raise exception on duplicate binding, refactor (47dfdb34) · Commits · NDIP / Nova Packages / nova-mvvm

src/nova/mvvm/_internal/utils.py

+11 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,9 @@
		import re
		from typing import Any, Dict

		from nova.mvvm import bindings_map
		from nova.mvvm.interface import LinkedObjectType


		def normalize_field_name(field: str) -> str:
		return field.replace(".", "_").replace("[", "_").replace("]", "")
		@@ -87,3 +90,11 @@ def rgetdictvalue(obj: Dict[str, Any], field: str) -> Any:
		for index in indices:
		obj = obj[index]
		return obj


		def check_binding(linked_object: LinkedObjectType, name: str) -> None:
		if name in bindings_map:
		raise ValueError(f"cannot connect to binding {name}: name already used")
		for communicator in bindings_map.values():
		if communicator.viewmodel_linked_object and communicator.viewmodel_linked_object == linked_object:
		raise ValueError(f"cannot connect to binding {name}: object already connected")

src/nova/mvvm/interface.py

+1 −1

Original line number	Diff line number	Diff line
		@@ -18,7 +18,7 @@ class Communicator(ABC):
		"""

		@abstractmethod
		def connect(self, connector: Any = None) -> ConnectCallbackType:
		def connect(self, *args: Any) -> ConnectCallbackType:
		"""
		Connect a GUI element to a linked object.

src/nova/mvvm/pyqt_binding/binding.py

+20 −10

Original line number	Diff line number	Diff line
		"""Binding module for PyQt framework."""

		import os
		from typing import Any, Callable, Optional
		from typing import Any, Optional

		from pydantic import BaseModel, ValidationError
		from typing_extensions import override

		from .._internal.pydantic_utils import get_errored_fields_from_validation_error, get_updated_fields
		from .._internal.utils import rsetattr
		from .._internal.utils import check_binding, rsetattr
		from ..bindings_map import bindings_map

		if os.environ.get("QT_API", None) == "pyqt5":
		@@ -24,18 +25,22 @@ else:

		import inspect

		from ..interface import BindingInterface
		from ..interface import BindingInterface, Communicator, ConnectCallbackType


		def is_callable(var: Any) -> bool:
		return inspect.isfunction(var) or inspect.ismethod(var)


		class PyQtCommunicator(QObject):
		"""Communicator class, that provides methods required for binding to communicate between ViewModel and View."""
		class PyQtObject(QObject):
		"""PyQt object class."""

		signal = pyqtSignal(object)


		class PyQtCommunicator(Communicator):
		"""Communicator class, that provides methods required for binding to communicate between ViewModel and View."""

		def __init__(
		self,
		viewmodel_linked_object: Any = None,
		@@ -43,6 +48,7 @@ class PyQtCommunicator(QObject):
		callback_after_update: Any = None,
		) -> None:
		super().__init__()
		self.pyqtobject = PyQtObject()
		self.viewmodel_linked_object = viewmodel_linked_object
		self.linked_object_attributes = linked_object_attributes
		self.callback_after_update = callback_after_update
		@@ -81,23 +87,27 @@ class PyQtCommunicator(QObject):
		if updated and self.callback_after_update:
		self.callback_after_update({"updated": updates, "errored": errors, "error": error})

		def connect(self, name: str, callback: Callable) -> Any:
		@override
		def connect(self, name: str, connector: Any) -> ConnectCallbackType:
		# connect should be called from the View side to connect a
		# GUI element (via a function to change GUI element that is passed to the connect call)
		# and a linked_object (passed during bind creation from ViewModel side)
		if name in bindings_map:
		raise Exception(f"cannot connect to binding {name}: already connected")
		if not is_callable(connector):
		raise ValueError("connector should be a callable type")

		check_binding(self.viewmodel_linked_object, name)
		bindings_map[name] = self
		self.prefix = name
		self.signal.connect(callback)
		self.pyqtobject.signal.connect(connector)
		if self.viewmodel_linked_object:
		return self._update_viewmodel_callback
		else:
		return None

