1 files changed, 114 insertions, 0 deletions
diff --git a/rest_framework/permissions.py b/rest_framework/permissions.py
new file mode 100644
index 00000000..655b78a3
--- /dev/null
+++ b/rest_framework/permissions.py
@@ -0,0 +1,114 @@
+"""
+Provides a set of pluggable permission policies.
+"""
+
+
+SAFE_METHODS = ['GET', 'HEAD', 'OPTIONS']
+
+
+class BasePermission(object):
+    """
+    A base class from which all permission classes should inherit.
+    """
+
+    def has_permission(self, request, view, obj=None):
+        """
+        Return `True` if permission is granted, `False` otherwise.
+        """
+        raise NotImplementedError(".has_permission() must be overridden.")
+
+
+class AllowAny(BasePermission):
+    """
+    Allow any access.
+    This isn't strictly required, since you could use an empty
+    permission_classes list, but it's useful because it makes the intention
+    more explicit.
+    """
+    def has_permission(self, request, view, obj=None):
+        return True
+
+
+class IsAuthenticated(BasePermission):
+    """
+    Allows access only to authenticated users.
+    """
+
+    def has_permission(self, request, view, obj=None):
+        if request.user and request.user.is_authenticated():
+            return True
+        return False
+
+
+class IsAdminUser(BasePermission):
+    """
+    Allows access only to admin users.
+    """
+
+    def has_permission(self, request, view, obj=None):
+        if request.user and request.user.is_staff:
+            return True
+        return False
+
+
+class IsAuthenticatedOrReadOnly(BasePermission):
+    """
+    The request is authenticated as a user, or is a read-only request.
+    """
+
+    def has_permission(self, request, view, obj=None):
+        if (request.method in SAFE_METHODS or
+            request.user and
+            request.user.is_authenticated()):
+            return True
+        return False
+
+
+class DjangoModelPermissions(BasePermission):
+    """
+    The request is authenticated using `django.contrib.auth` permissions.
+    See: https://docs.djangoproject.com/en/dev/topics/auth/#permissions
+
+    It ensures that the user is authenticated, and has the appropriate
+    `add`/`change`/`delete` permissions on the model.
+
+    This permission will only be applied against view classes that
+    provide a `.model` attribute, such as the generic class-based views.
+    """
+
+    # Map methods into required permission codes.
+    # Override this if you need to also provide 'view' permissions,
+    # or if you want to provide custom permission codes.
+    perms_map = {
+        'GET': [],
+        'OPTIONS': [],
+        'HEAD': [],
+        'POST': ['%(app_label)s.add_%(model_name)s'],
+        'PUT': ['%(app_label)s.change_%(model_name)s'],
+        'PATCH': ['%(app_label)s.change_%(model_name)s'],
+        'DELETE': ['%(app_label)s.delete_%(model_name)s'],
+    }
+
+    def get_required_permissions(self, method, model_cls):
+        """
+        Given a model and an HTTP method, return the list of permission
+        codes that the user is required to have.
+        """
+        kwargs = {
+            'app_label': model_cls._meta.app_label,
+            'model_name': model_cls._meta.module_name
+        }
+        return [perm % kwargs for perm in self.perms_map[method]]
+
+    def has_permission(self, request, view, obj=None):
+        model_cls = getattr(view, 'model', None)
+        if not model_cls:
+            return True
+
+        perms = self.get_required_permissions(request.method, model_cls)
+
+        if (request.user and
+            request.user.is_authenticated() and
+            request.user.has_perms(perms, obj)):
+            return True
+        return False