Question

When I add the transition line into my code it breaks jQuery. How can I fix it?

a(this).next().css({
    left: c,
    transition: 'opacity 1s ease-in-out'
});

I’m trying to set up a fade from one div to the next inside a slider

Answer 1

Step 1) Remove the semi-colon, it’s an object you’re creating…

a(this).next().css({
    left       : c,
    transition : 'opacity 1s ease-in-out';
});

to

a(this).next().css({
    left       : c,
    transition : 'opacity 1s ease-in-out'
});

Step 2) Vendor-prefixes… no browsers use transition since it’s the standard and this is an experimental feature even in the latest browsers:

a(this).next().css({
    left             : c,
    WebkitTransition : 'opacity 1s ease-in-out',
    MozTransition    : 'opacity 1s ease-in-out',
    MsTransition     : 'opacity 1s ease-in-out',
    OTransition      : 'opacity 1s ease-in-out',
    transition       : 'opacity 1s ease-in-out'
});

Here is a demo: http://jsfiddle.net/83FsJ/

Step 3) Better vendor-prefixes… Instead of adding tons of unnecessary CSS to elements (that will just be ignored by the browser) you can use jQuery to decide what vendor-prefix to use:

$('a').on('click', function () {
    var myTransition = ($.browser.webkit)  ? '-webkit-transition' :
                       ($.browser.mozilla) ? '-moz-transition' : 
                       ($.browser.msie)    ? '-ms-transition' :
                       ($.browser.opera)   ? '-o-transition' : 'transition',
        myCSSObj     = { opacity : 1 };

    myCSSObj[myTransition] = 'opacity 1s ease-in-out';
    $(this).next().css(myCSSObj);
});​

Here is a demo: http://jsfiddle.net/83FsJ/1/

Also note that if you specify in your transition declaration that the property to animate is opacity, setting a left property won’t be animated.