How to create a <style> tag with Javascript

Question

I'm looking for a way to insert a <style> tag into an HTML page with JavaScript.

The best way I found so far:

var divNode = document.createElement("div");
divNode.innerHTML = "<br><style>h1 { background: red; }</style>";
document.body.appendChild(divNode);

This works in Firefox, Opera and Internet Explorer but not in Google Chrome. Also it's a bit ugly with the <br> in front for IE.

Does anyone know of a way to create a <style> tag that

1. Is nicer

2. Works with Chrome?

Or maybe

1. This is a non-standard thing I should avoid

2. Three working browsers are great and who uses Chrome anyway?

Answer 1

Try adding the style element to the head rather than the body.

This was tested in IE (7-9), Firefox, Opera and Chrome:

var css = 'h1 { background: red; }',
    head = document.head || document.getElementsByTagName('head')[0],
    style = document.createElement('style');

style.type = 'text/css';
if (style.styleSheet){
  // This is required for IE8 and below.
  style.styleSheet.cssText = css;
} else {
  style.appendChild(document.createTextNode(css));
}

head.appendChild(style);

Answer 2

var list = document.querySelector("head");
list.innerHTML += '<style>
                      h3.header-6.basket-item--header 
                      span.cusplus {
                         color:#c00; 
                      }.
                      cusname{
                         color:grey;font-size:14px;
                      }
                  </style>';

200% working code,example above

Answer 3

If the problem you're facing is injecting a string of CSS into a page it is easier to do this with the <link> element than the <style> element.

The following adds p { color: green; } rule to the page.

<link rel="stylesheet" type="text/css" href="data:text/css;charset=UTF-8,p%20%7B%20color%3A%20green%3B%20%7D" />

You can create this in JavaScript simply by URL encoding your string of CSS and adding it the HREF attribute. Much simpler than all the quirks of <style> elements or directly accessing stylesheets.

let linkElement: HTMLLinkElement = this.document.createElement('link');
linkElement.setAttribute('rel', 'stylesheet');
linkElement.setAttribute('type', 'text/css');
linkElement.setAttribute('href', 'data:text/css;charset=UTF-8,' + encodeURIComponent(myStringOfstyles));

This will work in IE 5.5 upwards

Answer 4

Oftentimes there's a need to override existing rules, so appending new styles to the HEAD doesn't work in every case.

I came up with this simple function that summarizes all not valid "append to the BODY" approaches and is just more convenient to use and debug (IE8+).

window.injectCSS = (function(doc){
    // wrapper for all injected styles and temp el to create them
    var wrap = doc.createElement('div');
    var temp = doc.createElement('div');
    // rules like "a {color: red}" etc.
    return function (cssRules) {
        // append wrapper to the body on the first call
        if (!wrap.id) {
            wrap.id = 'injected-css';
            wrap.style.display = 'none';
            doc.body.appendChild(wrap);
        }
        // <br> for IE: http://goo.gl/vLY4x7
        temp.innerHTML = '<br><style>'+ cssRules +'</style>';
        wrap.appendChild( temp.children[1] );
    };
})(document);

Demo: codepen, jsfiddle

Answer 5

An example that works and are compliant with all browsers :

var ss = document.createElement("link");
ss.type = "text/css";
ss.rel = "stylesheet";
ss.href = "style.css";
document.getElementsByTagName("head")[0].appendChild(ss);

Answer 6

Here's a script which adds IE-style createStyleSheet() and addRule() methods to browsers which don't have them:

if(typeof document.createStyleSheet === 'undefined') {
    document.createStyleSheet = (function() {
        function createStyleSheet(href) {
            if(typeof href !== 'undefined') {
                var element = document.createElement('link');
                element.type = 'text/css';
                element.rel = 'stylesheet';
                element.href = href;
            }
            else {
                var element = document.createElement('style');
                element.type = 'text/css';
            }

            document.getElementsByTagName('head')[0].appendChild(element);
            var sheet = document.styleSheets[document.styleSheets.length - 1];

            if(typeof sheet.addRule === 'undefined')
                sheet.addRule = addRule;

            if(typeof sheet.removeRule === 'undefined')
                sheet.removeRule = sheet.deleteRule;

            return sheet;
        }

        function addRule(selectorText, cssText, index) {
            if(typeof index === 'undefined')
                index = this.cssRules.length;

            this.insertRule(selectorText + ' {' + cssText + '}', index);
        }

        return createStyleSheet;
    })();
}

You can add external files via

document.createStyleSheet('foo.css');

and dynamically create rules via

var sheet = document.createStyleSheet();
sheet.addRule('h1', 'background: red;');