Lightweight event delegation
This is a fork of the popular but abandoned delegate
with some improvements:
- modern: ES2022, TypeScript, Edge 16+ (it uses
WeakMap
andElement.closest()
) - idempotent: identical listeners aren't added multiple times, just like the native
addEventListener
- debugged (2d54c11, c6bb88c)
- supports
AbortSignal
npm install delegate-it
// This module is only offered as a ES Module
import delegate from 'delegate-it';
delegate('.btn', 'click', event => {
console.log(event.delegateTarget);
});
delegate('.btn', 'click', event => {
console.log(event.delegateTarget);
}, {
capture: true
});
Use this option if you don't want to have a global listener attached on html
, it improves performance:
delegate('.btn', 'click', event => {
console.log(event.delegateTarget);
}, {
base: document.querySelector('main')
});
const controller = new AbortController();
delegate('.btn', 'click', event => {
console.log(event.delegateTarget);
}, {
signal: controller.signal,
});
controller.abort();
delegate('.btn', 'click', event => {
console.log('This will only be called once');
}, {
once: true
});
import {oneEvent} from 'delegate-it';
await oneEvent('.btn', 'click');
console.log('The body was clicked');
If you're using TypeScript and have event types that are custom, you can override the global GlobalEventHandlersEventMap
interface via declaration merging. e.g. say you have a types/globals.d.ts
file, you can add the following.
interface GlobalEventHandlersEventMap {
'details:toggle': UIEvent;
}
In the file that imports EventType
, you will now be able to set the event type to 'details:toggled'
.
import {EventType} from 'delegate-it';
const someEventType1: EventType = 'details:toggled'; // all good
const someEventType2: EventType = 'click'; // all good
const someEventType3: EventType = 'some-invalid-event-type'; // no good
- select-dom - Lightweight
querySelector
/All
wrapper that outputs an Array. - doma - Parse an HTML string into
DocumentFragment
or oneElement
, in a few bytes. - Refined GitHub - Uses this module.