feat(anywidget): Drop ipywidgets dependency

anywidget/_descriptor.py

@@ -304,6 +304,7 @@ def __init__(
         self._extra_state = (extra_state or {}).copy()
         self._extra_state.setdefault(_ANYWIDGET_ID_KEY, _anywidget_id(obj))
         self._no_view = no_view
+        self._callbacks = []
 
         try:
             self._obj: Callable[[], object] = weakref.ref(obj, self._on_obj_deleted)
@@ -397,29 +398,39 @@ def _handle_msg(self, msg: CommMessage) -> None:
         elif data["method"] == "request_state":
             self.send_state()
 
-        # elif method == "custom":  # noqa: ERA001
-        # Handle a custom msg from the front-end.
-        # if "content" in data:
-        #     self._handle_custom_msg(data["content"], msg["buffers"])  # noqa: ERA001
-        else:  # pragma: no cover
+        elif data["method"] == "custom":
+            if "content" in data:
+                self._handle_custom_msg(data["content"], msg["buffers"])
+
+        else:
             err_msg = (
                 f"Unrecognized method: {data['method']}.  Please report this at "
                 "https://github.com/manzt/anywidget/issues"
             )
             raise ValueError(err_msg)
 
-    # def _handle_custom_msg(self, content: object, buffers: list[memoryview]):
-    #     # TODO(manzt): handle custom callbacks  # noqa: TD003
-    #     # https://github.com/jupyter-widgets/ipywidgets/blob/6547f840edc1884c75e60386ec7fb873ba13f21c/python/ipywidgets/ipywidgets/widgets/widget.py#L662
-    #     ...
+    def _handle_custom_msg(self, content: Any, buffers: list[memoryview]):
+        # https://github.com/jupyter-widgets/ipywidgets/blob/b78de43e12ff26e4aa16e6e4c6844a7c82a8ee1c/python/ipywidgets/ipywidgets/widgets/widget.py#L186
+        for callback in self._callbacks:
+            try:
+                callback(content, buffers)
+            except Exception:
+                warnings.warn(
+                    "Error in custom message callback",
+                    stacklevel=2,
+                )
 
     def __call__(self, **kwargs: Sequence[str]) -> tuple[dict, dict] | None:  # noqa: ARG002
         """Called when _repr_mimebundle_ is called on the python object."""
         # NOTE: this could conceivably be a method on a Comm subclass
         # (i.e. the comm knows how to represent itself as a mimebundle)
         if self._no_view:
             return None
-        return repr_mimebundle(model_id=self._comm.comm_id, repr_text=repr(self._obj()))
+
+        repr_text = repr(self._obj())
+        if len(repr_text) > 110:
+            repr_text = repr_text[:110] + "…"
+        return repr_mimebundle(model_id=self._comm.comm_id, repr_text=repr_text)
 
     def sync_object_with_view(
         self,
@@ -485,6 +496,18 @@ def unsync_object_with_view(self) -> None:
             with contextlib.suppress(Exception):
                 self._disconnectors.pop()()
 
+    def register_callback(
+        self, callback: Callable[[Any, Any, list[bytes]], None]
+    ) -> None:
+        self._callbacks.append(callback)
+
+    def send(
+        self, content: str | list | dict, buffers: list[memoryview] | None = None
+    ) -> None:
+        """Send a custom message to the front-end view."""
+        data = {"method": "custom", "content": content}
+        self._comm.send(data=data, buffers=buffers)  # type: ignore[arg-type]
+
 
 # ------------- Helper function --------------
 

anywidget/_protocols.py

@@ -66,9 +66,9 @@ class AnywidgetProtocol(Protocol):
 class WidgetBase(Protocol):
     """Widget subclasses with a custom message reducer."""
 
