Create a debounced version of a promise returning function
npm install debounce-promise
Create a debounced version of a promise returning function
npm i -S debounce-promise
``js
var debounce = require('debounce-promise')
function expensiveOperation(value) {
return Promise.resolve(value)
}
var saveCycles = debounce(expensiveOperation, 100);
[1, 2, 3, 4].forEach(num => {
return saveCycles('call no #' + num).then(value => {
console.log(value)
})
})
// Will only call expensiveOperation once with argument 4 and print:`
//=> call no #4
//=> call no #4
//=> call no #4
//=> call no #4
`js
var debounce = require('debounce-promise')
function expensiveOperation(value) {
return Promise.resolve(value)
}
var saveCycles = debounce(expensiveOperation, 100, {leading: true});
[1, 2, 3, 4].forEach(num => {
return saveCycles('call no #' + num).then(value => {
console.log(value)
})
})
//=> call no #1
//=> call no #4
//=> call no #4
//=> call no #4
`
`js
var debounce = require('debounce-promise')
function squareValues (argTuples) {
return Promise.all(argTuples.map(args => args[0] * args[0]))
}
var square = debounce(squareValues, 100, {accumulate: true});
[1, 2, 3, 4].forEach(num => {
return square(num).then(value => {
console.log(value)
})
})
//=> 1
//=> 4
//=> 9
//=> 16
`
Returns a debounced version of
that delays invoking until after wait milliseconds.Set
leading: true if you
want to call func and return its promise immediately.Set
accumulate: true if you want the debounced function to be called with an array of all the arguments received while waiting.Supports passing a function as the
wait parameter, which provides a way to lazily or dynamically define a wait timeout.
Example timeline illustration
`js
function refresh() {
return fetch('/my/api/something')
}
const debounced = debounce(refresh, 100)
`
time (ms) -> 0 --- 10 --- 50 --- 100 ---
-----------------------------------------------
debounced() | --- P(1) --- P(1) --- P(1) ---
refresh() | --------------------- P(1) ---
js
const debounced = debounce(refresh, 100, {leading: true})
`
time (ms) -> 0 --- 10 --- 50 --- 100 --- 110 ---
--------------------------------------------------------
debounced() | --- P(1) --- P(2) --- P(2) --- P(2) ---
refresh() | --- P(1) --------------------- P(2) ---