fix #79 add decorator has_perms for nodes

docs/authorization.rst

@@ -108,3 +108,28 @@ method to your ``DjangoObjectType``.
             if post.published or context.user == post.owner:
                 return post
             return None
+
+
+Permission node access
+----------------------
+
+For restrict access using permissions, use the `has_perm` decorator in node.
+
+.. code:: python
+
+    from graphene_django.types import DjangoObjectType
+    from graphene_django.decorator import has_perms
+    from .models import Post
+
+    class PostNode(DjangoObjectType):
+        class Meta:
+            model = Post
+            only_fields = ('title', 'content')
+            interfaces = (relay.Node, )
+
+        @has_perms(["django_app.django_can_see_content_permission"])
+        def resolve_content(self, id, context, info):
+            return self.content
+
+
+

graphene_django/decorators.py

@@ -0,0 +1,51 @@
+# coding: utf-8
+from functools import wraps
+from django.http import HttpResponseForbidden
+
+
+def has_perms(permissions):
+    """
+    Check if have user logged and permissions to see some value
+
+    Example:
+        class CityNode(DjangoObjectType):
+            class Meta(object):
+                interfaces = (relay.Node,)
+                model = City
+                only_fields = (
+                    'name', 'locality', 'slug', 'state', 'active',
+                )
+
+            @has_perms(["django_city_app.can_see_location"])
+            def resolve_location(self, args, context, info):
+                return self.locality.pos
+
+    Args:
+        permissions: ["django_app.permission_codename",]
+    """
+    def decorator(method):
+        if callable(permissions):
+            method.permissions = []
+        else:
+            method.permissions = permissions
+
+        @wraps(method)
+        def wrapper(*args, **kwargs):
+            context = kwargs.get('context', dict(zip(method.func_code.co_varnames,
+                                                     args)).get('context', None))
+            if not context:
+                return HttpResponseForbidden('Forbidden. No context, no access.')
+            try:
+                user = context.user
+            except AttributeError:
+                return HttpResponseForbidden('Forbidden. No request.')
+
+            if method.permissions and not user.has_perms(method.permissions):
+                return HttpResponseForbidden('Forbidden. User without access')
+            return method(*args, **kwargs)
+        return wrapper
+
+    if callable(permissions):
+        return decorator(permissions)
+
+    return decorator

graphene_django/tests/test_decorators.py

@@ -0,0 +1,80 @@
+# encoding: utf-8
+from django.utils.unittest import TestCase
+from ..decorators import has_perms
+
+
+class MockContext(object):
+    def __init__(self, authenticated=True, is_staff=False, superuser=False, perms=[]):
+        self.user = self
+        self.authenticated = authenticated
+        self.is_staff = is_staff
+        self.is_superuser = superuser
+        self.perms = perms
+        self.status_code = 200
+
+    def is_authenticated(self):
+        return self.authenticated
+
+    def has_perms(self, check_perms):
+        for perm in check_perms:
+            if perm not in self.perms:
+                return False
+        return True
+
+
+class TestHasPermsDecorator(TestCase):
+
+    @classmethod
+    @has_perms(['django_app.dummy_permission'])
+    def check_user_perms_func(cls, input, context, info=None):
+        cls.status_code = 200
+        cls.content = True
+        return cls
+
+    def test_get_content_without_permission(self):
+        context = MockContext(
+            authenticated=True
+        )
+        request = TestHasPermsDecorator.check_user_perms_func(None, context=context)
+        self.assertEqual(request.status_code, 403)
+        self.assertEqual(request.content, 'Forbidden. User without access')
+
+    def test_get_content_without_authentication(self):
+        context = MockContext(
+            authenticated=False
+        )
+        request = TestHasPermsDecorator.check_user_perms_func(None, context=context)
+        self.assertEqual(request.status_code, 403)
+        self.assertEqual(request.content, 'Forbidden. User is not authenticated.')
+
+    def test_get_context_with_permission(self):
+        context = MockContext(
+            authenticated=True,
+            perms=['django_app.dummy_permission']
+
+        )
+        request = TestHasPermsDecorator.check_user_perms_func(None, context=context)
+        self.assertEqual(request.status_code, 200)
+        self.assertEqual(request.content, True)
+
+    def test_get_context_with_diffent_and_valid_permission(self):
+        context = MockContext(
+            authenticated=True,
+            perms=['another_app.dummy_permission',
+                   'django_app.dummy_permission']
+
+        )
+        request = TestHasPermsDecorator.check_user_perms_func(None, context=context)
+        self.assertEqual(request.status_code, 200)
+        self.assertEqual(request.content, True)
+
+    def test_get_context_with_diffent_and_invalid_permission(self):
+        context = MockContext(
+            authenticated=True,
+            perms=['another_app.dummy_permission',
+                   'another_app.dummy_permission2']
+
+        )
+        request = TestHasPermsDecorator.check_user_perms_func(None, context=context)
+        self.assertEqual(request.status_code, 403)
+        self.assertEqual(request.content, 'Forbidden. User without access')