Jquery 插件入门

  网上一搜各种插件，什么文件上传，图片浏览 ，Autocomplete等

这些插件，源代码，新手看起来是很吃力的，当然我也是新手，我开始改AutoComplete这个插件一点点，却真不知道如何开始，后面就用Firefox的fireDebug慢慢看。

我也不是专门做前端的，但是总得了解，基本的使用还是得会。

今天，来总结下，最近看的插件的基础知识，这里算个入门，希望能帮到新手党们。

下面是2个非常重要的扩展函数。

$.extend  and $.fn.extend

$.extend(object) 可以理解为JQuery 添加一个静态方法。

$.fn.extend(object) 可以理解为JQuery实例添加一个方法。

基本的定义与调用：

/* $.extend 定义与调用
 */
$.extend({ fun1: function () { alert("执行方法一"); } });
$.fun1();
/*  $.fn.extend 定义与调用
 */
$.fn.extend({ fun2: function () { alert("执行方法2"); } });
$(this).fun2();
//等同于
$.fn.fun3 = function () { alert("执行方法三"); }
$(this).fun3();

  $.extend(target, [object1], [objectN]) 还有个用法,就是合并到第一个object.

该方法主要用于合并两个或更多对象的内容(属性)到第一个对象，并返回合并后的第一对象。如果该方法只有一个参数target，则该参数将扩展jQuery的命名空间，即作为静态方法挂在jQuery全局对象下，如jQuery里的$.ajax、$.getJSON全局函数等，如前面看到的：

值得注意的是：多个对象参数合并时，会破坏第一个对象的结构，所以可传递一个空对象作为第一个参数，如：$.extend({}, object1, object2);

 var options = $.extend({},defaults, options);

上面代码就是合并到{}中，然后赋值到options。这个在写插件的时候经常使用，用户可以自己定义某些属性，

插件一般也会定义默认属性，调用上面方法后，如果自定义属性，这使用新属性，否则，则使用默认属性，这个是非常有用的。

$.fn.extend(target)

在jQuery中，$.fn本质上是等于jQuery的原型，即$.fn = $.prototype， 所以该方法实际上是为jQuery原型添加方法，即把target对象的方法添加到jQuery原型中去，这样jQuery对象实例就可以访问添加的方法了，这也是jQuery插件开发常用的方法，特别是添加多个接口时。如：

// 将hello、hello2方法添加到jquery原型中
$.fn.extend({ 
    hello: function() {alert("hello!");},
    hello2: function() {alert("hello again!);}
});

看看Autocomplete插件使用的该方法。

$.fn.extend({
    autocomplete: function(urlOrData, options) {
        var isUrl = typeof urlOrData == "string";
        options = $.extend({}, $.Autocompleter.defaults, {
            url: isUrl ? urlOrData : null,
            data: isUrl ? null : urlOrData,
            delay: isUrl ? $.Autocompleter.defaults.delay : 10
            max: options && !options.scroll ? 1000 : 15000
        }, options);
        
        // if highlight is set to false, replace it with a do-nothing function
        options.highlight = options.highlight || function(value) { return value; };
        
        // if the formatMatch option is not specified, then use formatItem for backwards compatibility
        options.formatMatch = options.formatMatch || options.formatItem;
        
        return this.each(function() {
            new $.Autocompleter(this, options);
        });
    },
    result: function(handler) {
        return this.bind("result", handler);
    },
    search: function(handler) {
        return this.trigger("search", [handler]);
    },
    flushCache: function() {
        return this.trigger("flushCache");
    },
    setOptions: function(options){
        return this.trigger("setOptions", [options]);
    },
    unautocomplete: function() {
        return this.trigger("unautocomplete");
    }
});

看不懂？没关系，下面马来接上。

如果添加单个方法到jQuery原型中，可使用$.fn.pluginName方法添加，如：

// 将hello方法添加到jquery原型中
$.fn.hello = function() {
    // ...            
};

　　

插件通用模板（单个方法）：

插件有自己的基本格式：

;(function($){
    $.fn.yourName = function(options){
        //各种属性、参数
        }
        var options = $.extend(defaults, options);
        return this.each(function(){
        //插件实现代码
        });
    };
})(jQuery);

 上面代码的最前面有一个分号，这是为了防止多个脚本文件合并时，其他脚本的结尾语句没有添加分号，造成运行时错误。

1、把全部代码放在闭包(一个即时执行函数)里

此时闭包相当于一个私有作用域，外部无法访问到内部的信息，并且不会存在全局变量的污染情况。官方创建开发规范的解释是：

a) 避免全局依赖；

b) 避免第三方破坏；

c) 兼容jQuery操作符'$'和'jQuery '。

如下所示：

(function($) {
    // 局部作用域中使用$来引用jQuery
    // ...
})(jQuery);

