JavaScript实现前端分页控件

function pagination(obj){
    /*pageIndex: index,
pageSize: size,
count:   count,  
container: container,
fn  :   fn
     */
    if(!obj||typeof obj!="object"){
        return false;
    }
    var pageIndex= obj.pageIndex||1,
      pageSize=obj.pageSize||10,
      count= obj.count||0,
      container= obj.container,
      callback=obj.fn||function(){};
    var pageCount =Math.ceil(count/pageSize); 
    if(pageCount==0){
        return false ;
    }  
    if(pageCount<pageIndex){
        return false;
    }
    /*事件绑定*/
    function bindEvent(){
        //上一页事件
        $(container).find(">ul>.pg-prev").unbind("click").bind("click",function(){
                if(pageIndex <=1){
                return false ;
                }
                if(typeof callback=="function"){
                pageIndex--;
                pageIndex = pageIndex<1?1:pageIndex;
                obj.pageIndex= pageIndex;
                callback(pageIndex);
                pagination(obj);
                }
                });
        //下一页事件
        $(container).find(">ul>.pg-next").unbind("click").bind("click",function(){
                if(pageIndex ==pageCount){
                return false ;
                }
                if(typeof callback=="function"){
                pageIndex++;
                pageIndex =pageIndex >pageCount?pageCount:pageIndex;
                obj.pageIndex= pageIndex;
                callback(pageIndex);
                pagination(obj);
                }
                });
        $(container).find(">ul>li:not(.pg-more):not(.pg-prev):not(.pg-next)").unbind("click").bind("click",function(){
                pageIndex= +$(this).html();
                pageIndex = isNaN(pageIndex)?1:pageIndex;
                obj.pageIndex= pageIndex;
                if(typeof callback=="function"){
                callback(pageIndex);
                pagination(obj);
                }
                });
    };

    /*画样式*/
    function printHead(){
        var html=[];
        html.push('<li class="pg-prev '+(pageIndex==1?"pg-disabled":"")+'">上一页</li>');
        return html.join("");
    }
    function printBody(){
        var html=[];
        var render=function(num,start){
            start=start||1;
            for(var i=start;i<=num;i++){
                html.push('<li class="'+(pageIndex==i?"pg-on":"")+'">'+i+'</li>');
            }
        }
        if(pageCount<=7){
            render(pageCount);
        }else{
            if(pageIndex <4){
                render(4);
                html.push('<li class="pg-more">...</li>');
                html.push('<li >'+pageCount+'</li>');    
            }else{
                html.push('<li >1</li>');  
                html.push('<li class="pg-more">...</li>');
                if(pageCount-pageIndex>3){
                    render(pageIndex+1,pageIndex-1);
                    html.push('<li class="pg-more">...</li>');
                    html.push('<li >'+pageCount+'</li>');
                }else{
                    render(pageCount,pageCount-3);
                }
            }
        }
        return html.join("");
    }
    function printTail(){
        var html=[];
        html.push('<li class="pg-next '+(pageIndex==pageCount?"pg-disabled":"")+'">下一页</li>');
        return html.join("");
    }
    function show(){
        container.innerHTML= '<ul>'+printHead()+printBody()+printTail()+'</ul>';
    }
    show();
    bindEvent();
}