js-debounce-throttle

Debounce and throttle functions to enhance the website performance by limiting/reducing the number of times the handler function is being executed due to user events. User events can be engagements like clicks, scroll, resize, text box inputs, mouse events etc.

Install

npm install js-debounce-throttle --save

Usage

Debouncing

// Demo: Debouncing
'use strict';
import { debounce } from "js-debounce-throttle";

const functionToExecute = (value) => {
  // Print the value to Console 
  console.log('Value:', value);
}

/**
 * Using debounce() function
 * Param 1: Callback function to execute for debouncing behaviour eg. functionToExecute()
 * Parram 2: Time in milliseconds or debouncing interval eg. 500
 */
const debounceFunction = debounce(functionToExecute, 500);

/**
 * A search text box with element id 'searchTextBox'
 * listens for 'keyup' event to execute debouncing
 */
const searchTextBoxInput = document.getElementById('searchTextBox');
searchTextBoxInput.addEventListener("keyup", event => {
  debounceFunction(event.target.value);
});

Throttling

// Demo: Throttling
'use strict';
import { throttle } from "js-debounce-throttle";

const functionToExecute = (value) => {
  // Print the value to Console 
  console.log('Value:', value);
}

/**
 * Using throttle() function
 * Param 1: Callback function to execute for throttling behaviour eg. functionToExecute()
 * Parram 2: Time in milliseconds or throttling interval eg. 300
 */
const throttleFunction = throttle(functionToExecute, 300);

/**
 * A search text box with element id 'searchTextBox'
 * listens for 'keyup' event to execute throttling
 */
const searchTextBoxInput = document.getElementById('searchTextBox');
searchTextBoxInput.addEventListener("keyup", event => {
  throttleFunction(event.target.value);
});

API

debounce(callback, delay): Function

debounce function itself returns a Function which is the debounce execution of the callback function.

Debouncing can be applied in implementing suggestive text, where we wait for the user to stop typing for a few seconds before suggesting the text. thus, on every keystroke, we wait for some seconds before giving out suggestions. Another application of debouncing is in content-loading webpages like Facebook and Twitter where the user keeps on scrolling. In these scenarios, if the scroll event is fired too frequently, there might be a performance impact, as it contains lots of videos and images. Thus the scroll event must make use of debouncing.

throttle(callback, delay): Function

throttle function itself returns a Function which is the throttle execution of the callback function.

It prevent frequent calling of the function. It makes the website faster and controls the rate at which a particular function is called.

Parameter | Type | Description ------------ | ------------- | ------------- callback | Function | Function to be executed after the delay. The this context and all arguments are passed through, as-is, to callback when the throttled/debounced function is executed. delay | Number | Time delay expressed in milliseconds to debounce/throttle the function execution.

Browser Support

All modern browsers and IE10+.

License

MIT