这段代码在被解析时可理解成以下代码：

var jQ = function($) {
  // code goes here
}; 
jQ(jQuery);

新手如果无法理解，你知道，这是官方标准就ok。

下面是这个美化表格的例子，实现原理倒是简单，无非就是找到表格的奇偶行，然后添加不同的class，活动行高亮显示也很简单，只要判断mouseover事件，然后添加一个class，mouseout的时候，再去掉这个class即可。

查看这个链接能看到详细，你可以查看具体看看，写的不错，特别是步骤很清晰。

http://www.cnblogs.com/JustinYoung/archive/2010/03/30/jquery-chajian.html

好，基本框架晓得了，下面就是填充具体内容了。

(function($){
    $.fn.tableUI = function(options){
        var defaults = {
            evenRowClass:"evenRow",
            oddRowClass:"oddRow",
            activeRowClass:"activeRow"            
        }
        var options = $.extend({},defaults, options);
        this.each(function(){
            //实现代码
        });
    };
})(jQuery);

重复一句：

var options = $.extend({}，defaults, options);

其实就是合并多个对象为一个。这里就是，如果你在调用的时候写了新的参数，就用你新的参数，如果没有写，就用默认的参数。想进一步了解的朋友，可以参考jquery的官方文档： http://api.jquery.com/jQuery.extend/

其实，这里定义默认 var defaults是不规则的写法，

规则该是这样

$.fn.TableUI.defaults={    
  evenRowCass: "evenRow", 
  oddRowClass: "oddRow",
  activeRowClass: "activeRow"
};

options = $.extend({},$.fn.TableUI.defaults,options);

　　

好了，直接看全部代码：

//这里最好写上相关描述，如时间，作者，主要用于干什么

/*

 * tableUI 0.1

 * Copyright (c) 2009 JustinYoung  http://justinyoung.cnblogs.com/

 * Date: 2010-03-30

 * 使用tableUI可以方便地将表格提示使用体验。先提供的功能有奇偶行颜色交替，鼠标移上高亮显示

 */

;(function($){
    $.fn.tableUI = function(options){

　　$.fn.TableUI.defaults={
　　　　evenRowCass: "evenRow",
　　　　oddRowClass: "oddRow",
　　　　activeRowClass: "activeRow"
　　};

       var options = $.extend({},　$.fn.TableUI.defaults, options); //合并
        return this.each(function(){
            var thisTable=$(this);
            //添加奇偶行颜色
            $(thisTable).find("tr:even").addClass(options.evenRowClass);
            $(thisTable).find("tr:odd").addClass(options.oddRowClass);
            //添加活动行颜色
            $(thisTable).find("tr").bind("mouseover",function(){
                $(this).addClass(options.activeRowClass);
            });
            $(thisTable).find("tr").bind("mouseout",function(){
                $(this).removeClass(options.activeRowClass);
            });
        });
    };
})(jQuery);

效果就是下面这个效果，当然会有点不一样，因为我自己重新定义了css样式.：

http://downloads.cnblogs.com/justinyoung/articleIMG/2010/tableUI/index.html

下面是调用代码。

 <script src="Scripts/jquery-1.4.1.min.js" type="text/javascript"></script>
    <script src="Scripts/TableUI.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(document).ready(function () {
            $(".table_solid").TableUI({ evenRowCass: "eventRow", oddRowClass: "oddRowClass", activeRowClass: "activeRow" }); //这里是输入新的参数，不使用默认参数。插件代码会自动覆盖。
        })
    </script>
    <style type="text/css">
        body
        {
            font-family: 'Verdana' , '宋体';
            font-size: 12px;
        }
        .eventRow
        {
            background-color: #f0f0ff;
        }
        .activeRow
        {
            background-color: #FFFF55;
        }
        .oddRowClass
        {
            background-color: red;
        }
    </style>

在看下面的代码时，涉及到模式，这里介绍两个常用的模式，

单例模式

<script>
      /*
      * Here’s the setup function which populates an array with integers
      */
      var myApp = {
          init: function (obj) {
              //code to intialize your application    
              alert("init: " + obj);
          },
          dashboard: function () {
              //your dashboard feature goes here
              alert("dashboard");
          },
          controlPanel: function () {
              //control panel code goes here
              alert("controlPanel");
          },
          appSettings: function () {
              //code that updates settings goes here
              alert("appSettings");
          }
      }
      //kick it off with ready()
      $(function () {
          myApp.init("test");
          myApp.dashboard();
          myApp.controlPanel();
          myApp.appSettings();
      });

