Cara menggunakan javascript load css

Is it possible to import css stylesheets into a html page using Javascript? If so, how can it be done?

P.S the javascript will be hosted on my site, but I want users to be able to put in the <head> tag of their website, and it should be able to import a css file hosted on my server into the current web page. (both the css file and the javascript file will be hosted on my server).

asked Feb 22, 2009 at 13:48

1

Here's the "old school" way of doing it, which hopefully works across all browsers. In theory, you would use setAttribute unfortunately IE6 doesn't support it consistently.

var cssId = 'myCss';  // you could encode the css path itself to generate id..
if (!document.getElementById(cssId))
{
    var head  = document.getElementsByTagName('head')[0];
    var link  = document.createElement('link');
    link.id   = cssId;
    link.rel  = 'stylesheet';
    link.type = 'text/css';
    link.href = 'http://website.example/css/stylesheet.css';
    link.media = 'all';
    head.appendChild(link);
}

This example checks if the CSS was already added so it adds it only once.

Put that code into a JavaScript file, have the end-user simply include the JavaScript, and make sure the CSS path is absolute so it is loaded from your servers.

VanillaJS

Here is an example that uses plain JavaScript to inject a CSS link into the head element based on the filename portion of the URL:

<script type="text/javascript">
var file = location.pathname.split( "/" ).pop();

var link = document.createElement( "link" );
link.href = file.substr( 0, file.lastIndexOf( "." ) ) + ".css";
link.type = "text/css";
link.rel = "stylesheet";
link.media = "screen,print";

document.getElementsByTagName( "head" )[0].appendChild( link );
</script>

Insert the code just before the closing head tag and the CSS will be loaded before the page is rendered. Using an external JavaScript (.js) file will cause a Flash of unstyled content (FOUC) to appear.

answered Feb 23, 2009 at 9:25

7

If you use jquery:

$('head').append('<link rel="stylesheet" type="text/css" href="style.css">');

answered Oct 28, 2015 at 9:13

BoumTACBoumTAC

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1

I guess something like this script would do:

<script type="text/javascript" src="/js/styles.js"></script>

This JS file contains the following statement:

if (!document.getElementById) document.write('<link rel="stylesheet" type="text/css" href="/css/versions4.css">');

The address of the javascript and css would need to be absolute if they are to refer to your site.

Many CSS import techniques are discussed in this "Say no to CSS hacks with branching techniques" article.

But the "Using JavaScript to dynamically add Portlet CSS stylesheets" article mentions also the CreateStyleSheet possibility (proprietary method for IE):

<script type="text/javascript">
//<![CDATA[
if(document.createStyleSheet) {
  document.createStyleSheet('http://server/stylesheet.css');
}
else {
  var styles = "@import url(' http://server/stylesheet.css ');";
  var newSS=document.createElement('link');
  newSS.rel='stylesheet';
  newSS.href='data:text/css,'+escape(styles);
  document.getElementsByTagName("head")[0].appendChild(newSS);
}
//]]>

answered Feb 22, 2009 at 13:56

VonCVonC

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4

Element.insertAdjacentHTML has very good browser support, and can add a stylesheet in one line.

document.getElementsByTagName("head")[0].insertAdjacentHTML(
    "beforeend",
    "<link rel=\"stylesheet\" href=\"path/to/style.css\" />");

answered Jun 12, 2018 at 17:22

dangowansdangowans

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If you want to know (or wait) until the style itself has loaded this works:

// this will work in IE 10, 11 and Safari/Chrome/Firefox/Edge
// add ES6 poly-fill for the Promise, if needed (or rewrite to use a callback)

let fetchStyle = function(url) {
  return new Promise((resolve, reject) => {
    let link = document.createElement('link');
    link.type = 'text/css';
    link.rel = 'stylesheet';
    link.onload = function() { resolve(); console.log('style has loaded'); };
    link.href = url;

    let headScript = document.querySelector('script');
    headScript.parentNode.insertBefore(link, headScript);
  });
};

answered Dec 2, 2016 at 14:01

sandstromsandstrom

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2

Use this code:

