random_class.js

random_class.js

/*
 * RandomClass -        A jQuery plugin to add a random class from a selection
 * of classes to an element.
 *
 * Copyright (c) 2010 Fredi Bach
 * www.fredibach.ch
 *
 * Usage:

        $("p span").randomClass( [ 'color1','color2','color3' ] );

 * Or with options:

        $("p span").randomClass( [ 'color1','color2','color3' ], { randomness: 'pattern', removeClasses: true } );

 * Plugin page: http://fredibach.ch/jquery-plugins/randomclass.php
 *
 */
(function($) {

        $.fn.randomClass=function(classes,settings){
            var defaults = {
                randomness: 'default',
                removeClasses: false
            };
            var s = $.extend(defaults, settings);

            if (s.randomness == 'pattern'){
                classes = shuffle(classes);
            }

            var p = -1;
            var cnt = 0;

            this.each( function(i) {
                if (s.removeClasses){
                    for (c in classes){
                        var cn = classes[c];
                        if ( $(this).hasClass(cn) ){
                            $(this).removeClass(cn);
                        }
                    }
                }
                if (s.randomness == 'pattern'){
                    cnt++;
                    $(this).addClass(classes[cnt%classes.length]);
                } else {
                    do {
                        var r = Math.floor(Math.random() * classes.length);
                    } while ((p == r || $(this).prev().prev().hasClass(classes[r])) && s.randomness == 'successive');

                    $(this).addClass(classes[r]);
                    p = r;
                }
            });

            shuffle = function(o){
                for(var j, x, i = o.length; i; j = parseInt(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
                return o;
            };

            return this;
        };

})(jQuery);