</script>

使用应用程序名称空间，可以极大地降低变量名冲突的可能性

模块模式

模块模式主要包含三个主要的组件：一个与前面类似的名称空间，一个立即执行函数和函数返回的对象。

该返回对象包含了共有方法和共有属性。

<script type="text/javascript">
    //Our app namespace. We pass in the jQuery object to shorten lookups
      var myApp = function ($) {   //立即执行函数 
          // private variables and methods, only available within this myApp  //私有变量和方法
          var message = "not directly accessible from outside the module";
          function multiplier(x, y) {
              return x * y
          };
          //the return object contains the public   函数的返回对象
          //properties and public methods 
          return {
              init: function () {
                  //intialize the app
                  alert("return init");
              },
              prop: "42",
              specialNumber: function () {
                  //access to our private method  访问私有方法
                  var num = multiplier(7, 6);
                  return "Our special number is definitely " + num;
              },
              //we provide controlled access to private variables
              shareMessage: function (arg) {
                  if (arg === "open sesame") {
                      return message + ",unless you know the magic word";
                  } else {
                      throw new Error("You need to know the magic word");

                  }
              }
          };
      } (jQuery);

      myApp.dashboard = function ($) {
          // private variables and methods
          var config = {
              "color": "blue",
              "title": "my dashboard",
              "width": "960px"
          };
          return {
              init: function () {
                  //intialize the dashboard
              },
              //updateConfig allows for monitored configuration 
              //of the private config object
              updateConfig: function (obj) {

                  if ($.inArray(obj.color, ["red", "blue", "green", "purple"] !== -1)) {
                      config.color = obj.color;
                  }
                  config.title = obj.title || config.title;
                  config.width = obj.width || config.width;

              },
              render: function () {
                  //renders the dashboard
                  var $dashboard = $("<div/>").html("<h1/>")
                  $dashboard.text(config.title)
           .css(
             { "width": config.width,
                 "color": config.color
             }
           );
                  $("#main").append($dashboard);
              }
          };
      } (jQuery);


  console.log("message:" + myApp.message )　　//undefined
  
  console.log("multiplier" +  myApp.multiplier() )
 
  console.log("shareMessage :"+ myApp.shareMessage( "please?" ) )
  
  console.log( myApp.shareMessage( "open sesame" ) )

  console.log( myApp.prop );
  
  console.log( myApp.specialNumber() );
  
</script>

 多看一个实例

 <script type="text/javascript">
          var blogModule = (function () {
              var my = {}, privateName = "博客园";

              function privateAddTopic(data) {
                  // 这里是内部处理代码
              }

              my.Name = privateName;
              my.AddTopic = function (data) {
                  privateAddTopic(data);
              };

              return my;
          } ()); //我们可以在最后一个}后面加上一个括号()，来达到自执行的目的，这样该实例在内存中只会存在一份copy
          //注意，匿名函数后面的括号，这是JavaScript语言所要求的，因为如果你不声明的话，
          //JavaScript解释器默认是声明一个function函数，有括号，就是创建一个函数表达式，也就是自执行，用的时候不用和上面那样在new了，
          //当然你也可以这样来声明：

          blogModule.AddTopic('test');

          var jspy = (function () {
              //首先我们创造一个_count变量，下划线表明它是一个私有变量。在Javascript中下划线并没有什么实际的意义，
              //但是它是一个用来标明私有变量的普遍用法。现在函数就可以操纵、返回变量了：
              var _count = 0;

              var incrementCount = function () {
                  _count++;
              };

              var getCount = function () {
                  return _count;
              };

              return {
                  Add: incrementCount,
                  Get: getCount
              };


          })();
          jspy.Add();
          alert(jspy.Get())

      //app的名称空间，传入jQuery对象以缩短查找过程
          var myApp = function ( $ ) {
              //私有变量和方法，仅在该myApp中可用
              var message = "not directly accessible from outside the module";
              function multiplier(x, y) {
                  return x * y;
              };

              //返回对象包含了公有属性和公有方法
              return {
                  init: function () {
                      //初始化app
                      alert("初始化app");
                  },
                  prop: "42",
                  specialNumber: function () {
                      //访问私有方法
                      var num = multiplier(7, 6);
                      return "our special number is definitly " + num;
                  },
                  //对私有变量的提供有控制的访问
                  shareMessage: function (arg) {
                      if (arg === "open sesame") {
                          return message + ", unless you know the magic word";
                      }
                      else {
                         return ("You need to know the magic word");
                      }
                  }

