Implement Task AB#3095678 - Define Measurement Script API (#2)

* first draft

* add basic tests

* cleanup

* address feedback

* refactor to use _StreamlitPanel subclass

* refactor to make StreamlitPanel public instead of Panel

* make Panel public also, for type hints

* panel_id should be specified by the user. Also, lets provide readonly accessors for that and panel_uri.

* put panel_id berfore panel_uri

---------

Co-authored-by: Mike Prosser <Mike.Prosser@emerson.com>

Author: mikeprosserni

.vscode/settings.json

@@ -0,0 +1,7 @@
+{
+    "python.testing.pytestArgs": [
+        "."
+    ],
+    "python.testing.unittestEnabled": false,
+    "python.testing.pytestEnabled": true
+}

pyproject.toml

@@ -52,3 +52,7 @@ ignore_missing_imports = true
 skips = [
   "B101", # assert_used
 ]
+
+[tool.pytest.ini_options]
+addopts = "--doctest-modules --strict-markers"
+testpaths = ["src/nipanel", "tests"]

src/nipanel/__init__.py

@@ -1 +1,10 @@
 """The NI Panel."""
+
+from nipanel._panel import Panel
+from nipanel._streamlit_panel import StreamlitPanel
+
+__all__ = ["Panel", "StreamlitPanel"]
+
+# Hide that it was defined in a helper file
+Panel.__module__ = __name__
+StreamlitPanel.__module__ = __name__

src/nipanel/_panel.py

@@ -0,0 +1,91 @@
+from __future__ import annotations
+
+import sys
+from abc import ABC, abstractmethod
+from types import TracebackType
+from typing import Optional, Type, TYPE_CHECKING
+
+from ni.pythonpanel.v1.python_panel_service_pb2_grpc import PythonPanelServiceStub
+
+if TYPE_CHECKING:
+    if sys.version_info >= (3, 11):
+        from typing import Self
+    else:
+        from typing_extensions import Self
+
+
+class Panel(ABC):
+    """This class allows you to connect to a panel and specify values for its controls."""
+
+    _stub: PythonPanelServiceStub | None
+    _panel_id: str
+    _panel_uri: str
+
+    __slots__ = ["_stub", "_panel_id", "_panel_uri", "__weakref__"]
+
+    def __init__(self, panel_id: str, panel_uri: str) -> None:
+        """Initialize the panel."""
+        self._panel_id = panel_id
+        self._panel_uri = panel_uri
+
+    @property
+    def panel_id(self) -> str:
+        """Read-only accessor for the panel ID."""
+        return self._panel_id
+
+    @property
+    def panel_uri(self) -> str:
+        """Read-only accessor for the panel URI."""
+        return self._panel_uri
+
+    def __enter__(self) -> Self:
+        """Enter the runtime context related to this object."""
+        self.connect()
+        return self
+
+    def __exit__(
+        self,
+        exctype: Optional[Type[BaseException]],
+        excinst: Optional[BaseException],
+        exctb: Optional[TracebackType],
+    ) -> Optional[bool]:
+        """Exit the runtime context related to this object."""
+        self.disconnect()
+        return None
+
+    def connect(self) -> None:
+        """Connect to the panel and open it."""
+        # TODO: AB#3095680 - Use gRPC pool management, create the _stub, and call _stub.Connect
+        self._resolve_service_location()
+
+    def disconnect(self) -> None:
+        """Disconnect from the panel (does not close the panel)."""
+        # TODO: AB#3095680 - Use gRPC pool management, call _stub.Disconnect
+        pass
+
+    def get_value(self, value_id: str) -> object:
+        """Get the value for a control on the panel.
+
+        Args:
+            value_id: The id of the value
+
+        Returns:
+            The value
+        """
+        # TODO: AB#3095681 - get the Any from _stub.GetValue and convert it to the correct type
+        return "placeholder value"
+
+    def set_value(self, value_id: str, value: object) -> None:
+        """Set the value for a control on the panel.
+
+        Args:
+            value_id: The id of the value
+            value: The value
+        """
+        # TODO: AB#3095681 - Convert the value to an Any and pass it to _stub.SetValue
+        pass
+
+    @abstractmethod
+    def _resolve_service_location(self) -> str:
+        """Resolve the service location for the panel."""
+        raise NotImplementedError

src/nipanel/_streamlit_panel.py

@@ -0,0 +1,23 @@
+from nipanel._panel import Panel
+
+
+class StreamlitPanel(Panel):
+    """This class allows you to connect to a Streamlit panel and specify values for its controls."""
+
+    __slots__ = ()
+
+    def __init__(self, panel_id: str, streamlit_script_uri: str) -> None:
+        """Create a panel using a Streamlit script for the user interface.
+
+        Args:
+            panel_id: A unique identifier for the panel.
+            streamlit_script_uri: The file path of the Streamlit script.
+
+        Returns:
+            A new StreamlitPanel instance.
+        """
+        super().__init__(panel_id, streamlit_script_uri)
+
+    def _resolve_service_location(self) -> str:
+        # TODO: AB#3095680 - resolve to the Streamlit PythonPanelService
+        return ""

tests/__init__.py

@@ -0,0 +1 @@
+"""Tests for the `nipanel` package."""

tests/unit/test_panel.py

@@ -0,0 +1,27 @@
+import nipanel
+
+
+def test___streamlit_panel___has_panel_id_and_panel_uri() -> None:
+    panel = nipanel.StreamlitPanel("my_panel", "path/to/script")
+    assert panel.panel_id == "my_panel"
+    assert panel.panel_uri == "path/to/script"
+
+
+def test___connected_panel___set_value___gets_same_value() -> None:
+    panel = nipanel.StreamlitPanel("my_panel", "path/to/script")
+    panel.connect()
+
+    panel.set_value("test_id", "test_value")
+
+    # TODO: AB#3095681 - change asserted value to test_value
+    assert panel.get_value("test_id") == "placeholder value"
+    panel.disconnect()
+
+
+def test___with_panel___set_value___gets_same_value() -> None:
+    with nipanel.StreamlitPanel("my_panel", "path/to/script") as panel:
+
+        panel.set_value("test_id", "test_value")
+
+        # TODO: AB#3095681 - change asserted value to test_value
+        assert panel.get_value("test_id") == "placeholder value"