Django - cannot assign - must be an instance - django

Question

I tried phrasing this question recently and got totally confused. I've extended the default user model with this in my models.py:
class Biography(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
biography = models.TextField(max_length=500, blank=True,default='Details')
I've included this in the forms.py:
class EditProfileForm(forms.Form):
first_name = forms.CharField(label='First Name')
last_name = forms.CharField(label='Last Name')
biography = forms.CharField(label='Biography', widget=Textarea(attrs={'rows': 5}))
I have a view to edit the profile and want to add "biography" to it, but have absolutely no clue where to start. Here's the view:
def edit_profile(request):
user = request.user
products = Product.objects.filter(user=user)
form = EditProfileForm(request.POST or None, initial={'first_name':user.first_name, 'last_name':user.last_name})
if request.method == 'POST':
if form.is_valid():
user.first_name = request.POST['first_name']
user.last_name = request.POST['last_name']
user.save()
return render(request, 'profile.html', {'user':user, 'products':products})
context = {"form": form}
return render(request, "edit_profile.html", context)
I tried to replicate what is already there with this:
def edit_profile(request):
user = request.user
products = Product.objects.filter(user=user)
biography = Biography(user=user)
form = EditProfileForm(request.POST or None, initial={'first_name':user.first_name, 'last_name':user.last_name, 'biography':user.biography})
if request.method == 'POST':
if form.is_valid():
user.first_name = request.POST['first_name']
user.last_name = request.POST['last_name']
user.biography = request.POST['biography']
user.save()
return render(request, 'profile.html', {'user':user, 'products':products})
context = {"form": form}
return render(request, "edit_profile.html", context)
I definitely missed the point somehow. The last time I asked this question I was somewhat chastised for not knowing how to solve it. In all honesty I'm really new to Django and am amazed I got this far, but I'm stuck. I 'think' I need to create an instance but am not sure how.

Answer 1

What you should do differently:
Create Biography instance if it does not exist, or get from db.
Instantiate separate forms for different request methods
Use cleaned_data as input validation is one of the main purposes of forms
Always redirect after POST
Save User and Biography instances separately
And you don't need related products in form view. If only you are not going to somehow update them here.
For example:
def edit_profile(request):
user = request.user
biography, created = Biography.objects.get_or_create(user=user)
form = EditProfileForm(initial={
'first_name': user.first_name,
'last_name': user.last_name,
'biography': biography.biography
})
if request.method == 'POST':
form = EditProfileForm(data=request.POST)
if form.is_valid():
user.first_name = form.cleaned_data['first_name'] # use cleaned_data
user.last_name = form.cleaned_data['last_name']
biography.biography = form.cleaned_data['biography']
biography.save() # save Biography object
user.save() # save User object
return redirect(biography) # always redirect after successful POST. In this case Biography must have get_absolute_url() method
context = {'form': form}
return render(request, 'edit_profile.html', context)
Read more in documentation.

Answer 2

user.biography is an instance of Biography model, so what you should do here is get that instance and edit its attributes, like this:
bio = user.biography
bio.biography = request.POST['biography']
bio.save()