Merge branch 'mb/filter' into develop

2 files changed, 9 insertions, 0 deletions

diff --git a/bsfs/graph/ac/base.py b/bsfs/graph/ac/base.py
index bc9aeb3..0703e2e 100644
--- a/bsfs/graph/ac/base.py
+++ b/bsfs/graph/ac/base.py
@@ -10,6 +10,7 @@ import typing
 
 # bsfs imports
 from bsfs import schema
+from bsfs.query import ast
 from bsfs.triple_store import TripleStoreBase
 from bsfs.utils import URI
 
@@ -67,5 +68,8 @@ class AccessControlBase(abc.ABC):
     def createable(self, node_type: schema.Node, guids: typing.Iterable[URI]) -> typing.Iterable[URI]:
         """Return nodes that are allowed to be created."""
 
+    @abc.abstractmethod
+    def filter_read(self, node_type: schema.Node, query: ast.filter.FilterExpression) -> ast.filter.FilterExpression:
+        """Re-write a filter *query* to get (i.e., read) *node_type* nodes."""
 
 ## EOF ##
diff --git a/bsfs/graph/ac/null.py b/bsfs/graph/ac/null.py
index 36838bd..12b4e87 100644
--- a/bsfs/graph/ac/null.py
+++ b/bsfs/graph/ac/null.py
@@ -10,6 +10,7 @@ import typing
 # bsfs imports
 from bsfs import schema
 from bsfs.namespace import ns
+from bsfs.query import ast
 from bsfs.utils import URI
 
 # inner-module imports
@@ -49,4 +50,8 @@ class NullAC(base.AccessControlBase):
         """Return nodes that are allowed to be created."""
         return guids
 
+    def filter_read(self, node_type: schema.Node, query: ast.filter.FilterExpression) -> ast.filter.FilterExpression:
+        """Re-write a filter *query* to get (i.e., read) *node_type* nodes."""
+        return query
+
 ## EOF ##