[转载]Prototype之详细解说[转] – Sam Lin – 博客园

mikel
JavaScript
2014-12-17
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[转载]Prototype之详细解说[转] - Sam Lin - 博客园.
[js]
/* Prototype JavaScript framework, version 1.4.0

* Prototype is freely distributable under the terms of an MIT-style license.

* For details, see the Prototype web site: http://prototype.conio.net/

* 这是一个JavaScript的框架,致力于简化动态的Web开发，完全按照面对对象的思想

* 进行Javascript开发，添加了迭代器的概念增强Javascript的设计能力。

* Prototype框架构思独特充满了技巧性的代码，方便易用的工具类！

/*--------------------------------------------------------------------------*/

/* 【Prototype】定义一个全局对象,提供一个全局的基本信息和工具 */

var Prototype = {

Version: '1.4.0', //可以作为版本检测用

//用于脚本检测的正则表达式，经常使用所以放在这里起到全局常量的作用

ScriptFragment: '(?:<script.*?>)(( | |.)*?)(?:</script>)',

emptyFunction: function() {},//空函数

K: function(x) {return x}//K方法返回参数本身，在后面经常用到

}

/*========================================================================================*/

*【Class】对象的作用只有一个就是提供了一个定义类的模式

* 仅含有create 一个方法，返回一个构造函数。

* 一般使用如下

* var X = Class.create(); 返回一个类型

* 要使用 X 类型，需继续用 new X()来获取一个实例这与C# JAVA类似

* 返回的构造函数会执行名为 initialize 的方法， initialize 是 Ruby 对象的构造器方法名字。

* 此时initialize方法还没有定义，其后的代码中创建新类型时会建立相应的同名方法,可以看作是一个抽象方法。

* 从C#角度讲可以理解为用Class.create()创建一个继承Object基类的类。

var Class = {

create: function() {

return function() { //下面使用Apply方法传递参数是一个常用的技巧

this.initialize.apply(this, arguments);

}

/*========================================================================================*/

//Abstract是一个空对象，它的作用仅仅是作为一个抽象的命名空间，所有在该对象下定义的类都是抽象类

//从而从形式上与实体类分开

var Abstract = new Object();

*Object是所有对象的基类，这个基类有两个静态方法

//把Source的所有属性和方法传递给Destination，实现了继承的效果

Object.extend = function(destination, source) {

for (property in source) {

destination[property] = source[property];

}

return destination;

}

//观察Object的组成，需要参数中的object实现自己的inspect方法

Object.inspect = function(object) {

try {

if (object == undefined) return 'undefined';

if (object == null) return 'null';

return object.inspect ? object.inspect() : object.toString();

} catch (e) {

if (e instanceof RangeError) return '';

throw e;

}

/*========================================================================================*/

//【Function】是所有函数对象的基类，可以通过对它的扩展实现对所有函数对象添加功能

/* 这里在绑定的时候旧可以传递参数而不是调用的时候才指定参数，bind方法接收多个参数

将函数绑定到第一个参数指定的对象上，并返回该方法的调用句柄

Function.prototype.bind = function() {

// $A()方法的作用是把参数专为数组

//数组的shift方法作用是删除数组的第一个元素

var __method = this, args = $A(arguments), object = args.shift();

return function() {

return __method.apply(object, args.concat($A(arguments)));

//这里的$A(arguments)是条用返回函数句柄时传递的参数，不是bind方法的参数

}

/**

* 和bind一样，不过这个方法一般用做html控件对象的事件处理。所以要传递event对象

* 好像是重载了_method方法

Function.prototype.bindAsEventListener = function(object) {

var __method = this;

return function(event) {

return __method.call(object, event || window.event);

}

/*========================================================================================*/

//【Function】是所有数值类型的基类

Object.extend(Number.prototype, {

toColorPart: function() { //RGB-》16进制颜色

var digits = this.toString(16);

if (this < 16) return '0' + digits;

return digits;

succ: function() { //数值加一 var a=1; var b=a.succ; 那么b=2

return this + 1;

times: function(iterator) {

//这里的参数iterator是一个迭代器作用就是循环调用指定次数的iterator函数

//$R(start,end,exclusive)是创建ObjectRnge对象的快捷方式

$R(0, this, true).each(iterator);

return this;

