Question

I currently have three classes User, UserProfile, and Vendor. User is the built-in Django one from from django.contrib.auth.models import User. The other two are as follow

Here is UserProfile

class UserProfile( models.Model ) :
    TYPE_CHOICES = (
        ( 't', 'tenant'           ),
        ( 'm', 'property manager' ),
        ( 'o', 'property owner'   ),
        ( 'v', 'vendor'           ),
        ( 'w', 'web user'         ),
        ( 'x', 'other'            ),
    )
    user      = models.ForeignKey( User, unique = True )
    user_type = models.CharField( max_length = 1, choices = TYPE_CHOICES, default = 't' )

User.profile = property( lambda u : UserProfile.objects.get_or_create( user = u )[ 0 ] )

And here is Vendor

class Vendor( models.Model ) :
    def __unicode__( self ) :
        return self.name

    name  = models.CharField( max_length = 135 )
    users = models.ManyToManyField( User, null = True, blank = True )

I want to limit the Vendor.users to only User whose UserProfile.user_type is vendor.

How do I use limit_choices_to. Can I do something like…

users = models.ManyToManyField( User, null = True, blank = True, limit_choices_to = { UserProfile.objects.filter( user = self.users ).user_type : 'm' } )

I know the above code will throw an error, but hopefully you can see what I’m trying to do.

Thanks in advance!

Answer 1

I was able to do it with

manager = models.ForeignKey( User, related_name = 'manager', limit_choices_to = { 'userprofile__user_type' : 2 } )

where 2 is the primary key (user_type_id) of property manager in the UserType class.