Eventable

Eventable is the event-system mixin factory of maptalks. It gives a host class full on/off/once/fire event capabilities. It is not instantiated on its own; instead it is merged into other classes (such as Map, GroupLayer) via Class.include(Eventable) or a similar mechanism, so those classes can listen for, dispatch, and manage events.

import { Eventable } from "maptalks";

class MyThing extends Eventable(Class) { /* ... */ }

const thing = new MyThing();
thing.on("click", () => console.log("clicked"));
thing.fire("click");
thing.off("click", () => console.log("clicked"));

Constructor

Mixin factory — no independent constructor. The host class gains event capability automatically after construction.

options

No independent configuration options. Event behavior is governed by the host class's own options.

Methods

• on(events, handler, context?) — Register a listener for the given event(s). events may be a single event name or space-separated names; handler is the callback; context optionally sets the this for the callback.
• addEventListener(events, handler, context?) — Alias of on.
• off(events, handler, context?) — Remove an event listener, matched by event name and handler; if handler is omitted, no listeners are removed.
• removeEventListener(events, handler, context?) — Alias of off.
• once(events, handler, context?) — Register a listener that fires only once, then removes itself.
• listens(eventType, handler?, context?) — Whether a listener exists for the given event; with handler, checks whether that exact callback is listened to.
• getListeningEvents() — Return all registered events and their listeners of the instance.
• copyEventListeners(target) — Copy this instance's listeners onto the target object.
• fire(eventType, param?) — Dispatch (fire) an event of the given type, passing param as the event data to listeners.

Static Methods

None.

Events

Concrete events are fired by the host class. The event types raised by fire() are what listeners receive.