Implement lid support

Author: Jackie Greenbaum

atomic_operations/parsers.py

@@ -43,12 +43,24 @@ class AtomicOperationParser(JSONParser):
     renderer_class = renderers.JSONRenderer
 
     def check_resource_identifier_object(self, idx: int, resource_identifier_object: Dict, operation_code: str):
-        if operation_code in ["update", "remove"] and not resource_identifier_object.get("id"):
-            raise JsonApiParseError(
-                id="missing-id",
-                detail="The resource identifier object must contain an `id` member",
-                pointer=f"/{ATOMIC_OPERATIONS}/{idx}/{'data' if operation_code == 'update' else 'ref'}"
-            )
+        if operation_code in ["update", "remove"]:
+            resource_id = resource_identifier_object.get("id")
+            resource_lid = resource_identifier_object.get("lid")
+
+            if not (resource_id or resource_lid):
+                raise JsonApiParseError(
+                    id="missing-id",
+                    detail="The resource identifier object must contain an `id` member or a `lid` member",
+                    pointer=f"/{ATOMIC_OPERATIONS}/{idx}/{'data' if operation_code == 'update' else 'ref'}"
+                )
+            
+            if resource_id and resource_lid:
+                raise JsonApiParseError(
+                    id="multiple-id-fields",
+                    detail="Only one of `id`, `lid` may be specified",
+                    pointer=f"/{ATOMIC_OPERATIONS}/{idx}/{'data' if operation_code == 'update' else 'ref'}"
+                )
+
         if not resource_identifier_object.get("type"):
             raise JsonApiParseError(
                 id="missing-type",
@@ -150,10 +162,14 @@ def check_operation(self, idx: int, operation: Dict):
                 pointer=f"/{ATOMIC_OPERATIONS}/{idx}/op"
             )
 
-    def parse_id_and_type(self, resource_identifier_object):
+    def parse_id_lid_and_type(self, resource_identifier_object):
         parsed_data = {"id": resource_identifier_object.get(
             "id")} if "id" in resource_identifier_object else {}
         parsed_data["type"] = resource_identifier_object.get("type")
+
+        if lid := resource_identifier_object.get("lid", None):
+            parsed_data["lid"] = lid
+    
         return parsed_data
 
     def check_root(self, result):
@@ -173,7 +189,7 @@ def check_root(self, result):
             )
 
     def parse_operation(self, resource_identifier_object, result):
-        _parsed_data = self.parse_id_and_type(resource_identifier_object)
+        _parsed_data = self.parse_id_lid_and_type(resource_identifier_object)
         _parsed_data.update(self.parse_attributes(resource_identifier_object))
         _parsed_data.update(self.parse_relationships(resource_identifier_object))
         _parsed_data.update(self.parse_metadata(result))

atomic_operations/views.py

@@ -1,4 +1,5 @@
 from typing import Dict, List
+from collections import defaultdict
 
 from django.core.exceptions import ImproperlyConfigured, ObjectDoesNotExist
 from django.db.transaction import atomic
@@ -27,6 +28,8 @@ class AtomicOperationView(APIView):
     sequential = True
     response_data: List[Dict] = []
 
+    lid_to_id = defaultdict(dict)
+
     # TODO: proof how to check permissions for all operations
     # permission_classes = TODO
     # call def check_permissions for `add` operation
@@ -94,8 +97,15 @@ def post(self, request, *args, **kwargs):
 
     def handle_sequential(self, serializer, operation_code):
         if operation_code in ["add", "update", "update-relationship"]:
+            lid = serializer.initial_data.get("lid", None)
+
             serializer.is_valid(raise_exception=True)
             serializer.save()
+
+            if operation_code == "add" and lid:
+                resource_type = serializer.initial_data["type"]
+                self.lid_to_id[resource_type][lid] = serializer.data["id"]
+
             if operation_code != "update-relationship":
                 self.response_data.append(serializer.data)
         else:
@@ -139,6 +149,36 @@ def handle_bulk(self, serializer, current_operation_code, bulk_operation_data):
                     bulk_operation_data["serializer_collection"][0], current_operation_code)
             bulk_operation_data["serializer_collection"] = []
 
+    def substitute_lids(self, data, idx, should_raise_unknown_lid_error):
+        if not isinstance(data, dict):
+            return
+
+        try:
+            lid = data.get("lid", None)
+            if lid:
+                resource_type = data["type"]
+                data["id"] = self.lid_to_id[resource_type][lid]
+        except KeyError:
+            if should_raise_unknown_lid_error:
+                raise UnprocessableEntity([
+                    {
+                        "id": "unknown-lid",
+                        "detail": f'Object with lid `{lid}` received for operation with index `{idx}` does not exist',
+                        "source": {
+                            "pointer": f"/{ATOMIC_OPERATIONS}/{idx}/data/lid"
+                        },
+                        "status": "422"
+                    }
+                ])
+            
+        for _, value in data.items():
+            if isinstance(value, dict):
+                self.substitute_lids(value, idx, should_raise_unknown_lid_error=True)
+            elif isinstance(value, list):
+                [self.substitute_lids(value, idx, should_raise_unknown_lid_error=True) for value in value]
+
+        return data     
+        
     def perform_operations(self, parsed_operations: List[Dict]):
         self.response_data = []  # reset local response data storage
 
@@ -154,6 +194,9 @@ def perform_operations(self, parsed_operations: List[Dict]):
                 operation_code = next(iter(operation))
                 obj = operation[operation_code]
 
+                should_raise_unknown_lid_error = operation_code != "add"
+                self.substitute_lids(obj, idx, should_raise_unknown_lid_error)
+
                 serializer = self.get_serializer(
                     idx=idx,
                     data=obj,