             };
          }(jQuery);

          console.log("access message in myApp:" + myApp.message); //undefined
          console.log("call init in return:" + myApp.init()); //
         // console.log("call multiplier:" + myApp.multiplier(2, 3)); //throw exception Object doesn't support property or method 'multiplier'
          console.log("share message in return " + myApp.shareMessage()) //it's ok
          console.log("share arg message in return " + myApp.shareMessage("open sesame")) //it's ok
          console.log("show prop in return :" + myApp.prop); //it's work
          console.log("show specialNumber in return :" + myApp.specialNumber()); //it's work
      </script>

在控制台中测试该实例app,在模块内，可以引用私有变量，但是在模块之外，无法直接调用私有变量

附加自动完成组件源代码

/*
 * Autocomplete - jQuery plugin 1.1pre
 *
 * Copyright (c) 2007 Dylan Verheul, Dan G. Switzer, Anjesh Tuladhar, Jörn Zaefferer
 *
 * Dual licensed under the MIT and GPL licenses:
 *   http://www.opensource.org/licenses/mit-license.php
 *   http://www.gnu.org/licenses/gpl.html
 *
 * Revision: $Id: jquery.autocomplete.js 5785 2008-07-12 10:37:33Z joern.zaefferer $
 */

;(function($) {
    
$.fn.extend({
    autocomplete: function(urlOrData, options) {
        var isUrl = typeof urlOrData == "string";
        options = $.extend({}, $.Autocompleter.defaults, {
            url: isUrl ? urlOrData : null,
            data: isUrl ? null : urlOrData,
            delay: isUrl ? $.Autocompleter.defaults.delay : 0,
            max: options && !options.scroll ? 9999999 : 9999999
        }, options);
        
        // if highlight is set to false, replace it with a do-nothing function
        options.highlight = options.highlight || function(value) { return value; };
        
        // if the formatMatch option is not specified, then use formatItem for backwards compatibility
        options.formatMatch = options.formatMatch || options.formatItem;
        
        return this.each(function() {
            new $.Autocompleter(this, options);
        });
    },
    result: function(handler) {
        return this.bind("result", handler);
    },
    search: function(handler) {
        return this.trigger("search", [handler]);
    },
    flushCache: function() {
        return this.trigger("flushCache");
    },
    setOptions: function(options){
        return this.trigger("setOptions", [options]);
    },
    unautocomplete: function() {
        return this.trigger("unautocomplete");
    }
});

$.Autocompleter = function(input, options) {

    var NO_DATA_FOUND = "No Data Found";
    
    var KEY = {
        UP: 38,
        DOWN: 40,
        DEL: 46,
        TAB: 9,
        RETURN: 13,
        ESC: 27,
        COMMA: 188,
        PAGEUP: 33,
        PAGEDOWN: 34,
        BACKSPACE: 8
    };

    // Create $ object for input element
    var $input = $(input).attr("autocomplete", "off").addClass(options.inputClass);

    var timeout;
    var previousValue = "";
    var cache = $.Autocompleter.Cache(options);
    var hasFocus = 0;
    var lastKeyPressCode;
    var config = {
        mouseDownOnSelect: false
    };
    var select = $.Autocompleter.Select(options, input, selectCurrent, config);
    
    var blockSubmit;
    
    // prevent form submit in opera when selecting with return key
    $.browser.opera && $(input.form).bind("submit.autocomplete", function() {
        if (blockSubmit) {
            blockSubmit = false;
            return false;
        }
    });
    
    // only opera doesn't trigger keydown multiple times while pressed, others don't work with keypress at all
    $input.bind(($.browser.opera ? "keypress" : "keydown") + ".autocomplete", function(event) {
        // track last key pressed
        lastKeyPressCode = event.keyCode;
        switch(event.keyCode) {
            case KEY.UP:
                event.preventDefault();
                if ( select.visible() ) {
                    select.prev();
                } else {
                    onChange(0, true);
                }
                break;
            case KEY.DOWN:
                event.preventDefault();
                if ( select.visible() ) {
                    select.next();
                } else {
                    onChange(0, true);
                }
                break;
                
            case KEY.PAGEUP:
                event.preventDefault();
                if ( select.visible() ) {
                    select.pageUp();
                } else {
                    onChange(0, true);
                }
                break;
                
            case KEY.PAGEDOWN:
                event.preventDefault();
                if ( select.visible() ) {
                    select.pageDown();
                } else {
                    onChange(0, true);
                }
                break;
            