}

});

/*========================================================================================*/

//提供了一个方法these，要求参数是函数的句柄，可以有多个。作用就是返回第一个成功执行的函数的返回值

var Try = {

these: function() {

var returnValue;

for (var i = 0; i < arguments.length; i++) {

var lambda = arguments[i];

try {

returnValue = lambda();

break;

} catch (e) {}

}

return returnValue;

}

/*========================================================================================*/

//定时器类用来实现Window.setInterval的效果，在给定时间间隔执行某一个函数，增加了对重复执行的控制S

var PeriodicalExecuter = Class.create();

PeriodicalExecuter.prototype = {

initialize: function(callback, frequency) {

//构造函数指定回调函数和执行频率，单位是秒

this.callback = callback;

this.frequency = frequency;

this.currentlyExecuting = false;

this.registerCallback();

/* 开始调用定时器，无需显示调用，在构造函数中就实现了自动调用，这一下面的

this.onTimerEvent.bind(this)如果写成this.onTimerEvent则this指针就会指向widows对象即setInterval的默认对象

从而不能正确的引用到下面两个函数上，也就失去了对正在执行函数的控制

registerCallback: function() {

setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);

//下面的函数相当于是回调函数的一个代理， setInterval是到了指定的时间就会强制执行而这里

//加入了一个判断如果callback函数执行的时间超过了一个时间片，则阻止其被重复执行

onTimerEvent: function() {

if (!this.currentlyExecuting) {

try {

this.currentlyExecuting = true;

this.callback();

} finally {

this.currentlyExecuting = false;

}

/*使用举例：

function GetOnlineCount()

{//获得在线人数

}

new PeriodicalExecuter(GetOnlineCount,10)每10秒获取一次

/*========================================================================================*/

/* 框架核心内容--------【基础工具类】

/*========================================================================================*/

/*document.getElementById(id)获取一个指定ID的结点,是这个方法的快捷方式和扩展

可以指定多个参数返回一个对象数组。参数也不一定是ID也可以是对象本身的引用，例如

$('id')等价于$($('id'))

function $() {

var elements = new Array();

for (var i = 0; i < arguments.length; i++) {

var element = arguments[i];

if (typeof element == 'string')

element = document.getElementById(element);

if (arguments.length == 1)

return element;

elements.push(element);

}

return elements;

}

/*========================================================================================*/

//【String】类的扩展

//删除字符串中的HTML标记

Object.extend(String.prototype, {

stripTags: function() {

return this.replace(/</?[^>]+>/gi, '');

//删除字符串中的脚本块

stripScripts: function() {

return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');

//提取字符串中的所有脚本块，作为数组返回，每一个脚本作为一个数组元素

extractScripts: function() {

var matchAll = new RegExp(Prototype.ScriptFragment, 'img');

var matchOne = new RegExp(Prototype.ScriptFragment, 'im');

return (this.match(matchAll) || []).map(function(scriptTag) {

return (scriptTag.match(matchOne) || ['', ''])[1];

});

//提取字符串中的脚本并执行

evalScripts: function() {

return this.extractScripts().map(eval);

//将字符串进行html编码例如"<" --》"&lt"

escapeHTML: function() {

var div = document.createElement('div');

var text = document.createTextNode(this);

div.appendChild(text);

return div.innerHTML;

//对字符串进行html解码例如"&lt"--》"<"

unescapeHTML: function() {

var div = document.createElement('div');

div.innerHTML = this.stripTags();

return div.childNodes[0] ? div.childNodes[0].nodeValue : '';

//将查询字符串格式的字符串转换为键值对数组

//例如var s="a=1&b=2&c=3"; var s2=s.toQueryParams(); s2为{a:1,b:2,c:3}

toQueryParams: function() {

var pairs = this.match(/^??(.*)$/)[1].split('&');

return pairs.inject({}, function(params, pairString) {

var pair = pairString.split('=');

params[pair[0]] = pair[1];

return params;

});

//字符串转换为字符数组 "abc"-->['a','b','c']

toArray: function() {

return this.split('');

//连字符--》骆驼样式 'good-man'-->'goodMan'

camelize: function() {

var oStringList = this.split('-');

if (oStringList.length == 1) return oStringList[0];

var camelizedString = this.indexOf('-') == 0

? oStringList[0].charAt(0).toUpperCase() + oStringList[0].substring(1)

