Add proper pagination

api/server/routes/aas.py

@@ -1,22 +1,23 @@
 from typing import Any
 
 from aas_core3.types import Identifiable
-from fastapi import APIRouter, Request
+from fastapi import APIRouter, Request, HTTPException
 
 from server.services.aas_service import AasService
-from server.utils.pagination import Pagination
 from basyx import ObjectStore
 
+from server.utils.decorator import paginated
 
-class AasRouter(Pagination):
+class AasRouter:
     def __init__(self, global_obj_store: ObjectStore[Identifiable]):
         self.router = APIRouter()
         self.service = AasService(global_obj_store)
         self._setup_routes()
 
     def _setup_routes(self):
         @self.router.get("/shells")
-        async def get_all_aas() -> Any:
+        @paginated()
+        async def get_all_aas(request: Request) -> Any:
             return self.service.get_all_shells_as_jsonable()
 
         @self.router.post("/shells")
@@ -26,7 +27,7 @@ async def create_aas(request: Request) -> Any:
 
         @self.router.get("/shells/$reference")
         async def get_all_aas_reference() -> Any:
-            return {"message": "Content parameters are not supported yet."}
+            raise HTTPException(status_code=501, detail="This route is not yet implemented!")
 
         @self.router.get("/shells/{aas_identifier}")
         async def get_aas_by_id(aas_identifier: str) -> Any:

api/server/routes/aas_registry_server.py

@@ -6,6 +6,8 @@
 from server.services.aas_registry_server_service import AasRegistryServerService
 from basyx import ObjectStore
 
+from server.utils.decorator import paginated
+
 
 class AasRegistryRouter:
     def __init__(self, global_obj_store: ObjectStore[Identifiable]):
@@ -16,7 +18,8 @@ def __init__(self, global_obj_store: ObjectStore[Identifiable]):
 
     def _setup_routes(self):
         @self.router.get("/")
-        async def get_all_aas_descriptors() -> Any:
+        @paginated()
+        async def get_all_aas_descriptors(request: Request) -> Any:
             return self.service.get_all_asset_administration_shell_descriptors()
 
         @self.router.get("/{aas_descriptor_id}")

api/server/routes/aasx_file_server.py

@@ -6,6 +6,8 @@
 from server.services.aasx_file_server_service import AasxFileServerService
 from basyx import ObjectStore
 
+from server.utils.decorator import paginated
+
 
 class AasxFileServerRouter:
     def __init__(self, global_obj_store: ObjectStore[Identifiable]):
@@ -16,7 +18,8 @@ def __init__(self, global_obj_store: ObjectStore[Identifiable]):
 
     def _setup_routes(self):
         @self.router.get("")
-        async def get_all_aasx() -> Any:
+        @paginated()
+        async def get_all_aasx(request: Request) -> Any:
             return self.service.get_all_aasx_package_ids()
 
         @self.router.get("/{aasx_package_id}")

api/server/routes/submodel.py

@@ -6,11 +6,10 @@
 from server.services.submodel_service import SubmodelService
 from basyx import ObjectStore
 
-from server.utils.pagination import Pagination
-from server.utils.decorator import limited
+from server.utils.decorator import paginated
 
 
-class SubmodelRouter(Pagination):
+class SubmodelRouter:
     def __init__(self, global_obj_store: ObjectStore[Identifiable]):
         self.router = APIRouter()
         self.obj_store = global_obj_store
@@ -20,24 +19,24 @@ def __init__(self, global_obj_store: ObjectStore[Identifiable]):
     def _setup_routes(self):
         # GetAllSubmodels and path-suffixes
         @self.router.get("")
-        @limited()
+        @paginated()
         async def get_submodel_all(request: Request) -> Any:
             return self.service.get_all_submodels_as_jsonables()
 
         @self.router.get("/$metadata")
-        @limited()
+        @paginated()
         async def get_submodel_all_metadata(request: Request) -> Any:
             # Returns metadata for all submodels, stripped of detailed content
             raise HTTPException(status_code=501, detail="This route is not yet implemented!")
 