            // matches also semicolon
            case options.multiple && $.trim(options.multipleSeparator) == "," && KEY.COMMA:
            case KEY.TAB:
            case KEY.RETURN:
                if( selectCurrent() ) {
                    // stop default to prevent a form submit, Opera needs special handling
                    event.preventDefault();
                    blockSubmit = true;
                    return false;
                }
                break;
                
            case KEY.ESC:
                select.hide();
                break;
                
            default:
                clearTimeout(timeout);
                timeout = setTimeout(onChange, options.delay);
                break;
        }
    }).focus(function(){
        // track whether the field has focus, we shouldn't process any
        // results if the field no longer has focus
        hasFocus++;
    }).blur(function() {
        hasFocus = 0;
        if (!config.mouseDownOnSelect) {
            hideResults();
        }
    }).click(function() {
        // show select when clicking in a focused field
        if ( hasFocus++ > 1 && !select.visible() ) {
            onChange(0, true);
        }
    }).bind("search", function() {
        // TODO why not just specifying both arguments?
        var fn = (arguments.length > 1) ? arguments[1] : null;
        function findValueCallback(q, data) {
            var result;
            if( data && data.length ) {
                for (var i=0; i < data.length; i++) {
                    if( data[i].result.toLowerCase() == q.toLowerCase() ) {
                        result = data[i];
                        break;
                    }
                }
            }
            if( typeof fn == "function" ) fn(result);
            else $input.trigger("result", result && [result.data, result.value]);
        }
        $.each(trimWords($input.val()), function(i, value) {
            request(value, findValueCallback, findValueCallback);
        });
    }).bind("flushCache", function() {
        cache.flush();
    }).bind("setOptions", function() {
        $.extend(options, arguments[1]);
        // if we've updated the data, repopulate
        if ( "data" in arguments[1] )
            cache.populate();
    }).bind("unautocomplete", function() {
        select.unbind();
        $input.unbind();
        $(input.form).unbind(".autocomplete");
    });
    
    
    function selectCurrent() {
        var selected = select.selected();
        if( !selected )
            return false;
        
        var v = selected.result;
        previousValue = v;
        
        if ( options.multiple ) {
            var words = trimWords($input.val());
            if ( words.length > 1 ) {
                v = words.slice(0, words.length - 1).join( options.multipleSeparator ) + options.multipleSeparator + v;
            }
            v += options.multipleSeparator;
        }
        if(v === NO_DATA_FOUND) v = "";
        $input.val(v);
        hideResultsNow();
        $input.trigger("result", [selected.data, selected.value]);
        return true;
    }
    
    function onChange(crap, skipPrevCheck) {
        if( lastKeyPressCode == KEY.DEL ) {
            select.hide();
            return;
        }
        
        var currentValue = $input.val();
        
        if ( !skipPrevCheck && currentValue == previousValue )
            return;
        
        previousValue = currentValue;
        
        currentValue = lastWord(currentValue);
        if ( currentValue.length >= options.minChars) {
            $input.addClass(options.loadingClass);
            if (!options.matchCase)
                currentValue = currentValue.toLowerCase();
            request(currentValue, receiveData, hideResultsNow);
        } else {
            stopLoading();
            select.hide();
        }
    };
    
    function trimWords(value) {
        if ( !value ) {
            return [""];
        }
        var words = value.split( options.multipleSeparator );
        var result = [];
        $.each(words, function(i, value) {
            if ( $.trim(value) )
                result[i] = $.trim(value);
        });
        return result;
    }
    
    function lastWord(value) {
        if ( !options.multiple )
            return value;
        var words = trimWords(value);
        return words[words.length - 1];
    }
    
    // fills in the input box w/the first match (assumed to be the best match)
    // q: the term entered
    // sValue: the first matching result
    function autoFill(q, sValue){
        // autofill in the complete box w/the first match as long as the user hasn't entered in more data
        // if the last user key pressed was backspace, don't autofill
        if( options.autoFill && (lastWord($input.val()).toLowerCase() == q.toLowerCase()) && lastKeyPressCode != KEY.BACKSPACE ) {
            // fill in the value (keep the case the user has typed)
            $input.val($input.val() + sValue.substring(lastWord(previousValue).length));
            // select the portion of the value not typed by the user (so the next character will erase)
            $.Autocompleter.Selection(input, previousValue.length, previousValue.length + sValue.length);
        }
    };