var element = document.createElement("link");
element.setAttribute("rel", "stylesheet");
element.setAttribute("type", "text/css");
element.setAttribute("href", "external.css");
document.getElementsByTagName("head")[0].appendChild(element);

answered Sep 27, 2017 at 4:17

In a modern browser you can use promise like this. Create a loader function with a promise in it:

function LoadCSS( cssURL ) {

    // 'cssURL' is the stylesheet's URL, i.e. /css/styles.css

    return new Promise( function( resolve, reject ) {

        var link = document.createElement( 'link' );

        link.rel  = 'stylesheet';

        link.href = cssURL;

        document.head.appendChild( link );

        link.onload = function() { 

            resolve(); 

            console.log( 'CSS has loaded!' ); 
        };
    } );
}

Then obviously you want something done after the CSS has loaded. You can call the function that needs to run after CSS has loaded like this:

LoadCSS( 'css/styles.css' ).then( function() {

    console.log( 'Another function is triggered after CSS had been loaded.' );

    return DoAfterCSSHasLoaded();
} );

Useful links if you want to understand in-depth how it works:

Official docs on promises

Useful guide to promises

A great intro video on promises

answered Jul 5, 2018 at 3:41

Arthur TarasovArthur Tarasov

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0

I know this is a pretty old thread but here comes my 5 cents.

There is another way to do this depending on what your needs are.

I have a case where i want a css file to be active only a while. Like css switching. Activate the css and then after another event deativate it.

Instead of loading the css dynamically and then removing it you can add a Class/an id in front of all elements in the new css and then just switch that class/id of the base node of your css (like body tag).

You would with this solution have more css files initially loaded but you have a more dynamic way of switching css layouts.

answered Jan 25, 2012 at 8:04

JohanSellbergJohanSellberg

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Have you ever heard of Promises? They work on all modern browsers and are relatively simple to use. Have a look at this simple method to inject css to the html head:

function loadStyle(src) {
    return new Promise(function (resolve, reject) {
        let link = document.createElement('link');
        link.href = src;
        link.rel = 'stylesheet';

        link.onload = () => resolve(link);
        link.onerror = () => reject(new Error(`Style load error for ${src}`));

        document.head.append(link);
    });
}

You can implement it as follows:

window.onload = function () {
    loadStyle("https://fonts.googleapis.com/css2?family=Raleway&display=swap")
        .then(() => loadStyle("css/style.css"))
        .then(() => loadStyle("css/icomoon.css"))
        .then(() => {
            alert('All styles are loaded!');
        }).catch(err => alert(err));
}

It's really cool, right? This is a way to decide the priority of the styles using Promises.

To see a multi-style loading implementation see: https://stackoverflow.com/a/63936671/13720928

answered Nov 4, 2020 at 16:47

There is a general jquery plugin that loads css and JS files synch and asych on demand. It also keeps track off what is already been loaded :) see: http://code.google.com/p/rloader/

answered Dec 12, 2010 at 12:01

Here's a way with jQuery's element creation method (my preference) and with callback onLoad:

var css = $("<link>", {
  "rel" : "stylesheet",
  "type" :  "text/css",
  "href" : "style.css"
})[0];

css.onload = function(){
  console.log("CSS IN IFRAME LOADED");
};

document
  .getElementsByTagName("head")[0]
  .appendChild(css);

answered Oct 22, 2014 at 18:18

Lounge9Lounge9

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Below a full code using for loading JS and/or CSS

function loadScript(directory, files){
  var head = document.getElementsByTagName("head")[0]
  var done = false
  var extension = '.js'
  for (var file of files){ 
    var path = directory + file + extension 
    var script = document.createElement("script")
    script.src = path        
    script.type = "text/javascript"
    script.onload = script.onreadystatechange = function() {
        if ( !done && (!this.readyState ||
            this.readyState == "loaded" || this.readyState == "complete") ) {
            done = true
            script.onload = script.onreadystatechange = null   // cleans up a little memory:
            head.removeChild(script)  // to avoid douple loading
        }
  };
  head.appendChild(script) 
  done = false
 }
}

function loadStyle(directory, files){
  var head = document.getElementsByTagName("head")[0]
  var extension = '.css'
  for (var file of files){ 
   var path = directory + file + extension 
   var link = document.createElement("link")
   link.href = path        
   link.type = "text/css"
   link.rel = "stylesheet" 
   head.appendChild(link) 
 }
}

