slct

A native DOM selection engine with cache built in.

584 B. :zap:

Motivation.

Usage

Using npm:

$ npm install --save slct

The UMD build is also available on unpkg:

<script src="https://unpkg.com/slct/dist/slct.min.js"></script>

API

slct(query, invalidate)

query

A normal query string with an identifier.

The substring after the identifier will be passed into the native DOM methods.

Type: String

// Supported Identifiers
// '.' =     getElementsByClassName
// '#' =     getElementById
// '%' =     getElementsByTagName
// '@' =     getElementsByName
// '?' =     querySelector
// '*' =     querySelectorAll

// Examples:
import $ from 'slct';

$('.links')    // document.getElementsByClassName('.links');
$('#logo')     // document.getElementById('logo');
$('%li')       // document.getElementsByTagName('li');
$('@random')   // document.getElementsByName('random');
$('?div')      // document.querySelector('div');
$('*.links')   // document.querySelectorAll('.links');

invalidate

To invalidate a selector and re-cache it.

Type: Boolean

Default: false

Motivation

Often, we have to write code that looks like this:

/**
 * 1.
 * Here, we are caching the selector for better performance.
 * This prevents any additional DOM lookup when the selector
 * is needed again.
 *
 * Also, notice the very verbose DOM API's. Who wants to write
 * `document.querySelectorAll` over and over again?
 */
const links = document.querySelectorAll('.links');
const logo = document.getElementById('logo');
const li = document.getElementsByTagName('li');
const name = document.getElementsByTagName('random');
const blue = document.getElementsByClassName('blue');

/**
 * 2.
 * Since NodeList is not Array-like, we can't call `forEach` directly,
 * and this results in the following code.
 */
[].forEach.call(links, (link) => {
    link.addEventListener('click', () => {
        link.style.color = 'red';
    });
});

What if we can write code that looks like this ?

/**
 * slct automatically caches the selector and convert NodeList
 * into Array-like, thus resulting in less boilerplate code.
 */
import $ from 'slct';

$('*.links').forEach((link) => {
    link.addEventListener('click', () => {
        link.style.color = 'red';
    });
});


/**
 * To invalidate the selector and re-cache it.
 */
$('*.links', true);

/**
 * Also, it comes with identifiers so that you don't have to write
 * those verbose DOM API's.
 * Read the API section for more info.
 */
 $('@random')   // document.getElementsByName('random');
 $('?div')      // document.querySelector('div');

License

MIT © Jonathan Chan