Detect CSS Transitions Using JavaScript (And Without Modernizr)

Detect CSS transitions using Javascript (and without modernizr)?

Perhaps something like this. Basically it's just looking to see if the CSS transition property has been defined:

function supportsTransitions() {
    var b = document.body || document.documentElement,
        s = b.style,
        p = 'transition';

    if (typeof s[p] == 'string') { return true; }

    // Tests for vendor specific prop
    var v = ['Moz', 'webkit', 'Webkit', 'Khtml', 'O', 'ms'];
    p = p.charAt(0).toUpperCase() + p.substr(1);

    for (var i=0; i<v.length; i++) {
        if (typeof s[v[i] + p] == 'string') { return true; }
    }

    return false;
}

Adapted from this gist. All credit goes there.

Detect CSS transitions using Javascript (and without modernizr)?

Perhaps something like this. Basically it's just looking to see if the CSS transition property has been defined:

function supportsTransitions() {
    var b = document.body || document.documentElement,
        s = b.style,
        p = 'transition';

    if (typeof s[p] == 'string') { return true; }

    // Tests for vendor specific prop
    var v = ['Moz', 'webkit', 'Webkit', 'Khtml', 'O', 'ms'];
    p = p.charAt(0).toUpperCase() + p.substr(1);

    for (var i=0; i<v.length; i++) {
        if (typeof s[v[i] + p] == 'string') { return true; }
    }

    return false;
}

Adapted from this gist. All credit goes there.

How would I detect CSS Transition support on :before pseudo-elements with javascript?

Thanks to @Asad for digging up some handy code, I was able to come up with a nice solution here's the jQuery version:

$(function() {
  var isTransitionSupported = (function (pseudo, transProp, transPropStart, transPropEnd) {
    var id = pseudo + transProp + '-' + (new Date()).valueOf(),
        prefixes = ['o', 'ms', 'moz', 'webkit'],
        prop = "transition: " + transProp + " 99s linear;",
        allprops = (function () {
          var props = "";
          for (var l = prefixes.length; l--;) {
            props += "-" + prefixes[l] + "-" + prop;
          }
          return props + prop;
        }()),
        $css = $("<style>" +
                 "#" + id + "{position:absolute;left:-999em;}" + 
                 "#" + id + ":" + pseudo + "{display:block;content:'M';" + transProp + ":" + transPropStart + ";}" + 
                 "#" + id + ".t:" + pseudo + "{" + allprops + transProp + ":" + transPropEnd + ";}" + 
                 "</style>"),
        $bct = $('<div id="' + id + '" />');

      $css.appendTo("head");
      $bct.appendTo("body");

      try {
        // get style value before any changes
        window.getComputedStyle($bct[0], ':' + pseudo).getPropertyValue(transProp);

        $bct.addClass("t");

        // test style after changes
        return (window.getComputedStyle($bct[0], ':' + pseudo).getPropertyValue(transProp) !== transPropEnd);
      } catch (e) {}
      return false;
    }("before", "width", "0px", "1000px"));
});

Here's a version that doesn't use jQuery:

var isTransitionSupported = (function (pseudo, transProp, transPropStart, transPropEnd) {
    var ticks = (new Date()).valueOf(),
        id = pseudo + transProp + '-' + ticks,
        prefixes = ['o', 'ms', 'moz', 'webkit'],
        prop = "transition: " + transProp + " 99s linear;",
        allprops = (function () {
            var props = "";
            for (var l = prefixes.length; l--;) {
                props += "-" + prefixes[l] + "-" + prop;
            }
            return props + prop;
        }()),
        body = document.body || document.createElement('body'),
        node = document.createElement('div'),
        css = "<style>" +
                    "#" + id + "{position:absolute;left:-999em;}" + 
                    "#" + id + ":" + pseudo + "{display:block;content:'M';" + transProp + ":" + transPropStart + ";}" + 
                    "#" + id + ".t" + ticks + ":" + pseudo + "{" + allprops + transProp + ":" + transPropEnd + ";}" + 
                    "</style>",
        bct = document.createElement('div'),
        isSupported = false;

    bct.id = id;
    node.innerHTML += css;
    node.appendChild(bct);
    body.appendChild(node);

    try {
        // get style value before any changes
        window.getComputedStyle(bct, ':' + pseudo).getPropertyValue(transProp);

        bct.className += "t" + ticks;

