Permission control techniques in the Django framework (Part 2)

Permission control skills in the Django framework (Part 2)

In the Django framework, permission control is a very important part. In the previous article, we have introduced some basic permission control techniques in the Django framework, including using the built-in permission authentication system and decorator-based permission control. This article will continue to explore other permission control techniques in the Django framework.

1. Custom authentication backend

In the Django framework, we can use a custom authentication backend to implement customized authentication logic. By inheriting Django's authentication backend class and implementing its authentication methods, we can define our own authentication logic. For example, we can use a custom authentication backend to implement LDAP or OAuth based authentication.

The following is an example of using a custom authentication backend to implement LDAP-based authentication:

from django.contrib.auth.backends import BaseBackend
import ldap

class LDAPBackend(BaseBackend):
    def authenticate(self, request, username=None, password=None, **kwargs):
        ldap_server = "ldap://example.com"
        ldap_base_dn = "ou=people,dc=example,dc=com"
        conn = ldap.initialize(ldap_server)
        try:
            conn.simple_bind_s("uid=%s,%s" % (username, ldap_base_dn), password)
            return User.objects.get(username=username)
        except ldap.INVALID_CREDENTIALS:
            return None

In the above example, we inherit Django's BaseBackend class and implement the authenticate method in it to define your own authentication logic. In this method, we use Python's ldap module to connect to the LDAP server and verify that the username and password are correct through the simple_bind_s method. If the verification is successful, the User object is returned.

After we complete writing the custom authentication backend, we need to specify the authentication backend class in the Django settings file:

AUTHENTICATION_BACKENDS = ['path.to.LDAPBackend']

2. Use django-guardian for fine-grained permission control

django-guardian is a very powerful third-party application in the Django framework, which provides fine-grained permission control functions. Compared with Django's built-in permission authentication system, django-guardian provides a more flexible and customized permission control method.

The use of django-guardian is very simple. You only need to install and specify AUTHENTICATION_BACKENDS and AUTHORIZATION_BACKENDS in the Django settings file. For example:

# settings.py

AUTHENTICATION_BACKENDS = ('django.contrib.auth.backends.ModelBackend',)

INSTALLED_APPS = (
    # ...
    'guardian',
)

MIDDLEWARE_CLASSES = (
    # ...
    'guardian.middleware.PermissionDeniedMiddleware',
)

AUTHORIZATION_BACKENDS = (
    'guardian.backends.ObjectPermissionBackend',
)

django-guardian provides some decorators that can be used to control access to specific objects in the model. For example:

from django.views.generic import DetailView
from guardian.decorators import permission_required
from myapp.models import MyModel

@permission_required('myapp.view_mymodel', (MyModel, 'pk', 'pk'))
class MyModelDetailView(DetailView):
    model = MyModel

In the above example, we used the permission_required decorator to control the access permissions of MyModel. The decorator needs to specify the permissions and object information to be verified. If permission verification fails, a PermissionDenied exception will automatically be thrown.

3. Use django-rules for rule-based permission control

django-rules is another very practical third-party application that provides rule-based permission control functionality . Compared to django-guardian, django-rules is simpler and lightweight.

The use of django-rules is similar to the use of django-guardian. You only need to install and specify AUTHENTICATION_BACKENDS and AUTHORIZATION_BACKENDS in the Django settings file. For example:

# settings.py

INSTALLED_APPS = (
    # ...
    'rules',
)

AUTHENTICATION_BACKENDS = ('django.contrib.auth.backends.ModelBackend',)

AUTHORIZATION_BACKENDS = ('rules.permissions.ObjectPermissionBackend',)

Using django-rules for permission control requires defining a set of rules, each of which contains a condition and a result. If the conditions are met, the operation in the result will be performed, otherwise it will not be performed. For example:

from rules import rule
from myapp.models import MyModel

@rule('view', 'myapp.view_mymodel')
def can_view_mymodel(user, mymodel):
    return True

@rule('change', 'myapp.change_mymodel')
def can_change_mymodel(user, mymodel):
    return user.is_superuser or user == mymodel.user

In the above example, we defined two rules to control the permissions to view and modify the MyModel object. In each rule, we use the rule decorator to define conditions and results. Two parameters, user and mymodel, need to be passed in the condition for permission judgment. If the permission is passed, you can continue to perform subsequent operations.

After writing the rules, we need to add the rules to Django:

# settings.py

RULES_MODULE = 'myapp.rules'

In the above example, we use RULES_MODULE to specify the Python module where the rules are located. In this way, Django can automatically load the rules when it starts.

Summary

In the Django framework, permission control is a very important and essential function. Through some of the techniques introduced above, we can easily implement basic or complex permission control functions. Whether using the built-in authentication system, decorator-based permission control, custom authentication backend, django-guardian or django-rules, we can choose the most appropriate permission control method based on specific business needs.

The above is the detailed content of Permission control techniques in the Django framework (Part 2). For more information, please follow other related articles on the PHP Chinese website!