: oStringList[0];

for (var i = 1, len = oStringList.length; i < len; i++) {

var s = oStringList[i];

camelizedString += s.charAt(0).toUpperCase() + s.substring(1);

}

return camelizedString;

//得到字符串的组成结构

inspect: function() {

return "'" + this.replace('\', '\\').replace("'", '\'') + "'";

}

});

//定义了一个等价的函数

String.prototype.parseQuery = String.prototype.toQueryParams;

/*========================================================================================*/

//【Enumerable】可枚举接口是整个1.4.0框架的核心工具，所有实现此接口的类必须要实现_each(iterator)方法

var $break = new Object(); //首先定义了两个异常对象，用于进行迭代计算的控制

var $continue = new Object();

var Enumerable = {

//用于对对象的每一个元素遍历执行iterator迭代器函数

each: function(iterator) {

var index = 0; //可选参数表示元素在枚举对象的次序

try {

this._each(function(value) {//value是枚举元素的值

try {

iterator(value, index++);

} catch (e) {

if (e != $continue) throw e;

}

});

} catch (e) {

if (e != $break) throw e;

}

//判断是否所有的枚举元素都能使iterator返回true

all: function(iterator) {

var result = true;

this.each(function(value, index) {

result = result && !!(iterator || Prototype.K)(value, index);

if (!result) throw $break;

});

return result;

//判断是否有枚举元素能使iterator返回true，有一个就是True

any: function(iterator) {

var result = true;

this.each(function(value, index) {

if (result = !!(iterator || Prototype.K)(value, index))

throw $break;

});

return result;

//对所有的枚举元素执行iterator迭代器函数结果作为一个数组返回

collect: function(iterator) {

var results = [];

this.each(function(value, index) {

results.push(iterator(value, index));

});

return results;

//第一个素能使iterator返回true的枚举元素的值，没有返回undefined

detect: function (iterator) {

var result;

this.each(function(value, index) {

if (iterator(value, index)) {

result = value;

throw $break;

}

});

return result;

//找到所有的能使iterator迭代器函数返回true的枚举元素作为一个数组返回

findAll: function(iterator) {

var results = [];

this.each(function(value, index) {

if (iterator(value, index))

results.push(value);

});

return results;

//找到素有匹配pattern的枚举元素，结果作为数组返回，iterator可选，如果不指定旧返回素有匹配pattern的枚举元素

grep: function(pattern, iterator) {//正则模式迭代器

var results = [];

this.each(function(value, index) {

var stringValue = value.toString();

if (stringValue.match(pattern))

results.push((iterator || Prototype.K)(value, index));

})

return results;

//判断枚举对象中是否含有参数Object指定的值

include: function(object) {

var found = false;

this.each(function(value) {

if (value == object) {

found = true;

throw $break;

}

});

return found;

//将memo作为iterator的第一个参数，枚举元素作为iterator的第二个参数，枚举元素的次序作为第三个

//参数每次迭代器的返回值将作为下一个iterator的memo参数，从而所有的迭代执行都通过memo联系起来了

inject: function(memo, iterator) {

this.each(function(value, index) {

memo = iterator(memo, value, index);

});

return memo;

//对所有的枚举元素执行method方法后面是要传递的参数

invoke: function(method) {

var args = $A(arguments).slice(1);

return this.collect(function(value) {

return value[method].apply(value, args);

});

//返回的最大的迭代器执行结果

max: function(iterator) {

var result;

this.each(function(value, index) {

value = (iterator || Prototype.K)(value, index);

if (value >= (result || value))

result = value;

});

return result;

//反之

min: function(iterator) {

var result;

this.each(function(value, index) {

value = (iterator || Prototype.K)(value, index);

if (value <= (result || value))

result = value;

});

return result;

//返回两个数组一组能使iterator返回true 另一组返回false

partition: function(iterator) {

var trues = [], falses = [];

this.each(function(value, index) {

((iterator || Prototype.K)(value, index) ?

trues : falses).push(value);

});

return [trues, falses];

//获取所有枚举元素的property属性值作为数组的返回

pluck: function(property) {

var results = [];

this.each(function(value, index) {

results.push(value[property]);