        // test style after changes
        isSupported = (window.getComputedStyle(bct, ':' + pseudo).getPropertyValue(transProp) !== transPropEnd);
    } catch (e) {}

    node.parentNode.removeChild(node);

    return isSupported;
}("before", "width", "0px", "1000px"));

document.documentElement.className += ' ' + (isTransitionSupported ? '' : 'no-') + "pseudo-trans";

Here's all that code in a gist on github, if anyone wants to fork and improve it.

Detect support for transition with JavaScript

Modernizr will detect this for you. Use this link to create a custom download build that only contains CSS3 2D and/or 3D transitions.

Once it's run, you can either test for the csstransitions class on the html tag (CSS), or in JavaScript, test if Modernizr.csstransitions is true.

More docs: http://modernizr.com/docs/#csstransitions

CSS3 transition events

W3C CSS Transitions Draft

The completion of a CSS Transition generates a corresponding DOM Event. An event is fired for each property that undergoes a transition. This allows a content developer to perform actions that synchronize with the completion of a transition.

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Webkit

To determine when a transition completes, set a JavaScript event listener function for the DOM event that is sent at the end of a transition. The event is an instance of WebKitTransitionEvent, and its type is webkitTransitionEnd.

box.addEventListener( 'webkitTransitionEnd', 
    function( event ) { alert( "Finished transition!" ); }, false );

Mozilla

There is a single event that is fired when transitions complete. In Firefox, the event is transitionend, in Opera, oTransitionEnd, and in WebKit it is webkitTransitionEnd.

Opera

There is one type of transition event
available. The oTransitionEnd event
occurs at the completion of the
transition.

Internet Explorer

The transitionend event occurs at the completion of the transition. If the transition is removed before completion, the event will not fire.

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Stack Overflow: How do I normalize CSS3 Transition functions across browsers?

Using Modernizr and jQuery to Animate if CSS3 Transitions Don't Exist

Solved this myself. The way I did was like this

<!doctype html>
<html>
    <head>
        <title>Modernizr + jQuery Testing</title>
        <script type="text/javascript" src="modernizr.js"></script>
        <script type="text/javascript" src="jquery.js"></script>
        <script type="text/javascript">
        if(!Modernizr.csstransitions) { // Test if CSS transitions are supported
            $(function() {
                $('#js').hover(function(){
                    $(this).animate({width:'50px',height:'50px'},{queue:false,duration:500});
                }, function(){
                    $(this).animate({width:'100px',height:'100px'},{queue:false,duration:500});
                });
            });
        }
        </script>
        <style type="text/css">
            body {
                margin: 0;
                padding: 0;
            }
            div {
                border: 1px solid red;
                height: 100px;
                margin: 25px auto;
                width: 100px;
            }
            #css {
                transition: height .5s, width .5s;
                -khtml-transition: height .5s, width .5s;
                -moz-transition: height .5s, width .5s;
                -o-transition: height .5s, width .5s;
                -webkit-transition: height .5s, width .5s;
            }
            #css:hover {
                height: 50px;
                width: 50px;
            }
        </style>
    </head>

    <body>
        <div id="js">
            JS
        </div>
        <div id="css">
            CSS
        </div>
    </body>
</html>

That worked perfectly. The CSS one only animates in new browsers (because that's the only place it can) and the JS one only animates in old browsers. If you use this script, you can get modernizr from http://www.modernizr.com/ and jQuery from http://www.jquery.com/ (of course).

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