(() => loadScript('libraries/', ['listen','functions', 'speak', 'commands', 'wsBrowser', 'main'])) ();
(() => loadScript('scripts/', ['index'])) ();

(() => loadStyle('styles/', ['index'])) ();

answered Sep 6, 2016 at 12:08

Hasan A YousefHasan A Yousef

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1

Here's a one line example, that uses plain JavaScript to inject a CSS link into the head element based on the filename portion of the URL:

document.head.innerHTML += '<link rel="stylesheet" href="css/style.css">';

Most browsers support it. See the browser compatibility.

answered Sep 16, 2020 at 18:52

1

The YUI library might be what you are looking for. It also supports cross domain loading.

If you use jquery, this plugin does the same thing.

answered Feb 22, 2009 at 14:04

AnandAnand

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var elem = document.createElement('link');
elem.rel = ' stylesheet'
elem.href= 'style.css';//Link of the css file
document.head.appendChild(elem);

answered Jul 31, 2020 at 10:36

2

I'd like to share one more way to load not only css but all the assets (js, css, images) and handle onload event for the bunch of files. It's async-assets-loader. See the example below:

<script src="https://unpkg.com/async-assets-loader"></script>
<script>
var jsfile = "https://code.jquery.com/jquery-3.4.1.min.js";
var cssfile = "https://cdnjs.cloudflare.com/ajax/libs/materialize/1.0.0/css/materialize.min.css";
var imgfile = "https://logos.keycdn.com/keycdn-logo-black.png";
var assetsLoader = new asyncAssetsLoader();
assetsLoader.load([
      {uri: jsfile, type: "script"},
      {uri: cssfile, type: "style"},
      {uri: imgfile, type: "img"}
    ], function () {
      console.log("Assets are loaded");
      console.log("Img width: " + assetsLoader.getLoadedTags()[imgfile].width);
    });
</script> 

According to the async-assets-loader docs

answered Nov 26, 2019 at 18:42

v.babakv.babak

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Answer from future. In 2022, we have import assertions api for import css file.

import mycss from "./style/mycss.css" assert { type: "css" };
    console.log(mycss);

Browser support: till september 2022, only chromium based browsers supported.

Read more at: v8 import assertions post

tc39 github t39 import assertions proposal

answered Sep 22 at 13:26

var fileref = document.createElement("link")
fileref.setAttribute("rel", "stylesheet")
fileref.setAttribute("type", "text/css")
fileref.setAttribute("th:href", "@{/filepath}")
fileref.setAttribute("href", "/filepath")

I'm using thymeleaf and this is work fine. Thanks

answered Oct 21, 2014 at 4:45

1

use:

document.getElementById("of head/body tag")
        .innerHTML += '<link rel="stylesheet" type="text/css" href="style.css">';

acarlstein

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answered Aug 10, 2020 at 20:04

0

This function uses memorization. And could be called many times with no conflicts of loading and running the same stylesheet twice. Also it's not resolving sooner than the stylesheet is actually loaded.

const loadStyle = function (src) {
    let cache = [];
    return function (src) {
        return cache[src] || (cache[src] = new Promise((resolve, reject) => {
            let s = document.createElement('link');
            s.rel = 'stylesheet';
            s.href = src;
            s.onload = resolve;
            s.onerror = reject;
            document.head.append(s);
        }));
    }
}();

Please notice the parentheses () after the function expression.

Parallel loading of stylesheets:

Promise.all([
    loadStyle('/style1.css'),
    loadStyle('/style2.css'),
    // ...
]).then(() => {
    // do something
})

You can use the same method for dynamic loading scripts.

answered May 2 at 5:14

vatavalevatavale

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