Dynamically load and unload stylesheets

Question

I\'ve searched various posts and forums but can\'t find the right answer. I need to find a way to dynamically load and unload stylesheets.

I\'m building a website th

Answer 1

I managed to get this working with a little tweaking of:

http://www.javascriptkit.com/javatutors/loadjavascriptcss.shtml

Content of the link:

function loadjscssfile(filename, filetype){
    if (filetype=="js"){ //if filename is a external JavaScript file
        var fileref=document.createElement('script')
        fileref.setAttribute("type","text/javascript")
        fileref.setAttribute("src", filename)
    }
    else if (filetype=="css"){ //if filename is an external CSS file
        var fileref=document.createElement("link")
        fileref.setAttribute("rel", "stylesheet")
        fileref.setAttribute("type", "text/css")
        fileref.setAttribute("href", filename)
    }
    if (typeof fileref!="undefined")
        document.getElementsByTagName("head")[0].appendChild(fileref)
}

loadjscssfile("myscript.js", "js") //dynamically load and add this .js file
loadjscssfile("javascript.php", "js") //dynamically load "javascript.php" as a JavaScript file
loadjscssfile("mystyle.css", "css") ////dynamically load and add this .css file

function removejscssfile(filename, filetype){
    var targetelement=(filetype=="js")? "script" : (filetype=="css")? "link" : "none" //determine element type to create nodelist from
    var targetattr=(filetype=="js")? "src" : (filetype=="css")? "href" : "none" //determine corresponding attribute to test for
    var allsuspects=document.getElementsByTagName(targetelement)
    for (var i=allsuspects.length; i>=0; i--){ //search backwards within nodelist for matching elements to remove
    if (allsuspects[i] && allsuspects[i].getAttribute(targetattr)!=null && allsuspects[i].getAttribute(targetattr).indexOf(filename)!=-1)
        allsuspects[i].parentNode.removeChild(allsuspects[i]) //remove element by calling parentNode.removeChild()
    }
}

removejscssfile("somescript.js", "js") //remove all occurences of "somescript.js" on page though in most browser this does not unload the script
removejscssfile("somestyle.css", "css") //remove all occurences "somestyle.css" on page

Just FYI: For js scripts, this will remove a script element from the DOM but most browser will not unload the js code i.e. anything defined in the js file will stay defined.

Answer 2

If you're only changing colors of divs in your page, I would suggest using JQuery's ".css".

With this you change the css styling on divs or classes with the click of a link.
The following changes the background color of any div with the class "class_name" to black:

$(".class_name").css("background-color","#000000");

For more information on the jquery syntax look at their link here: http://api.jquery.com/css/

Answer 3

To Load css dynamically

var headID = document.getElementsByTagName("head")[0];
var cssNode = document.createElement('link');
cssNode.type = 'text/css';
cssNode.rel = 'stylesheet';
cssNode.href = 'FireFox.css';
cssNode.media = 'screen';
headID.appendChild(cssNode);

To Unload css file

function removefile(filename, filetype) {
var targetElement = "link"; 
var targetAttr = "href"; 

var allCtrl = document.getElementsByTagName(targetElement);
for (var i=allCtrl.length; i>=0; i--)  { //search backwards within nodelist for matching elements to remove
if (allCtrl[i] && allCtrl[i].getAttribute(targetAttr)!=null && allCtrl[i].getAttribute(targetAttr).indexOf(filename)!=-1);
allCtrl[i].parentNode.removeChild(allCtrl[i]);
}
}