基于jquery实现简单的分页控件

/*分页控件v1.0
 date:2015.08.26
*/
(function(window,$){
  $.fn.pagination = function(options){
    var _dftOpts = {
      count:0,//总数
      size:10,//每页数量
      index:1,//当前页
      lrCount:5,//当前页左右最多显示的数量
      lCount:0,//最开始预留的数量
      rCount:0,//最后预留的数量
      first:"首页",
      last:"尾页",
      before:"上一页",
      next:"下一页",     
      callback:null,//点击事件
      beforeRender:null//项呈现前
    };
    $.extend(_dftOpts,options);
    var count = _dftOpts.count;
    if(count <= 0) return;
    var _ellipsis = "...";
    var _size = _dftOpts.size > 0 ? (_dftOpts.size > count ? count : _dftOpts.size) : 1;
    var _page = Math.ceil(count / _size);
    var _index = _dftOpts.index > 0 ? (_dftOpts.index > _page ? _page : _dftOpts.index) : 1;
    var _lrcount = _dftOpts.lrCount * 2 + 1 > _page ? parseInt((_page - 1) / 2) : _dftOpts.lrCount;    
    var _continueCount = _lrcount * 2 + 1;
    var _lCount = _dftOpts.lCount <= 0 ? 0 : (_dftOpts.lCount > _page ? _page - 1 : _dftOpts.lCount);
    var _rCount = _dftOpts.rCount <= 0 ? 0 : (_dftOpts.rCount > _page ? _page - 1 : _dftOpts.rCount);
    var _first = _dftOpts.first;
    var _before = _dftOpts.before;
    var _last = _dftOpts.last;
    var _next = _dftOpts.next;
    var _FromTo;
    var _url = location.pathname + location.search + "#p";
    var jthis = this;
    var jPager = $("<div>",{"class":"pager"});    
    initJPager();    
    jthis.append(jPager);
    regisiterEvent();
    return jthis;
     
    /*function*/    
    function initJPager(){
      _FromTo = GetFromTo();
      var from = _FromTo.from;
      var to = _FromTo.to;
      var before = _index <= 1 ? 1 : _index - 1;
      var next = _index >= _page ? _page : _index + 1;
      var beforeLast = _page - 1;
      var jPrevs,jNexts;
      var i;
          
      //前   
      if(from === 2 && _lCount > 0){
        appendLink(1);
      }else if(from > _lCount + 1){
        for(i = 0;i < _lCount;i++){
          appendLink(i + 1);          
        }
        if(_lCount > 0){
          appendEllipsis();
        }
      }else{        
        for(i = 1;i < from;i++){
          appendLink(i);
        }
      }
       
      //连续部分
      for(i = from;i <= to;i++){
        if(i === _index){              
          appendLink(i,true);
        }else{
          appendLink(i);
        }
      }
       
      //后
      if(to === beforeLast && _rCount > 0){      
        appendLink(_page);
      }else if(to < _page - _rCount){
        if(_rCount > 0){
          appendEllipsis();
        }
        for(i = _page - _rCount;i < _page;i++){
          appendLink(i + 1);
        }
      }else{
        for(i = to;i < _page;i++){
          appendLink(i + 1);
        }
      }
       
      appendFirstAndLast();
    }
    function GetFromTo(){
      var from,to;
      from = _index - _lrcount;
      if(from <= 1){
        return {from:1,to:_continueCount};
      }
      if(_page - _index < _lrcount){
        from = _page - _continueCount + 1;        
        return {from:from,to:_page};
      }
      to = _index + _lrcount;
      to = to > _page ? _page : to;    
      return {from:from,to:to};      
    }    
    function appendLink(index,active){
      var jA = $("<a>",{text:index,href:_url+index});
      if(active){
        jA.addClass("active");
      }
      if(_dftOpts.beforeRender){
        _dftOpts.beforeRender(jA);
      }
      jPager.append(jA);
    }
    function appendFirstAndLast(){
      var jFirst = $("<a>",{text:_first});
      var jBefore = $("<a>",{text:_before});
      var jLast = $("<a>",{text:_last});
      var jNext = $("<a>",{text:_next});
      jPager.append(jNext).append(jLast);
      jBefore.insertBefore(jPager.find("a").first());
      jFirst.insertBefore(jBefore);
      if(_index === 1){
        jFirst.addClass("disabled");
        jBefore.addClass("disabled");
      }else{
        jFirst.attr("href",_url+1);
        jBefore.attr("href",_url+(_index-1));
      }
      if(_index === _page){
        jLast.addClass("disabled");
        jNext.addClass("disabled");
      }else{
        jLast.attr("href",_url+_page);          
        jNext.attr("href",_url+(_index+1));
      }     
    }
    function appendEllipsis(){
      jPager.append(_ellipsis);
    }
    //event
    function regisiterEvent(){
      jPager.on("mouseenter","a",function(){
        var jthis = $(this);
        if(!jthis.hasClass("active") && !jthis.hasClass("disabled")){
          jthis.addClass("hover");
        }
      }).on("mouseout","a",function(){
        var jthis = $(this);
        if(!jthis.hasClass("active")){
          jthis.removeClass("hover");
        }
      }).on("click","a",function(){
        var jItem = $(this);
        if(jItem.hasClass("disabled")){
          return;
        }
        var text = jItem.text();
        var index = 0;
        switch(text){
          case _first:
            index = 1;
            break;
          case _before:
            index = _index - 1;
            break;
          case _last:
            index = _page;
            break;
          case _next:
            index = _index + 1;
            break;
          default:
            index = parseInt(text);
            break;
        }        
        var callback = _dftOpts.callback;
        var newOpts;
        _dftOpts.index = index;
        jPager.remove();
        if(callback){
          newOpts = callback(_dftOpts);
        }
        if(newOpts){
          _dftOpts = newOpts;
        }
        jthis.pagination(_dftOpts);        
      });           
    }
  }
})(window,$);

.pager{height:30px;line-height:30px;font-size: 12px;margin: 25px 0px;text-align: center;color: #2E6AB1;overflow: hidden;}
.pager a{border:1px solid #9AAFE5;color:#2E6AB1;margin:0px 5px;padding:5px 8px;text-decoration: none;}
.pager a.hover,.pager a.active{background-color:#2E6AB1;border-color:#000080;color:#FFF;}
.pager a.disabled{color:#C8CDD2;cursor:auto;}

$(".div1").pagination({
   count:200,
   size:10,
   index:1,
   lrCount:3,
   lCount:1,
   rCount:1,     
   callback:function(options){
     //alert(options.index);     
     //options.count = 300;
     //return options;
   },
   beforeRender:function(jA){
     //jA.attr("href","default.aspx?index="+jA.text());
   }  
 });