美丽的jquery

$.fn.alternateRowColors = function(){  //改变颜色的插件
    $('tbody tr:odd', this)
        .removeClass('even').addClass('odd');
    $('tbody tr:even', this)
        .removeClass('odd').addClass('even');
    };

$(document).ready(function(){
    $('table.sortable').each(function(){
        var $table = $(this);
        $table.alternateRowColors();
        $('th', $table).each(function(column){  //遍历表头
            var $header = $(this);  //遍历的当前表头
            var findSortKey;
            if ($header.is('.sort-alpha')){
                findSortKey = function($cell){
                    return $cell.find('.sort-key').text().toUpperCase()
                        + ' ' + $cell.text().toUpperCase();
                };
            }
            else if ($header.is('.sort-numberic')){
                findSortKey = function($cell){
                    var key = $cell.text().replace(/^[^\d.]*/, '');
                    key = parseFloat(key);
                    return isNaN(key) ? 0 : key;
                };
            }
            else if ($header.is('.sort-date')){
                findSortKey = function($cell){
                    return Date.parse('1 ' + $cell.text());
                };
            }
            if (findSortKey){
                $header.addClass('clickable').hover(function(){
                    $header.addClass('hover');
                }, function(){
                    $header.removeClass('hover');
                }).click(function(){
                    var sortDirection = 1;
                    if ($header.is('.sorted-asc')){
                        sortDirection = - 1;
                    }
                    var rows = $table.find('tbody > tr').get(); //表格行的dom数组
                    $.each(rows, function(index, row){
                        var $cell = $(row).children('td').eq(column); //指定列号的单元格
                        row.sortKey = findSortKey($cell);
                    });
                    rows.sort(function(a, b){
                        if (a.sortKey < b.sortKey) return -sortDirection;
                        if (a.sortKey > b.sortKey) return sortDirection;
                        return 0;
                        });
                        $.each(rows, function(index, row){
                            $table.children('tbody').append(row);
                            row.sortKey = null;
                            });
                            $table.find('th').removeClass('sorted-asc')
                                .removeClass('sorted-desc');
                            if (sortDirection == 1){
                                $header.addClass('sorted-asc');
                            }
                            else {
                                $header.addClass('sorted-desc');
                            }
                            $table.find('td').removeClass('sorted')
                                .filter(':nth-child('+(column + 1)+')')
                                .addClass('sorted');
                            $table.alternateRowColors();
                    });
            }
            });
        });
    });