BaseView.check_permissions is now datasette.ensure_permissions, closes #1675

Refs #1660

datasette/app.py

@@ -1,4 +1,5 @@
 import asyncio
+from typing import Sequence, Union, Tuple
 import asgi_csrf
 import collections
 import datetime
@@ -628,6 +629,40 @@ class Datasette:
         )
         return result
 
+    async def ensure_permissions(
+        self,
+        actor: dict,
+        permissions: Sequence[Union[Tuple[str, Union[str, Tuple[str, str]]], str]],
+    ):
+        """
+        permissions is a list of (action, resource) tuples or 'action' strings
+
+        Raises datasette.Forbidden() if any of the checks fail
+        """
+        for permission in permissions:
+            if isinstance(permission, str):
+                action = permission
+                resource = None
+            elif isinstance(permission, (tuple, list)) and len(permission) == 2:
+                action, resource = permission
+            else:
+                assert (
+                    False
+                ), "permission should be string or tuple of two items: {}".format(
+                    repr(permission)
+                )
+            ok = await self.permission_allowed(
+                actor,
+                action,
+                resource=resource,
+                default=None,
+            )
+            if ok is not None:
+                if ok:
+                    return
+                else:
+                    raise Forbidden(action)
+
     async def execute(
         self,
         db_name,

datasette/views/base.py

@@ -76,32 +76,6 @@ class BaseView:
         if not ok:
             raise Forbidden(action)
 
-    async def check_permissions(self, request, permissions):
-        """permissions is a list of (action, resource) tuples or 'action' strings"""
-        for permission in permissions:
-            if isinstance(permission, str):
-                action = permission
-                resource = None
-            elif isinstance(permission, (tuple, list)) and len(permission) == 2:
-                action, resource = permission
-            else:
-                assert (
-                    False
-                ), "permission should be string or tuple of two items: {}".format(
-                    repr(permission)
-                )
-            ok = await self.ds.permission_allowed(
-                request.actor,
-                action,
-                resource=resource,
-                default=None,
-            )
-            if ok is not None:
-                if ok:
-                    return
-                else:
-                    raise Forbidden(action)
-
     def database_color(self, database):
         return "ff0000"
 

datasette/views/database.py

@@ -39,8 +39,8 @@ class DatabaseView(DataView):
             raise NotFound("Database not found: {}".format(database_route))
         database = db.name
 
-        await self.check_permissions(
-            request,
+        await self.ds.ensure_permissions(
+            request.actor,
             [
                 ("view-database", database),
                 "view-instance",
@@ -164,8 +164,8 @@ class DatabaseDownload(DataView):
 
     async def get(self, request):
         database = tilde_decode(request.url_vars["database"])
-        await self.check_permissions(
-            request,
+        await self.ds.ensure_permissions(
+            request.actor,
             [
                 ("view-database-download", database),
                 ("view-database", database),
@@ -217,8 +217,8 @@ class QueryView(DataView):
         private = False
         if canned_query:
             # Respect canned query permissions
-            await self.check_permissions(
-                request,
+            await self.ds.ensure_permissions(
+                request.actor,
                 [
                     ("view-query", (database, canned_query)),
                     ("view-database", database),

datasette/views/table.py

@@ -360,8 +360,8 @@ class TableView(RowTableShared):
             raise NotFound(f"Table not found: {table}")
 
         # Ensure user has permission to view this table
-        await self.check_permissions(
-            request,
+        await self.ds.ensure_permissions(
+            request.actor,
             [
                 ("view-table", (database, table)),
                 ("view-database", database),
@@ -950,8 +950,8 @@ class RowView(RowTableShared):
         except KeyError:
             raise NotFound("Database not found: {}".format(database_route))
         database = db.name
-        await self.check_permissions(
-            request,
+        await self.ds.ensure_permissions(
+            request.actor,
             [
                 ("view-table", (database, table)),
                 ("view-database", database),

docs/internals.rst

@@ -295,6 +295,32 @@ If neither ``metadata.json`` nor any of the plugins provide an answer to the per
 
 See :ref:`permissions` for a full list of permission actions included in Datasette core.
 
+.. _datasette_permission_allowed:
+
+await .ensure_permissions(actor, permissions)
+---------------------------------------------
+
+``actor`` - dictionary
+    The authenticated actor. This is usually ``request.actor``.
+
+``permissions`` - list
+    A list of permissions to check. Each permission in that list can be a string ``action`` name or a 2-tuple of ``(action, resource)``.
+
+This method allows multiple permissions to be checked at onced. It raises a ``datasette.Forbidden`` exception if any of the checks are denied before one of them is explicitly granted.
+
+This is useful when you need to check multiple permissions at once. For example, an actor should be able to view a table if either one of the following checks returns ``True`` or not a single one of them returns ``False``:
+
+.. code-block:: python
+
+    await self.ds.ensure_permissions(
+        request.actor,
+        [
+            ("view-table", (database, table)),
+            ("view-database", database),
+            "view-instance",
+        ]
+    )
+
 .. _datasette_get_database:
 
 .get_database(name)