-    def send(self, msg: str | dict | list, buffers: list[bytes]) -> None: ...
+    def send(self, msg: Any, buffers: list[memoryview] | list[bytes] | None) -> None: ...
 
     def on_msg(
         self,
-        callback: Callable[[Any, str | list | dict, list[bytes]], None],
+        callback: Callable[[Any, str | list | dict, list[bytes] | list[memoryview]], None],
     ) -> None: ...

anywidget/_version.py

@@ -1,15 +1,6 @@
-try:
-    from importlib.metadata import PackageNotFoundError, version
-except ImportError:
-    from importlib_metadata import (  # type: ignore[import-not-found, no-redef]
-        PackageNotFoundError,
-        version,
-    )
+import importlib.metadata
 
-try:
-    __version__ = version("anywidget")
-except PackageNotFoundError:
-    __version__ = "uninstalled"
+__version__ = importlib.metadata.version("anywidget")
 
 
 def get_semver_version(version: str) -> str:

anywidget/experimental.py

@@ -113,8 +113,8 @@ def _decorator(cls: T) -> T:
 _ANYWIDGET_COMMANDS = "_anywidget_commands"
 
 _AnyWidgetCommand = typing.Callable[
-    [object, object, typing.List[bytes]],
-    typing.Tuple[object, typing.List[bytes]],
+    [object, object, list[bytes] | list[memoryview]],
+    tuple[object, list[bytes] | list[memoryview]],
 ]
 
 
@@ -160,14 +160,14 @@ def _register_anywidget_commands(widget: WidgetBase) -> None:
 
     def handle_anywidget_command(
         self: WidgetBase,
-        msg: str | list | dict,
-        buffers: list[bytes],
+        msg: typing.Any,
+        buffers: list[bytes] | list[memoryview],
     ) -> None:
         if not isinstance(msg, dict) or msg.get("kind") != "anywidget-command":
             return
         cmd = cmds[msg["name"]]
-        response, buffers = cmd(widget, msg["msg"], buffers)
-        self.send(
+        response, buffers = cmd(widget, msg["msg"], buffers or [])
+        widget.send(
             {
                 "id": msg["id"],
                 "kind": "anywidget-command-response",

anywidget/widget.py

@@ -2,81 +2,42 @@
 
 from __future__ import annotations
 
-import ipywidgets
-import traitlets.traitlets as t
+from typing import Any, Callable
 
-from ._file_contents import FileContents, VirtualFileContents
-from ._util import (
-    _ANYWIDGET_ID_KEY,
-    _CSS_KEY,
-    _DEFAULT_ESM,
-    _ESM_KEY,
-    enable_custom_widget_manager_once,
-    in_colab,
-    repr_mimebundle,
-    try_file_contents,
-)
-from ._version import _ANYWIDGET_SEMVER_VERSION
-from .experimental import _collect_anywidget_commands, _register_anywidget_commands
-
-_PLAIN_TEXT_MAX_LEN = 110
-
-
-class AnyWidget(ipywidgets.DOMWidget):  # type: ignore [misc]
-    """Main AnyWidget base class."""
+import traitlets
 
-    _model_name = t.Unicode("AnyModel").tag(sync=True)
-    _model_module = t.Unicode("anywidget").tag(sync=True)
-    _model_module_version = t.Unicode(_ANYWIDGET_SEMVER_VERSION).tag(sync=True)
 
-    _view_name = t.Unicode("AnyView").tag(sync=True)
-    _view_module = t.Unicode("anywidget").tag(sync=True)
-    _view_module_version = t.Unicode(_ANYWIDGET_SEMVER_VERSION).tag(sync=True)
-
-    def __init__(self, *args: object, **kwargs: object) -> None:
-        if in_colab():
-            enable_custom_widget_manager_once()
+from ._descriptor import MimeBundleDescriptor
+from ._util import _CSS_KEY, _ESM_KEY
+from .experimental import _collect_anywidget_commands, _register_anywidget_commands
 
-        anywidget_traits = {}
-        for key in (_ESM_KEY, _CSS_KEY):
-            if hasattr(self, key) and not self.has_trait(key):
-                value = getattr(self, key)
-                anywidget_traits[key] = t.Unicode(str(value)).tag(sync=True)
-                if isinstance(value, (VirtualFileContents, FileContents)):
-                    value.changed.connect(
-                        lambda new_contents, key=key: setattr(self, key, new_contents),
-                    )
 
-        # show default _esm if not defined
-        if not hasattr(self, _ESM_KEY):
-            anywidget_traits[_ESM_KEY] = t.Unicode(_DEFAULT_ESM).tag(sync=True)
+class AnyWidget(traitlets.HasTraits):  # type: ignore [misc]
+    """Main AnyWidget base class."""
 
