Django convert string into model for form

Question

I'm trying to write a simple reusable Django app which links into the User model but since this can be replaced I need to link it into AUTH_USER_MODEL.

This is fine within models but I have a formset based on the User so I need a form which I'm trying to populate as follows:

from django.forms import ModelForm
from django.forms.models import inlineformset_factory

from optin.models import UserOptin
from django.conf import settings
#from django.contrib.auth.models import User
USER_MODEL = getattr(settings, 'AUTH_USER_MODEL', None) or \
             'auth.User'

class UserForm(ModelForm):
    class Meta:
        model = USER_MODEL
        fields = '__all__'


class UserOptinForm(ModelForm):
    class Meta:
        model = UserOptin
        fields = '__all__'

UserOptinFormSet = inlineformset_factory(USER_MODEL, UserOptin,
form=UserOptinForm, extra=0)

This generates an error:

AttributeError: 'unicode' object has no attribute '_meta'

This is because USER_MODEL is a string. How do I convert it into the actual model?

Lemayzeur · Accepted Answer · 2018-05-13 14:41:50Z

2

You can use eval() function, all expressions argument parsed inside will be evaluated as a Python expression More info can be found here

USER_MODEL = eval(getattr(settings, 'AUTH_USER_MODEL', None) or 'auth.User') 
# The fallback will raise an Error here

I suggest that you import User from django.contrib.auth.models Because, if AUTH_USER_MODEL is not defined, the fallback will be auth.User, it will raise NameError no module name auth, so you may use the following

from django.contrib.auth.models import User
USER_MODEL = eval(getattr(settings, 'AUTH_USER_MODEL', None) or 'User')

answered May 13, 2018 at 14:41

Lemayzeur

8,5153 gold badges27 silver badges55 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

HenryM Over a year ago

this looks promising but gives me NameError: name 'auth' is not defined

Lemayzeur Over a year ago

which option that you choose? the seconds is the one that you shoud use, because there'is no module 'auth' imported

HenryM Over a year ago

The second is the option I chose

Lemayzeur Over a year ago

what is the value of AUTH_USER_MODEL in settings.py

Lemayzeur Over a year ago

I thing AUTH_USER_MODEL is auth.User in your settings.py that's why you have this error. when eval() tries to convert it, it actually doesn't find the auth package

Collectives™ on Stack Overflow

Django convert string into model for form

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related