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createEventEmitter
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function createEventEmitter() { | |
const events = {} | |
return { | |
on: (name, listener) => { | |
if (typeof name !== 'string') { | |
throw new Error(`Not valid name ${name}:${typeof name}`) | |
} | |
if (typeof listener !== 'function') { | |
throw new Error(`Not valid listener ${name} ${typeof listener}`) | |
} | |
const listeners = events.hasOwnProperty(name) | |
? events[name] | |
: (events[name] = []) | |
listeners.push(listener) | |
}, | |
emit: (name, ...params) => { | |
const listeners = events[name] || [] | |
return listeners.map((listener) => { | |
return listener(...params) | |
}) | |
}, | |
remove: (name, listener) => { | |
const index = events[name].indexOf(listener) | |
events[name].splice(index, 1) | |
} | |
} | |
} | |
const emitter = createEventEmitter() | |
function listener(a, b) { | |
console.log(a, b) | |
} | |
emitter.on('myevent', listener) | |
emitter.emit('myevent', 1, 2) | |
emitter.remove('myevent', listener) | |
emitter.emit('myevent', 1, 2) |
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