Race event-emitter events, resolves the first to occur. Promise-based ee-first
npm install first-eventjs
npm install --save first-event
`Usage
#### Error Example
js
var first = require('first-event')
var ee = new EventEmitter()first(ee, ['error', 'foo', 'bar'])
.catch(function (err) {
// error from emit 'error' gets sent here
console.log(err) // [ Error: 'boom' ]
})
ee.emit('error', new Error('boom'))
// below does nothing, bc it happenned second
ee.emit('foo', 1)
`
#### Event Example
js
var first = require('first-event')
var ee = new EventEmitter()first(ee, ['error', 'foo', 'bar'])
.then(function (firstEvent) {
console.log(firstEvent.ee) // [ EventEmitter: ... ]
console.log(firstEvent.event) // 'foo'
console.log(firstEvent.args) // [ 'one', 'two', 'three' ]
})
ee.emit('foo', 'one', 'two', 'three')
// below does nothing, bc it happenned second
ee.emit('bar', 1)
`
#### Race Events from different EventEmitters
js
var first = require('first-event')
var ee = new EventEmitter()
var ee2 = new EventEmitter()Promise.race(
first(ee, ['error', 'foo', 'bar'])
first(ee2, ['error', 'foo', 'bar'])
).then(function (firstEvent) {
console.log(firstEvent.ee) // [ EventEmitter: ... ] === ee2
console.log(firstEvent.event) // 'foo'
console.log(firstEvent.args) // [ 'one', 'two', 'three' ]
})
ee2.emit('foo', 'one', 'two', 'three')
// below does nothing, bc it happenned second
ee.emit('bar', 1)
`
$3
js
var first = require('first-event')
var ee = new EventEmitter()
var eventPromise = first(ee, ['error', 'foo', 'bar'])eventPromise
.then(function (data) {
// never happens, bc event handlers were cancelled below
}).catch(function () {
// never happens, bc event handlers were cancelled below
})
// cancel and cleanup event handlers
eventPromise.cancel()
// below will do nothing, bc the event handlers were removed
ee.emit('foo', 1)
``