How to modify data before validation for m2m?

Question

linux

Django.
Surely this is googled, but I find it difficult to correctly formulate the question. For simplicity, I'll sketch out the code:

class A(models.model):
   name = models.CharField()

class B(models.Model):
   name = models.CharField
   categories = models.ManyToMany(A)

class BForm(ModelForm):
    class Meta:
        model=B

class MyView(CreateView):
    form = BForm
    model = B

More or less like this. The form is sent by ajax. The problem is that the categories value is generated by a js snippet and sent to the server as an array of model A ids. The form validation generally swears that the categories field is not filled in - indeed, it is not in clenead_data, but it is in data. How to keep in shape?

Answer 1

To save the form, you can do this:
Or like this (If the previous one does not work), but this is more a crutch:

def __init__(*args, **kwargs):
    super(BForm, self).__init__(*args, **kwargs)
    self.fields['category'].required = False

Ps: I see that django expects something like this:

------WebKitFormBoundary9Vc3EoEBGNRCydFq
Content-Disposition: form-data; name="user_permissions"

43
------WebKitFormBoundary9Vc3EoEBGNRCydFq
Content-Disposition: form-data; name="user_permissions"

41
------WebKitFormBoundary9Vc3EoEBGNRCydFq
Content-Disposition: form-data; name="user_permissions"

49
------WebKitFormBoundary9Vc3EoEBGNRCydFq
Content-Disposition: form-data; name="user_permissions"

42
------WebKitFormBoundary9Vc3EoEBGNRCydFq
Content-Disposition: form-data; name="user_permissions"

40
------WebKitFormBoundary9Vc3EoEBGNRCydFq
Content-Disposition: form-data; name="user_permissions"

30

Pps: These are things from php, django can't do that:

a[]=1
a[]=2