		@override
		def update_in_view(self, value: Any) -> Any:
		"""Update a View (GUI) when called by a ViewModel."""
		return self.signal.emit(value)
		return self.pyqtobject.signal.emit(value)


		class PyQtBinding(BindingInterface):

src/nova/mvvm/trame_binding/binding.py

+3 −3

Original line number	Diff line number	Diff line
		@@ -10,7 +10,7 @@ from trame_server.state import State
		from typing_extensions import override

		from .._internal.pydantic_utils import get_errored_fields_from_validation_error, get_updated_fields
		from .._internal.utils import normalize_field_name, rget_list_of_fields, rgetattr, rsetattr
		from .._internal.utils import check_binding, normalize_field_name, rget_list_of_fields, rgetattr, rsetattr
		from ..bindings_map import bindings_map
		from ..interface import (
		BindingInterface,
		@@ -72,12 +72,12 @@ class TrameCommunicator(Communicator):
		else:
		connector = str(connector) if connector else None
		if connector:
		if connector in bindings_map:
		raise ValueError(f"cannot connect to binding {connector}: already connected")
		check_binding(self.viewmodel_linked_object, connector)
		bindings_map[connector] = self
		self.connection = StateConnection(self, connector)
		return self.connection.get_callback()

		@override
		def update_in_view(self, value: Any) -> None:
		self.connection.update_in_view(value)

tests/test_pyqt_bindings.py

+34 −5

Original line number	Diff line number	Diff line
		@@ -5,6 +5,7 @@ from typing import Any, Dict, List
		import pytest
		from PyQt6.QtWidgets import QLabel, QLineEdit, QMainWindow, QVBoxLayout, QWidget
		from pytestqt.qtbot import QtBot
		from typing_extensions import Generator

		from nova.mvvm import bindings_map
		from nova.mvvm.pydantic_utils import get_field_info
		@@ -14,6 +15,12 @@ from nova.mvvm.pyqt_binding.binding import PyQtCommunicator
		from .model import User


		@pytest.fixture(scope="function") # Default scope
		def function_scoped_fixture() -> Generator[str, None]:
		yield "function"
		bindings_map.clear()


		class MainWindow(QMainWindow):
		"""Test application class."""

		@@ -27,8 +34,7 @@ class MainWindow(QMainWindow):
		self.username_edit_box.setText(config.username)

		def process_config_change(self, key: str, value: Any) -> None:
		print(key, value)
		self.callback_config_object(key, value)
		self.callback_config_object(key, value) # type: ignore

		def get_description(self, field: str, default: str = "") -> str:
		try:
		@@ -50,7 +56,7 @@ class MainWindow(QMainWindow):
		self.setCentralWidget(container)


		def test_binding_model_to_pyqt(qtbot: QtBot) -> None:
		def test_binding_model_to_pyqt(qtbot: QtBot, function_scoped_fixture: str) -> None:
		# Creates pyqt binding for a Pydantic object, updates model and validates that the PyQt element was updated.

		test_object = User()
		@@ -85,7 +91,9 @@ test_cases: List[Dict[str, Any]] = [
		[(case["input"], case["result"]) for case in test_cases],
		ids=[case["test_name"] for case in test_cases],
		)
		def test_binding_pyqt_to_model(qtbot: QtBot, input: str, expected_result: Dict[str, Any]) -> None:
		def test_binding_pyqt_to_model(
		qtbot: QtBot, input: str, expected_result: Dict[str, Any], function_scoped_fixture: str
		) -> None:
		# Creates pyqt binding for a Pydantic object, updates user interface state and validates that the model was updated
		# or validation error occurred.
		after_update_results = {}
		@@ -105,4 +113,25 @@ def test_binding_pyqt_to_model(qtbot: QtBot, input: str, expected_result: Dict[s
		else:
		assert "username" in after_update_results["updated"]
		assert test_object.username == expected_result["value"]
		bindings_map.clear()


		def test_pyqt_binding_same_name(function_scoped_fixture: str) -> None:
		# Creates pyqt binding for with same name, expect error
		test_object = User()
		test_object2 = User()

		binding = PyQtBinding().new_bind(test_object)
		binding2 = PyQtBinding().new_bind(test_object2)
		binding.connect("test_object", lambda: print("hello"))
		with pytest.raises(ValueError):
		binding2.connect("test_object", lambda: print("hello"))


		def test_binding_same_object(function_scoped_fixture: str) -> None:
		# Creates pyqt binding for the same Pydantic object twice, expect error
		test_object = User()

		binding = PyQtBinding().new_bind(test_object)
		binding.connect("test_object", lambda: print("hello"))
		with pytest.raises(ValueError):
		binding.connect("test_object1", lambda: print("hello"))