});

return results;

//与findall相反

reject: function(iterator) {

var results = [];

this.each(function(value, index) {

if (!iterator(value, index))

results.push(value);

});

return results;

//根据iterator的结果排序最小的在前面作为数组返回

sortBy: function(iterator) {

return this.collect(function(value, index) {

return {value: value, criteria: iterator(value, index)};

}).sort(function(left, right) {

var a = left.criteria, b = right.criteria;

return a < b ? -1 : a > b ? 1 : 0;

}).pluck('value');

//枚举对象--》数组

toArray: function() {

return this.collect(Prototype.K);

//接收多个枚举对象参数，最后一个可以是迭代器用于阵列转换

zip: function() {

var iterator = Prototype.K, args = $A(arguments);

if (typeof args.last() == 'function')

iterator = args.pop();

var collections = [this].concat(args).map($A);

return this.map(function(value, index) {

iterator(value = collections.pluck(index));

return value;

});

//返回枚举对象的字符串描述

inspect: function() {

return '#<Enumerable:' + this.toArray().inspect() + '>';

}

//等价函数定义

Object.extend(Enumerable, {

map: Enumerable.collect,

find: Enumerable.detect,

select: Enumerable.findAll,

member: Enumerable.include,

entries: Enumerable.toArray

});

/*========================================================================================*/

//【Array】数组对象

//参数转换为数组，如果参数定义了toarray则直接调用，否则枚举获得数组

var $A = Array.from = function(iterable) {

if (!iterable) return [];

if (iterable.toArray) {

return iterable.toArray();

} else {

var results = [];

for (var i = 0; i < iterable.length; i++)

results.push(iterable[i]);

return results;

}

//数组对象继承了Enumerable接口

Object.extend(Array.prototype, Enumerable);

Array.prototype._reverse = Array.prototype.reverse;

Object.extend(Array.prototype, {

//实现了枚举接口方法，用于对数组内的元素执行迭代器

_each: function(iterator) {

for (var i = 0; i < this.length; i++)

iterator(this[i]);

//清空数组

clear: function() {

this.length = 0;

return this;

//取得第一个元素

first: function() {

return this[0];

//取得最后一个元素

last: function() {

return this[this.length - 1];

//删除数组元素中所有的null undefined值作为新数组返回，原数组不受影响

compact: function() {

return this.select(function(value) {

return value != undefined || value != null;

});

//展开所有数组元素不再嵌套

flatten: function() {

return this.inject([], function(array, value) {

return array.concat(value.constructor == Array ?

value.flatten() : [value]);

});

//数组中删除指定的元素，返回删除后的结果，原数组不受影响

without: function() {

var values = $A(arguments);

return this.select(function(value) {

return !values.include(value);

});

//Value元素在数组中的索引值

indexOf: function(object) {

for (var i = 0; i < this.length; i++)

if (this[i] == object) return i;

return -1;

//反转数组

reverse: function(inline) {

return (inline !== false ? this : this.toArray())._reverse();

//删除数组中第一个元素并返回这个元素的值

shift: function() {

var result = this[0];

for (var i = 0; i < this.length - 1; i++)

this[i] = this[i + 1];

this.length--;

return result;

//得到数组的字符串描述例如arr=[1,2,3]-----> "[1,2,3]"

inspect: function() {

return '[' + this.map(Object.inspect).join(', ') + ']';

}

});

/*========================================================================================*/

//【Hash】哈希对象

var Hash = {

//实现枚举接口方法从而使Hash对象也是枚举对象

_each: function(iterator) {

for (key in this) {

var value = this[key];

if (typeof value == 'function') continue;

var pair = [key, value];

pair.key = key;

pair.value = value;

iterator(pair);

}

//所有键数组

keys: function() {

return this.pluck('key');

//所有值数组

values: function() {

return this.pluck('value');

//合并哈希表，键相同就覆盖调用者

merge: function(hash) {

return $H(hash).inject($H(this), function(mergedHash, pair) {

mergedHash[pair.key] = pair.value;

return mergedHash;

});

//键值对组成查询字符串的形式

toQueryString: function() {

return this.map(function(pair) {

return pair.map(encodeURIComponent).join('=');

}).join('&');

