', 'technical_implementation', 'sub_chapter', 'supplier', 'glossary', 'product_image', ]

Answer 1

There is a bug in your product_form_view, you are calling the save method on product_form variable i.e product_form.save() but product_form will have None in it as form.save() will return None on successfully saving the object,so it will break the code there.And you don't need to again call the save method at all.Calling form.save() is enough for saving the object and you should move the code in else part out of it as it not currently handling the form invalid case.
Your code should be like this:
#login_required
def product_form_view(request):
if request.method == 'POST':
form = Product_Form(request.POST, request.FILES)
if form.is_valid():
form.save()
return redirect('product_management_view')
form = Product_Form()
return render(request, 'product-form.html', {'form': form})