-        # TODO(manzt): a better way to uniquely identify this subclasses?  # noqa: TD003
-        # We use the fully-qualified name to get an id which we
-        # can use to update CSS if necessary.
-        anywidget_traits[_ANYWIDGET_ID_KEY] = t.Unicode(
-            f"{self.__class__.__module__}.{self.__class__.__name__}",
-        ).tag(sync=True)
+    _repr_mimebundle_: MimeBundleDescriptor
 
-        self.add_traits(**anywidget_traits)
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
         super().__init__(*args, **kwargs)
         _register_anywidget_commands(self)
+        # Access _repr_mimebundle_ descriptor to trigger comm initialization
+        self._repr_mimebundle_  # noqa: B018
 
     def __init_subclass__(cls, **kwargs: dict) -> None:
-        """Coerces _esm and _css to FileContents if they are files."""
+        """Create the _repr_mimebundle_ descriptor and register anywidget commands."""
         super().__init_subclass__(**kwargs)
-        for key in (_ESM_KEY, _CSS_KEY) & cls.__dict__.keys():
-            # TODO(manzt): Upgrate to := when we drop Python 3.7
-            # https://github.com/manzt/anywidget/pull/167
-            file_contents = try_file_contents(getattr(cls, key))
-            if file_contents:
-                setattr(cls, key, file_contents)
+        extra_state = {
+            key: getattr(cls, key) for key in (_ESM_KEY, _CSS_KEY) & cls.__dict__.keys()
+        }
+        cls._repr_mimebundle_ = MimeBundleDescriptor(**extra_state)
         _collect_anywidget_commands(cls)
 
-    def _repr_mimebundle_(self, **kwargs: dict) -> tuple[dict, dict] | None:  # noqa: ARG002
-        plaintext = repr(self)
-        if len(plaintext) > _PLAIN_TEXT_MAX_LEN:
-            plaintext = plaintext[:110] + "…"
-        if self._view_name is None:
-            return None  # type: ignore[unreachable]
-        return repr_mimebundle(model_id=self.model_id, repr_text=plaintext)
+    def send(self, msg: Any, buffers: list[memoryview] | None = None) -> None:
+        """Send a message to the frontend."""
+        self._repr_mimebundle_.send(content=msg, buffers=buffers)
+
+    def on_msg(
+        self, callback: Callable[[Any, str | list | dict, list[bytes]], None]
+    ) -> None:
+        """Register a message handler."""
+        self._repr_mimebundle_.register_callback(callback)

pyproject.toml

@@ -12,11 +12,6 @@ license = { text = "MIT" }
 dynamic = ["version"]
 readme = "README.md"
 requires-python = ">=3.8"
-dependencies =  [
-    "ipywidgets>=7.6.0",
-    "typing-extensions>=4.2.0",
-    "psygnal>=0.8.1",
-]
 classifiers = [
     "Framework :: Jupyter",
     "Framework :: Jupyter :: JupyterLab",
@@ -27,22 +22,29 @@ classifiers = [
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
 ]
-
-[project.urls]
-homepage = "https://github.com/manzt/anywidget"
+dependencies =  [
+    "comm>=0.1.4",
+    "psygnal>=0.8.1",
+    "traitlets>=4.3.1",
+    "jupyterlab-widgets~=3.0.12", # Installs widgets extension for JupyterLab
+    "widgetsnbextension~=4.0.12", # Installs widgets extension for classic notebooks
+]
 
 [project.optional-dependencies]
 dev = ["watchfiles>=0.18.0"]
 
+[project.urls]
+homepage = "https://github.com/manzt/anywidget"
+
 [tool.uv]
 dev-dependencies = [
-    "comm>=0.1.4",
     "jupyterlab>=4.2.4",
     "msgspec>=0.18.6",
     "mypy>=1.11.1",
     "pydantic>=2.5.3",
     "pytest>=7.4.4",
     "ruff>=0.6.1",
+    "typing-extensions>=4.12.2",
     "watchfiles>=0.23.0",
 ]
 
@@ -153,5 +155,5 @@ disallow_untyped_calls = false
 
 [[tool.mypy.overrides]]
 # this might be missing in pre-commit, but they aren't typed anyway
-module = ["ipywidgets", "traitlets.*", "comm", "IPython.*"]
+module = ["traitlets.*", "comm", "IPython.*"]
 ignore_missing_imports = true