Question

I display 40+ boxes on a page:

<div id="primary">
    <div class="box" style="background:....">
        <a href="" style="color:....">box1</a>
    </div>
    <div class="box" style="background:....">
        <a href="" style="color:....">box2</a>
    </div>
    ....
</div>

As you can see I set background-color and text-color. On hover I want to swap the colors:

      $(".box").each( function () {
          $(this).data('baseColor',$(this).css('background-color'));
          $(this).find('a').data('fontColor',$(this).css('color'));
          $(this).hover(function() {
            $(this).animate({ backgroundColor:
                       $(this).data('fontColor') }, 500);
          },function() {
            $(this).animate({ backgroundColor: 
                       $(this).data('baseColor') }, 1000);
          });
        });

The animation of the background-color works but I can not change the font color of the a element. Any ideas?

Answer 1

As @Brandon mentioned, you need jQuery UI (or something 😉 to animate non-integer properties.

The bigger issue is the change of context in your each callback: inside the hover callback methods, the value of this won’t always be what you want. Also, creating new jQuery objects (with $(...)) is relatively expensive. Try:

var cssBox = {
    backgroundColor: $('.box').css('background-color'),
    color: $('.box').css('color')
};

var cssLink = {
    backgroundColor: $('.box > a').css('background-color'),
    color: $('.box > a').css('color')
};

$(".box").each(function() {
    var $this = $(this),
        $this_a = $this.children('a');

    $this.data('baseColor', $this.css('background-color'));
    $this.data('fontColor', $this_a.css('color'));
    $this.hover(function() {
        $this.animate(cssLink, 500);
        $this_a.animate(cssBox, 500);
    }, function() {
        $this.animate(cssBox, 1000);
        $this_a.animate(cssLink, 1000);
    });
});

Demo here.