main-event


> Typed event emitters

About

Adds types to the EventTarget class.

Hopefully this won't be necessary
forever:

-
-
-
-
-
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- etc

In addition to types, a safeDispatchEvent method is available which
prevents dispatching events that aren't in the event map, and a
listenerCount method which reports the number of listeners that are
currently registered for a given event.

Example

``ts
import { TypedEventEmitter } from 'main-event'
import type { TypedEventTarget } from 'main-event'

interface EventTypes {
'test': CustomEvent
}

const target = new TypedEventEmitter()

// it's a regular EventTarget
console.info(target instanceof EventTarget) // true

// register listeners normally
target.addEventListener('test', (evt) => {
// evt is CustomEvent
})

// @ts-expect-error 'derp' is not in the event map
target.addEventListener('derp', () => {})

// use normal dispatchEvent method
target.dispatchEvent(new CustomEvent('test', {
detail: 'hello'
}))

// use type safe dispatch method
target.safeDispatchEvent('test', {
detail: 'world'
})

// report listener count
console.info(target.listenerCount('test')) // 0

// event emitters can be used purely as interfaces too
function acceptTarget (target: TypedEventTarget) {
// ...
}
`

Install

`console
$ npm i main-event
`

Browser
``

License

Licensed under either of

- Apache 2.0, (LICENSE-APACHE / )
- MIT (LICENSE-MIT / )

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.