Historic hooks

A spec marked historic remembers its calls and replays them to plugins registered after the call happened. This suits one-off events - startup, configuration loaded - where some plugins may load late (for example via entry-point discovery that runs after the event already fired).

@extension_point(historic=True)
def kitchen_opened(name: str) -> None:
    """Announce the kitchen opened; late plugins still hear it."""

Calling a historic hook

A historic hook is not called like a normal one. Use call_historic, passing the keyword arguments as a dict and an optional callback for each result:

pm.caller(Specs.kitchen_opened).call_historic(
    kwargs={"name": "Main Street"},
    result_callback=log.append,
)

Calling a historic hook with the plain pm.caller(Specs.kitchen_opened)(...) form raises a TypeError, and vice versa - the two calling styles are kept distinct on purpose.

Replay to late plugins

Any plugin registered after the call immediately receives it:

pm.register(early, name="early")
pm.caller(Specs.kitchen_opened).call_historic(kwargs={"name": "Main Street"})
pm.register(late, name="late")     # 'late' still runs kitchen_opened("Main Street")

The result_callback fires once per implementation - for plugins present at call time, and again for each late plugin as it is registered.

Constraints

• A historic hook cannot be firstresult (replay has no single "winner"); the manager rejects that combination at add_extension_points time.

Run it

make run DEMO=historic

Early plugin greeting: Early staff ready at Main Street
Late plugin greeting:  Late staff caught up at Main Street (registered after the event)
result_callback saw:  ['Early staff ready at Main Street', 'Late staff caught up at Main Street']

The app lifecycle example uses a historic configure hook so a late-loading cache plugin still receives the application settings.