GetValueResponse.found

Author: Mike Prosser

examples/simple_graph/simple_graph.py

@@ -21,6 +21,9 @@
 
     # Generate and update the sine wave data periodically
     while True:
+        # not-found values need to be performant
+        not_found = panel.get_value("no_such_value", "Hello, World!")
+
         amplitude_enum = panel.get_value("amplitude_enum", AmplitudeEnum.SMALL)
         base_frequency = panel.get_value("base_frequency", 1.0)
 

protos/ni/pythonpanel/v1/python_panel_service.proto

@@ -100,6 +100,9 @@ message GetValueRequest {
 message GetValueResponse {
   // The value
   google.protobuf.Any value = 1;
+
+  // Was the value found?
+  bool found = 2;
 }
 
 message SetValueRequest {

src/ni/pythonpanel/v1/python_panel_service_pb2.py

@@ -162,6 +162,9 @@ class GetValueResponse(google.protobuf.message.Message):
     DESCRIPTOR: google.protobuf.descriptor.Descriptor
 
     VALUE_FIELD_NUMBER: builtins.int
+    FOUND_FIELD_NUMBER: builtins.int
+    found: builtins.bool
+    """Was the value found?"""
     @property
     def value(self) -> google.protobuf.any_pb2.Any:
         """The value"""
@@ -170,9 +173,10 @@ class GetValueResponse(google.protobuf.message.Message):
         self,
         *,
         value: google.protobuf.any_pb2.Any | None = ...,
+        found: builtins.bool = ...,
     ) -> None: ...
     def HasField(self, field_name: typing.Literal["value", b"value"]) -> builtins.bool: ...
-    def ClearField(self, field_name: typing.Literal["value", b"value"]) -> None: ...
+    def ClearField(self, field_name: typing.Literal["found", b"found", "value", b"value"]) -> None: ...
 
 global___GetValueResponse = GetValueResponse
 

src/ni/pythonpanel/v1/python_panel_service_pb2.pyi

@@ -116,7 +116,7 @@ def set_value(self, panel_id: str, value_id: str, value: object, notify: bool) -
         )
         self._invoke_with_retry(self._get_stub().SetValue, set_value_request)
 
-    def get_value(self, panel_id: str, value_id: str) -> object:
+    def get_value(self, panel_id: str, value_id: str) -> tuple[bool, object]:
         """Get the value for the control with value_id.
 
         Args:
@@ -128,8 +128,10 @@ def get_value(self, panel_id: str, value_id: str) -> object:
         """
         get_value_request = GetValueRequest(panel_id=panel_id, value_id=value_id)
         response = self._invoke_with_retry(self._get_stub().GetValue, get_value_request)
+        if not response.found:
+            return False, None
         the_value = from_any(response.value)
-        return the_value
+        return True, the_value
 
     def _get_stub(self) -> PythonPanelServiceStub:
         if self._stub is None:

src/nipanel/_panel_client.py

@@ -61,25 +61,22 @@ def get_value(self, value_id: str, default_value: _T | None = None) -> _T | obje
         Returns:
             The value, or the default value if not set
         """
-        try:
-            value = self._panel_client.get_value(self._panel_id, value_id)
-
-            if default_value is not None and not isinstance(value, type(default_value)):
-                if isinstance(default_value, enum.Enum):
-                    enum_type = type(default_value)
-                    return enum_type(value)
+        found, value = self._panel_client.get_value(self._panel_id, value_id)
+        if not found:
+            if default_value is not None:
+                return default_value
+            raise KeyError(f"Value with id '{value_id}' not found on panel '{self._panel_id}'.")
 
-                raise TypeError(
-                    f"Value type {type(value).__name__} does not match default value type {type(default_value).__name__}."
-                )
+        if default_value is not None and not isinstance(value, type(default_value)):
+            if isinstance(default_value, enum.Enum):
+                enum_type = type(default_value)
+                return enum_type(value)
 
-            return value
+            raise TypeError(
+                f"Value type {type(value).__name__} does not match default value type {type(default_value).__name__}."
+            )
 
-        except grpc.RpcError as e:
-            if e.code() == grpc.StatusCode.NOT_FOUND and default_value is not None:
-                return default_value
-            else:
-                raise e
+        return value
 
     def set_value(self, value_id: str, value: object) -> None:
         """Set the value for a control on the panel.

src/nipanel/_panel_value_accessor.py

@@ -79,7 +79,7 @@ def _initialize_panel_from_base_path() -> StreamlitPanelValueAccessor:
     return StreamlitPanelValueAccessor(panel_id)
 
 
-def _sync_session_state(panel):
+def _sync_session_state(panel: StreamlitPanelValueAccessor) -> None:
     """Automatically read keyed control values from the session state."""
     for key in st.session_state.keys():
         value = st.session_state[key]

src/nipanel/_streamlit_panel_initializer.py

@@ -1,5 +1,4 @@
 import grpc
-import pytest
 
 from nipanel._panel_client import PanelClient
 
@@ -51,11 +50,12 @@ def test___start_panels___stop_panel_1_without_reset___enumerate_has_both_panels
     }
 
 
-def test___get_unset_value_raises_exception(fake_panel_channel: grpc.Channel) -> None:
+def test___get_unset_value___returns_not_found(fake_panel_channel: grpc.Channel) -> None:
     client = create_panel_client(fake_panel_channel)
 
-    with pytest.raises(Exception):
-        client.get_value("panel1", "unset_id")
+    response = client.get_value("panel1", "unset_id")
+
+    assert response == (False, None)
 
 
 def test___set_value___enumerate_panels_shows_value(
@@ -73,7 +73,7 @@ def test___set_value___gets_value(fake_panel_channel: grpc.Channel) -> None:
 
     client.set_value("panel1", "val1", "value1", notify=False)
 
-    assert client.get_value("panel1", "val1") == "value1"
+    assert client.get_value("panel1", "val1") == (True, "value1")
 
 
 def create_panel_client(fake_panel_channel: grpc.Channel) -> PanelClient:

tests/unit/test_panel_client.py

@@ -131,7 +131,7 @@ def test___panel___get_unset_value_with_no_default___raises_exception(
     panel = StreamlitPanel("my_panel", "path/to/script", grpc_channel=fake_panel_channel)
 
     value_id = "test_id"
-    with pytest.raises(grpc.RpcError):
+    with pytest.raises(KeyError):
         panel.get_value(value_id)
 
 

tests/unit/test_streamlit_panel.py

@@ -62,9 +62,9 @@ def EnumeratePanels(  # noqa: N802
     def GetValue(self, request: GetValueRequest, context: Any) -> GetValueResponse:  # noqa: N802
         """Trivial implementation for testing."""
         if request.value_id not in self._panel_value_ids.get(request.panel_id, {}):
-            context.abort(grpc.StatusCode.NOT_FOUND, "Value ID not found in panel")
+            return GetValueResponse(found=False)
         value = self._panel_value_ids[request.panel_id][request.value_id]
-        return GetValueResponse(value=value)
+        return GetValueResponse(found=True, value=value)
 
     def SetValue(self, request: SetValueRequest, context: Any) -> SetValueResponse:  # noqa: N802
         """Trivial implementation for testing."""