    function hideResults() {
        clearTimeout(timeout);
        timeout = setTimeout(hideResultsNow, 200);
    };

    function hideResultsNow() {
        var wasVisible = select.visible();
        select.hide();
        clearTimeout(timeout);
        stopLoading();
        if (options.mustMatch) {
            // call search and run callback
            $input.search(
                function (result){
                    // if no value found, clear the input box
                    if( !result ) {
                        if (options.multiple) {
                            var words = trimWords($input.val()).slice(0, -1);
                            $input.val( words.join(options.multipleSeparator) + (words.length ? options.multipleSeparator : "") );
                        }
                        else
                            $input.val( "" );
                    }
                }
            );
        }
        if (wasVisible)
            // position cursor at end of input field
            $.Autocompleter.Selection(input, input.value.length, input.value.length);
    };

    function receiveData(q, data) {
        if ( data && data.length && hasFocus ) {
            stopLoading();
            select.display(data, q);
            autoFill(q, data[0].value);
            select.show();
        } else {
            hideResultsNow();
        }
    };

    function request(term, success, failure) {
        if (!options.matchCase)
            term = term.toLowerCase();
        var data = cache.load(term);
        // recieve the cached data
        if (data && data.length) {
            success(term, data);
        // if an AJAX url has been supplied, try loading the data now
        } else if( (typeof options.url == "string") && (options.url.length > 0) ){
            
            var extraParams = {
                timestamp: +new Date()
            };
            $.each(options.extraParams, function(key, param) {
                extraParams[key] = typeof param == "function" ? param() : param;
            });
            
            $.ajax({
                // try to leverage ajaxQueue plugin to abort previous requests
                mode: "abort",
                // limit abortion to this input
                port: "autocomplete" + input.name,
                dataType: options.dataType,
                url: options.url,
                data: $.extend({
                    q: lastWord(term),
                    limit: options.max
                }, extraParams),
                success: function(data) {
                    //added by lideng ,for if don't find data ,then assign 'No data found' to control
                    if(!data) data = NO_DATA_FOUND;//alert('No data found');
                    var parsed = options.parse && options.parse(data) || parse(data);
                    cache.add(term, parsed);
                    success(term, parsed);
                }
            });
        } else {
            // if we have a failure, we need to empty the list -- this prevents the the [TAB] key from selecting the last successful match
            select.emptyList();
            failure(term);
        }
    };
    
    function parse(data) {
        var parsed = [];
        var rows = data.split("
");
        for (var i=0; i < rows.length; i++) {
            var row = $.trim(rows[i]);
            if (row) {
                row = row.split("|");
                parsed[parsed.length] = {
                    data: row,
                    value: row[0],
                    result: options.formatResult && options.formatResult(row, row[0]) || row[0]
                };
            }
        }
        return parsed;
    };

    function stopLoading() {
        $input.removeClass(options.loadingClass);
    };

};

$.Autocompleter.defaults = {
    inputClass: "ac_input",
    resultsClass: "ac_results",
    loadingClass: "ac_loading",
    minChars: 1,
    //delay: 400,
    delay: 0, 
    matchCase: false,
    //matchSubset: true,
    matchSubset: false,
    matchContains: false,
    cacheLength: 10,
    max: 100,
    mustMatch: false,
    extraParams: {},
    selectFirst: true,
    formatItem: function(row) { return row[0]; },
    formatMatch: null,
    autoFill: false,
     0,
    multiple: false,
    multipleSeparator: ", ",
    highlight: function(value, term) {
        return value.replace(new RegExp("(?![^&;]+;)(?!<[^<>]*)(" + term.replace(/([^$()[]{}*.+?|\])/gi, "\$1") + ")(?![^<>]*>)(?![^&;]+;)", "gi"), "<strong>$1</strong>");
    },
    scroll: true,
    scrollHeight: 180
};

$.Autocompleter.Cache = function(options) {

    var data = {};
    var length = 0;
    
    function matchSubset(s, sub) {
        if (!options.matchCase) 
            s = s.toLowerCase();
        var i = s.indexOf(sub);
        if (options.matchContains == "word"){
            i = s.toLowerCase().search("\b" + sub.toLowerCase());
        }
        if (i == -1) return false;
        return i == 0 || options.matchContains;
    };
    
    function add(q, value) {
        if (length > options.cacheLength){
            flush();
        }
        if (!data[q]){ 
            length++;
        }
        data[q] = value;
    }
    
    function populate(){
        if( !options.data ) return false;
        // track the matches
        var stMatchSets = {},
            nullData = 0;

