Question

Is it possible to get the CSSStyleSheet object (document.styleSheets[0]) from a HTMLStyleElement (document.createElement('style')) ?

I would like to dynamically add css rules to a not-inserted-in-the-document-yet <style> element.

Answer 1

You can add rules before you add the style element to the document.

A couple notes-

Older IE browsers cannot add child nodes to a style element, so assign to the element’s styleSheet.csstext property for them.
Make sure you append the new element to the head of the document.

function addStyle(css, media1, title1){
    var el= document.createElement('style');
    el.type= 'text/css';
    if(media1) el.media= media1;
    if(title1) el.title= title1;
    if(el.styleSheet) el.styleSheet.cssText= css;//IE
    else{
        el.appendChild(document.createTextNode(css));
    }
    //return el without the next line if you want to append it later
    return document.getElementsByTagName('head')[0].appendChild(el);

}

var cs1= [
    '#yw_psq, #yw_psq h2{background-color: green; color: white;}',
    '#yw_psq_div{margin: 1ex; position: relative; text-align: center;}',
    '#ps_counter{color: white; margin: 1ex 0 0 0; text-align: center;}',
    '#pzsq_grid  button{cursor: pointer; font-size: 1.2em; width: 100%;}',
    '#delaySpan{font-weight: bold; margin-left: 1em;}'
]

addStyle(cs1.join('\n'),'screen','yw_psq');