vanilla javascript classList manipulation on hover

technopeasant picture technopeasant · May 26, 2013 · Viewed 10.1k times · Source

Trying to do some really basic class manipulation on hover and load for a splash page. Not sure why it's not working- then again, never written in Vanilla before.

jsFiddle example.

basic DOM:

<body>
    <article>
        <p>test</p>
    </article>
</body>

JavaScript:

var bod     = document.getElementsByTagName('body')[0],
    article = document.getElementsByTagName('article')[0];

article.onMouseOver = function(){

    bod.classList.add('focus');
}

article.onMouseOut = function(){

    bod.classList.remove('focus');
}

window.onLoad = function(){

    bod.classList.remove('loading');
}

Answer

Dory Zidon picture Dory Zidon · May 26, 2013

use lowercase handlers:

article.onmouseover

But in general it's better to use the addEventListner method. The .onevent method allows for only one handler and its also quick and dirty. however it messes up the code and the html and in some cases you might even remove some other important code from running, that is why the addEventListener is better, as it chains and you can have multiple handlers listening to one event, which is the proper form.

Here is a wonderful answer from another stackoverflow user on the exact differences (however I pretty much sum it up for you in the above paragraph).. AddEventListener vs element.onevent

here is the fixed Fiddle using the proper event handling: http://jsfiddle.net/hXjFz/1/