         @self.router.get("/$reference")
-        @limited()
+        @paginated()
         async def get_submodel_all_reference(request: Request) -> Any:
             # Returns references for all submodels without full data
             raise HTTPException(status_code=501, detail="This route is not yet implemented!")
 
         @self.router.get("/$value")
-        @limited()
+        @paginated()
         async def not_implemented_value(request: Request) -> Any:
             raise HTTPException(status_code=501, detail="This route is not implemented!")
 
@@ -99,7 +98,8 @@ async def post_submodel_elements(submodel_identifier: str, request: Request) ->
             return self.service.post_submodel_element(submodel_identifier, body)
 
         @self.router.get("/{submodel_identifier}/submodel-elements")
-        async def get_submodel_submodel_elements(submodel_identifier: str) -> Any:
+        @paginated()
+        async def get_submodel_submodel_elements(request: Request, submodel_identifier: str) -> Any:
             # Get submodel elements
             self.service.get_submodel_elements(submodel_identifier)
 
@@ -121,7 +121,8 @@ async def not_implemented_submodel_elements_path(submodel_identifier: str) -> An
             raise HTTPException(status_code=501, detail="This route is not yet implemented!")
 
         @self.router.get("/{submodel_identifier}/submodel-elements/{id_short_path}")
-        async def get_submodel_submodel_elements_id_short_path(submodel_identifier: str, id_short_path: str) -> Any:
+        @paginated()
+        async def get_submodel_submodel_elements_id_short_path(request: Request, submodel_identifier: str, id_short_path: str) -> Any:
             return self.service.get_submodel_element(submodel_identifier, id_short_path)
 
         @self.router.post("/{submodel_identifier}/submodel-elements/{id_short_path}")

api/server/routes/submodel_registry_server.py

@@ -6,6 +6,8 @@
 from server.services.submodel_registry_server_service import SubmodelRegistryServerService
 from basyx import ObjectStore
 
+from server.utils.decorator import paginated
+
 
 class SubmodelRegistryRouter:
     def __init__(self, global_obj_store: ObjectStore[Identifiable]):
@@ -16,7 +18,8 @@ def __init__(self, global_obj_store: ObjectStore[Identifiable]):
 
     def _setup_routes(self):
         @self.router.get("/")
-        async def get_all_submodel_descriptors() -> Any:
+        @paginated()
+        async def get_all_submodel_descriptors(request: Request) -> Any:
             return self.service.get_all_submodel_descriptors()
 
         @self.router.get("/{submodel_id}")

api/server/utils/decorator.py

@@ -1,28 +1,36 @@
 from functools import wraps
 from fastapi import Request
-from typing import Callable, Any, Union
+from typing import Callable, Any, Union, Tuple
 
 
-def limited(default_limit: int = 100):
+def paginated(default_limit: int = 100):
     def decorator(func: Callable):
         @wraps(func)
         async def wrapper(*args, **kwargs) -> Any:
-            # Extract request from kwargs (FastAPI automatically passes it)
             request: Request = kwargs.get("request")
-            limit: Union[str, int] = request.query_params.get("limit", default_limit)
+            query = request.query_params
 
             try:
-                limit = int(limit)  # Ensure limit is an integer
+                limit = int(query.get("limit", default_limit))
+                cursor = int(query.get("cursor", 0))
+                if limit < 0 or cursor < 0:
+                    raise ValueError
             except ValueError:
-                limit = default_limit  # Fallback if conversion fails
+                from fastapi import HTTPException
+                raise HTTPException(status_code=400, detail="Cursor and limit must be >0")
 
-            # Call the original function
             result = await func(*args, **kwargs)
 
-            # Apply limit if the result is a list
             if isinstance(result, list):
-                return result[:limit]
-            return result  # If not a list, return as-is
+                # FIXME: Is this correct? Following Spec p.119
+                return {
+                    "result": result[cursor:cursor + limit],
+                    "paging_metadata": {
+                        "next_cursor": cursor + limit if cursor + limit < len(result) else None
+                    }
+                }
+
+            return result
 
         return wrapper
 

api/test/__init__.py

@@ -0,0 +1,7 @@
+def wrap_paginated(result):
+    return {
+        "result": result,
+        "paging_metadata": {
+            "next_cursor": None
+        }
+    }

