Use ServeDocsPermissionsMixin to isolate this methods and be more clear

Author: humitos

readthedocs/proxito/views/mixins.py

@@ -154,3 +154,37 @@ def get_redirect_response(self, request, redirect_path, http_status):
             return HttpResponsePermanentRedirect(new_path)
 
         return HttpResponseRedirect(new_path)
+
+
+class ServeDocPermissionsMixin:
+    """
+    Mixin to handle documentation permissions.
+
+    To use this mixin, the method that serve the docs should call
+    ``allowed_user`` first to check if the user requesting to read the page is
+    allowed. If allowed, the flow should continue.
+
+    On the other hand, if the user is not allowed, the serve docs method MUST
+    break the flow and return a call to ``get_unauthed_response``.
+    """
+
+    def allowed_user(self, request, project, version_slug):
+        """
+        Return whether the user is allowed to read this documentation's version.
+
+        :returns: ``True`` if allowed. ``False`` otherwise.
+        :rtype: bool
+        """
+        return False
+
+    def get_unauthed_response(self, request, project):
+        """
+        Return response for an unauthed hit at a documentation's version.
+
+        When a user does not have access to read documentation, we need to
+        return a response showing the proper message. This method produces that
+        reponse.
+
+        :rtype: django.http.HttpResponse
+        """
+        return self._serve_401(request, project)

readthedocs/proxito/views/serve.py

@@ -20,7 +20,11 @@
 from readthedocs.projects import constants
 from readthedocs.projects.templatetags.projects_tags import sort_version_aware
 
-from .mixins import ServeDocsMixin, ServeRedirectMixin
+from .mixins import (
+    ServeDocsMixin,
+    ServeRedirectMixin,
+    ServeDocsPermissionsMixin,
+)
 
 from .decorators import map_project_slug
 from .redirects import redirect_project_slug
@@ -30,7 +34,12 @@
 log = logging.getLogger(__name__)  # noqa
 
 
-class ServeDocsBase(ServeRedirectMixin, ServeDocsMixin, View):
+class ServeDocsBase(
+        ServeRedirectMixin,
+        ServeDocsPermissionsMixin,
+        ServeDocsMixin,
+        View,
+):
 
     def get(self,
             request,
@@ -108,7 +117,7 @@ def get(self,
             path=path,
         )
 
-    def allowed_user(self, *args, **kwargs):
+    def allowed_user(self, *args, **kwargs):  # noqa
         return True