API

event.on(name, handler)

Listens permanently for an event.

1 event.on('page:ready', (data) => { ... });

Parameter	Type	Description
`name`	`string`	Event name — exact match, wildcards (`page:*`) are not supported
`handler`	`function`	Callback, receives the payload

event.once(name, handler)

Listens once – the handler is automatically removed after the first call.

1 event.once('project:ready', (data) => { ... });

event.off(name, handler)

Removes a specific listener.

1 const handler = (data) => { ... };
2 event.on('page:ready', handler);
3 event.off('page:ready', handler);

The same handler reference must be passed – anonymous functions cannot be removed.

event.emit(name, payload?)

Fires an event. All active listeners are called synchronously.

1 event.emit('page:ready', { lang: 'en', route: '/privacy/' });
2 event.emit('app:stopping');  // payload optional

event.register(name, meta)

Optionally documents an event with metadata. Not required.

1 event.register('page:ready', {
2     description: 'Page rendered, i18n can take over',
3     emittedBy:   '@xpulse/project',
4     payload:     '{ lang: string, route: string }',
5 });

Parameter	Type	Description
`name`	`string`	Event name
`meta.description`	`string`	What the event means
`meta.emittedBy`	`string`	Which package emits the event
`meta.payload`	`string`	Payload structure as string

event.list()

Returns all registered events with metadata.

1 event.list();
2 // → [
3 //     { name: 'page:ready', description: '...', emittedBy: '...', listeners: 2 },
4 //   ]

event.listeners(name)

Returns all active listener functions for an event.

1 event.listeners('page:ready');
2 // → [ [Function: handler1], [Function: handler2] ]

event.listenerCount(name)

Returns the number of active listeners for an event.

1 event.listenerCount('page:ready');
2 // → 2

1	const handler = (data) => { ... };
2	event.on('page:ready', handler);
3	event.off('page:ready', handler);

1	event.emit('page:ready', { lang: 'en', route: '/privacy/' });
2	event.emit('app:stopping'); // payload optional

1	event.register('page:ready', {
2	description: 'Page rendered, i18n can take over',
3	emittedBy: '@xpulse/project',
4	payload: '{ lang: string, route: string }',
5	});

1	event.list();
2	// → [
3	// { name: 'page:ready', description: '...', emittedBy: '...', listeners: 2 },
4	// ]

1	event.listeners('page:ready');
2	// → [ [Function: handler1], [Function: handler2] ]