        // no url was specified, we need to adjust the cache length to make sure it fits the local data store
        if( !options.url ) options.cacheLength = 1;
        
        // track all options for minChars = 0
        stMatchSets[""] = [];
        
        // loop through the array and create a lookup structure
        for ( var i = 0, ol = options.data.length; i < ol; i++ ) {
            var rawValue = options.data[i];
            // if rawValue is a string, make an array otherwise just reference the array
            rawValue = (typeof rawValue == "string") ? [rawValue] : rawValue;
            
            var value = options.formatMatch(rawValue, i+1, options.data.length);
            if ( value === false )
                continue;
                
            var firstChar = value.charAt(0).toLowerCase();
            // if no lookup array for this character exists, look it up now
            if( !stMatchSets[firstChar] ) 
                stMatchSets[firstChar] = [];

            // if the match is a string
            var row = {
                value: value,
                data: rawValue,
                result: options.formatResult && options.formatResult(rawValue) || value
            };
            
            // push the current match into the set list
            stMatchSets[firstChar].push(row);

            // keep track of minChars zero items
            if ( nullData++ < options.max ) {
                stMatchSets[""].push(row);
            }
        };

        // add the data items to the cache
        $.each(stMatchSets, function(i, value) {
            // increase the cache size
            options.cacheLength++;
            // add to the cache
            add(i, value);
        });
    }
    
    // populate any existing data
    setTimeout(populate, 25);
    
    function flush(){
        data = {};
        length = 0;
    }
    
    return {
        flush: flush,
        add: add,
        populate: populate,
        load: function(q) {
            if (!options.cacheLength || !length)
                return null;
            /* 
             * if dealing w/local data and matchContains than we must make sure
             * to loop through all the data collections looking for matches
             */
            if( !options.url && options.matchContains ){
                // track all matches
                var csub = [];
                // loop through all the data grids for matches
                for( var k in data ){
                    // don't search through the stMatchSets[""] (minChars: 0) cache
                    // this prevents duplicates
                    if( k.length > 0 ){
                        var c = data[k];
                        $.each(c, function(i, x) {
                            // if we've got a match, add it to the array
                            if (matchSubset(x.value, q)) {
                                csub.push(x);
                            }
                        });
                    }
                }                
                return csub;
            } else 
            // if the exact item exists, use it
            if (data[q]){
                return data[q];
            } else
            if (options.matchSubset) {
                for (var i = q.length - 1; i >= options.minChars; i--) {
                    var c = data[q.substr(0, i)];
                    if (c) {
                        var csub = [];
                        $.each(c, function(i, x) {
                            if (matchSubset(x.value, q)) {
                                csub[csub.length] = x;
                            }
                        });
                        return csub;
                    }
                }
            }
            return null;
        }
    };
};

$.Autocompleter.Select = function (options, input, select, config) {
    var CLASSES = {
        ACTIVE: "ac_over"
    };
    
    var listItems,
        active = -1,
        data,
        term = "",
        needsInit = true,
        element,
        list;
    
    // Create results
    function init() {
        if (!needsInit)
            return;
        element = $("<div/>")
        .hide()
        .addClass(options.resultsClass)
        .css("position", "absolute")
        .appendTo(document.body);
    
        list = $("<ul/>").appendTo(element).mouseover( function(event) {
            if(target(event).nodeName && target(event).nodeName.toUpperCase() == 'LI') {
                active = $("li", list).removeClass(CLASSES.ACTIVE).index(target(event));
                $(target(event)).addClass(CLASSES.ACTIVE);            
            }
        }).click(function(event) {
            $(target(event)).addClass(CLASSES.ACTIVE);
            select();
            // TODO provide option to avoid setting focus again after selection? useful for cleanup-on-focus
            input.focus();
            return false;
        }).mousedown(function() {
            config.mouseDownOnSelect = true;
        }).mouseup(function() {
            config.mouseDownOnSelect = false;
        });
        
        if( options.width > 0 )
            element.css("width", options.width);
            
        needsInit = false;
    } 
    
    function target(event) {
        var element = event.target;
        while(element && element.tagName != "LI")
            element = element.parentNode;
        // more fun with IE, sometimes event.target is empty, just ignore it then
        if(!element)
            return [];
        return element;
    }

