Pluggable UI backend for guidata dialogs

By default, guidata.dataset.DataSet and friends open Qt dialogs to edit/view their contents. This module exposes a tiny registry that lets applications register alternate handlers (for example, a browser/React backend running inside Pyodide) without modifying the Qt path used by existing applications.

Handler names (slots)

The following slot names are recognised:

  • "edit_dataset" — synchronous edition of a DataSet. Signature: handler(instance, *, parent, apply, wordwrap, size, object_name) -> int. Should return a Qt-like exit code (1 = accepted, 0 = rejected).

  • "view_dataset" — read-only display of a DataSet. Signature: handler(instance, *, parent, wordwrap, size) -> int.

  • "edit_dataset_group" — synchronous edition of a DataSetGroup. Signature: handler(instance, *, parent, apply, wordwrap, size, mode) -> int.

  • "edit_dataset_async" — asynchronous edition of a DataSet. Signature: handler(instance, *, parent, apply, wordwrap, size, object_name) -> Awaitable[int]. When unset, DataSet.edit_async() falls back to the synchronous handler.

Handlers are looked up at call time, so they may be registered after DataSet instances have been created.

When no handler is registered for a slot, the default Qt-based implementation is used. This keeps existing Qt applications behaving exactly as before.

Example

from guidata.dataset import backends

def my_edit_handler(instance, **kwargs):
    # Render the dataset in a custom UI; return 1 if accepted.
    ...

backends.set_handler("edit_dataset", my_edit_handler)
guidata.dataset.backends.clear_all_handlers() → None

Unregister every handler. Mostly useful for tests.

guidata.dataset.backends.clear_handler(name: str) → None

Unregister the handler for name (no-op if none registered).

guidata.dataset.backends.get_handler(name: str) → Callable[[...], Any] | None

Return the handler registered for name, or None.

guidata.dataset.backends.has_handler(name: str) → bool

Return True if a handler is registered for name.

guidata.dataset.backends.set_handler(name: str, handler: Callable[[...], Any]) → None

Register a handler for the given slot name.

Parameters:

  • name – Slot name (see module docstring for the list).

  • handler – Callable matching the signature documented for the slot.