api/test/examples/empty_paged_result.json

@@ -0,0 +1,6 @@
+{
+  "result": [],
+  "paging_metadata": {
+    "next_cursor": null
+  }
+}

api/test/examples/submodel/submodel2.json

@@ -0,0 +1,37 @@
+{
+    "id": "urn:x-test:submodel2",
+    "submodelElements": [
+        {
+            "idShort": "some_property",
+            "valueType": "xs:int",
+            "value": "1984",
+            "modelType": "Property"
+        },
+        {
+            "idShort": "some_blob",
+            "value": "3q2+7w==",
+            "contentType": "application/octet-stream",
+            "modelType": "Blob"
+        },
+        {
+            "idShort": "ExampleSubmodelList",
+            "typeValueListElement": "SubmodelElementList",
+            "value": [
+                {
+                    "idShort": "list_1",
+                    "value": "3q2+7w==",
+                    "contentType": "application/octet-stream",
+                    "modelType": "Blob"
+                },
+                {
+                    "idShort": "list_2",
+                    "value": "3q2+7w==",
+                    "contentType": "application/octet-stream",
+                    "modelType": "Blob"
+                }
+            ],
+            "modelType": "SubmodelElementList"
+        }
+    ],
+    "modelType": "Submodel"
+}

api/test/test_aas_service.py

@@ -5,6 +5,8 @@
 
 from server import app
 
+from test import wrap_paginated
+
 BASE_URL = "/api/v3.0/"
 
 
@@ -31,6 +33,9 @@ def setUp(self):
         with open(os.path.join(base_path, "examples/aas", "thumbnail_modified.json"), encoding="utf-8") as f:
             self.thumbnail_example_modified = json.load(f)
 
+        with open(os.path.join(base_path, "examples", "empty_paged_result.json"), encoding="utf-8") as f:
+            self.empty_result = json.load(f)
+
         # FIXME: modified AAS should contain more complex types but deserialization seems to fail
         with open(os.path.join(base_path, "examples/aas", "aas_modified.json"), encoding="utf-8") as f:
             self.aas_example_modified = json.load(f)
@@ -48,14 +53,14 @@ def test_aas_post(self):
     def test_get_all_shells(self):
         response = self.client.get(BASE_URL + "aas/shells")
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json(), [])
+        self.assertEqual(response.json(), self.empty_result)
 
         # Setup
         self.client.post(BASE_URL + "aas/shells", json=self.aas_example)
 
         response = self.client.get(BASE_URL + "aas/shells")
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json(), [self.aas_example])
+        self.assertEqual(response.json(), wrap_paginated([self.aas_example]))
 
         # Teardown
         self.client.delete(BASE_URL + "ass/shells/" + self.shell_example_id)

api/test/test_aasx_file_server_service.py

@@ -6,6 +6,8 @@
 from server import app
 from aas_core3 import jsonization
 
+from test import wrap_paginated
+
 client = TestClient(app)
 BASE_URL = "/api/v3.0/"
 
@@ -18,21 +20,25 @@ def setUp(self):
         with open(os.path.join(base_path, "examples/aasx", "aasx.json"), encoding="utf-8") as f:
             self.aasx_json = json.load(f)
 
+        with open(os.path.join(base_path, "examples", "empty_paged_result.json"), encoding="utf-8") as f:
+            self.empty_result = json.load(f)
+
+
         self.test_aasx_id = self.aasx_json["id"]
         self.aasx = jsonization.asset_administration_shell_from_jsonable(self.aasx_json)
 
     def test_get_all_aasx_package_ids(self):
         # Test empty
         response = self.client.get(BASE_URL + "aasx")
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json(), [])
+        self.assertEqual(response.json(), self.empty_result)
 
         # Setup
         self.client.post(BASE_URL + "aasx", json=self.aasx_json)
 
         response = self.client.get(BASE_URL + "aasx")
         self.assertEqual(response.status_code, 200)
-        self.assertEqual(response.json(), [self.test_aasx_id])
+        self.assertEqual(response.json(), wrap_paginated([self.test_aasx_id]))
 
         # Teardown
         self.client.delete(BASE_URL + "aasx/" + self.test_aasx_id)