    function moveSelect(step) {
        listItems.slice(active, active + 1).removeClass(CLASSES.ACTIVE);
        movePosition(step);
        var activeItem = listItems.slice(active, active + 1).addClass(CLASSES.ACTIVE);
        if(options.scroll) {
            var offset = 0;
            listItems.slice(0, active).each(function() {
                offset += this.offsetHeight;
            });
            if((offset + activeItem[0].offsetHeight - list.scrollTop()) > list[0].clientHeight) {
                list.scrollTop(offset + activeItem[0].offsetHeight - list.innerHeight());
            } else if(offset < list.scrollTop()) {
                list.scrollTop(offset);
            }
        }
    };
    
    function movePosition(step) {
        active += step;
        if (active < 0) {
            active = listItems.size() - 1;
        } else if (active >= listItems.size()) {
            active = 0;
        }
    }
    
    function limitNumberOfItems(available) {
        return options.max && options.max < available
            ? options.max
            : available;
    }
    
    function fillList() {
        list.empty();
        var max = limitNumberOfItems(data.length);
        for (var i=0; i < max; i++) {
            if (!data[i])
                continue;
            var formatted = options.formatItem(data[i].data, i+1, max, data[i].value, term);
            if ( formatted === false )
                continue;
            var li = $("<li/>").html( options.highlight(formatted, term) ).addClass(i%2 == 0 ? "ac_even" : "ac_odd").appendTo(list)[0];
            $.data(li, "ac_data", data[i]);
        }
        listItems = list.find("li");
        if ( options.selectFirst ) {
            listItems.slice(0, 1).addClass(CLASSES.ACTIVE);
            active = 0;
        }
        // apply bgiframe if available
        if ( $.fn.bgiframe )
            list.bgiframe();
    }
    
    return {
        display: function(d, q) {
            init();
            data = d;
            term = q;
            fillList();
        },
        next: function() {
            moveSelect(1);
        },
        prev: function() {
            moveSelect(-1);
        },
        pageUp: function() {
            if (active != 0 && active - 8 < 0) {
                moveSelect( -active );
            } else {
                moveSelect(-8);
            }
        },
        pageDown: function() {
            if (active != listItems.size() - 1 && active + 8 > listItems.size()) {
                moveSelect( listItems.size() - 1 - active );
            } else {
                moveSelect(8);
            }
        },
        hide: function() {
            element && element.hide();
            listItems && listItems.removeClass(CLASSES.ACTIVE);
            active = -1;
        },
        visible : function() {
            return element && element.is(":visible");
        },
        current: function() {
            return this.visible() && (listItems.filter("." + CLASSES.ACTIVE)[0] || options.selectFirst && listItems[0]);
        },
        show: function() {
            var offset = $(input).offset();
            element.css({
                 typeof options.width == "string" || options.width > 0 ? options.width : $(input).width(),
                top: offset.top + input.offsetHeight,
                left: offset.left
            }).show();
            if(options.scroll) {
                list.scrollTop(0);
                list.css({
                    maxHeight: options.scrollHeight,
                    overflow: 'auto'
                });
                
                if($.browser.msie && ((typeof document.body.style.maxHeight === "undefined") || (document.body.style.maxHeight == ''))) {
                //if($.browser.msie && ((typeof document.body.style.maxHeight === "undefined"))) {
                    var listHeight = 0;
                    listItems.each(function() {
                        listHeight += this.offsetHeight;
                    });
                    var scrollbarsVisible = listHeight > options.scrollHeight;
                    list.css('height', scrollbarsVisible ? options.scrollHeight : listHeight );
//                    if (!scrollbarsVisible) {
//                        // IE doesn't recalculate width when scrollbar disappears
//                        listItems.width( list.width() - parseInt(listItems.css("padding-left")) - parseInt(listItems.css("padding-right")) );
//                    }
                }
                
            }
        },
        selected: function() {
            var selected = listItems && listItems.filter("." + CLASSES.ACTIVE).removeClass(CLASSES.ACTIVE);
            return selected && selected.length && $.data(selected[0], "ac_data");
        },
        emptyList: function (){
            list && list.empty();
        },
        unbind: function() {
            element && element.remove();
        }
    };
};

$.Autocompleter.Selection = function(field, start, end) {
    if( field.createTextRange ){
        var selRange = field.createTextRange();
        selRange.collapse(true);
        selRange.moveStart("character", start);
        selRange.moveEnd("character", end);
        selRange.select();
    } else if( field.setSelectionRange ){
        field.setSelectionRange(start, end);
    } else {
        if( field.selectionStart ){
            field.selectionStart = start;
            field.selectionEnd = end;
        }
    }
    field.focus();
};

})(jQuery);

简单实现在这里了，欢迎交流学习