pythondjangodjango-modelspermissions

How to retrieve all permissions of a specific model in django?


By default each django model has 3 permissions (add, change, delete). In a model I can define my custom permission to adds more.

class Company(models.Model):
    owner = models.ForeignKey(User)
    name = models.CharField(max_length=64, unique=True)
    description = models.TextField(max_length=512)
    created_on = models.DateTimeField(auto_now_add=timezone.now)

    class Meta:
        permissions = (
            ("erp_view_company", "Can see the company information"),
            ("erp_edit_company", "Can edit the company information"),
            ("erp_delete_company", "Can delete the company"),
        )

When you migrate, these permissions are automatically created at DB level. How can you retrieve all the permissions from a model?

# retrieves the permissions
permissions = Permission.objects.filter(get_all_permissions_of_model_Company)
# adds permissions to group
group = Group.objects.create(name='foo', permissions=permissions)
# adds user to group
user.groups.add(group)

Solution

  • I would suggest you something like this:

    all_permissions = Permission.objects.filter(content_type__app_label='app label', content_type__model='lower case model name')
    

    Retrieving model's app_label:

    Company._meta.app_label
    

    Retrieving model's lower case name:

    Company._meta.model_name
    

    Also, you can retrieve a ContentType instance representing a model:

    ContentType.objects.get_for_model(Company)
    

    Since ContentType uses a cache, it is quite acceptable. Thus, there is another way to achieve what you need:

    content_type = ContentType.objects.get_for_model(Company)
    all_permissions = Permission.objects.filter(content_type=content_type)