//获取Hash对象的字符串描述

inspect: function() {

return '#<Hash:{' + this.map(function(pair) {

return pair.map(Object.inspect).join(': ');

}).join(', ') + '}>';

}

/*哈希表不是类而是对象所以不能用new的方法创建，而是用$H()函数

这个方法吧一个对象转换为哈希对象，对象的属性名为key 值为value

可枚举！！

function $H(object) {

var hash = Object.extend({}, object || {});

Object.extend(hash, Enumerable);

Object.extend(hash, Hash);

return hash;

}

/*========================================================================================*/

//【ObjectRange】用于进行指定次数的循环运算，同样继承于枚举接口并实现_each方法

//有了这个方法基本上Javascript里面就不用for循环了

ObjectRange = Class.create();

Object.extend(ObjectRange.prototype, Enumerable);

Object.extend(ObjectRange.prototype, {

//构造函数同事指定了3个参数的值

initialize: function(start, end, exclusive) {

this.start = start; //其实索引

this.end = end;//结束索引

this.exclusive = exclusive;//表示是否包含结束索引

_each: function(iterator) {

var value = this.start;

do {

iterator(value);

value = value.succ();

} while (this.include(value));

//重写枚举接口的include方法，判断改循环的索引是否包含参数value的指定的值

include: function(value) {

if (value < this.start)

return false;

if (this.exclusive)

return value < this.end;

return value <= this.end;

}

});

//使用$R()方法快速创建objectRange对象

var $R = function(start, end, exclusive) {

return new ObjectRange(start, end, exclusive);

}

/*========================================================================================*/

/* 【Ajax模块】

/*========================================================================================*/

//【ajax对象】

var Ajax = {//创建浏览器兼容的XMLHttpRequest对象

getTransport: function() {

return Try.these(

function() {return new ActiveXObject('Msxml2.XMLHTTP')},

function() {return new ActiveXObject('Microsoft.XMLHTTP')},

function() {return new XMLHttpRequest()}

) || false;

//当前激活的请求数目

activeRequestCount: 0

}

//【Ajax.Responders对象】

Ajax.Responders = {

responders: [],//表示所有响应处理代理

_each: function(iterator) {

this.responders._each(iterator);

//注册一个响应代理

if (!this.include(responderToAdd))

this.responders.push(responderToAdd);

//删除一个响应代理

unregister: function(responderToRemove) {

this.responders = this.responders.without(responderToRemove);

//分发一个回调函数，让所有半酣callback回调函数事件标识符的响应代理都被调用

//传递三个参数最后一个可选表示Json对象

dispatch: function(callback, request, transport, json) {

this.each(function(responder) {

if (responder[callback] && typeof responder[callback] == 'function') {

try {

responder[callback].apply(responder, [request, transport, json]);

} catch (e) {}

}

});

}

};

Object.extend(Ajax.Responders, Enumerable);

//统计当前活动请求的数目

Ajax.Responders.register({

//开始创建了一个请求

onCreate: function() {

Ajax.activeRequestCount++;

//请求结束

onComplete: function() {

Ajax.activeRequestCount--;

}

});

//【Ajax.Base类】进行服务器通信的基类

Ajax.Base = function() {};

Ajax.Base.prototype = {

setOptions: function(options) {

this.options = {

method: 'post',

asynchronous: true,

parameters: ''

}

Object.extend(this.options, options || {});

responseIsSuccess: function() {

return this.transport.status == undefined

|| this.transport.status == 0

|| (this.transport.status >= 200 && this.transport.status < 300);

responseIsFailure: function() {

return !this.responseIsSuccess();

}

//【Ajax.Request类】用于向服务器端发送请求，封装了XmlHttpRequest

Ajax.Request = Class.create();

Ajax.Request.Events =

['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Request.prototype = Object.extend(new Ajax.Base(), {

initialize: function(url, options) {

this.transport = Ajax.getTransport();

this.setOptions(options);//使用基类方法设置

this.request(url);

//向指定url发送请求一般不会显示调用

request: function(url) {

var parameters = this.options.parameters || '';

if (parameters.length > 0) parameters += '&_=';

try {

this.url = url;

if (this.options.method == 'get' && parameters.length > 0)

this.url += (this.url.match(/?/) ? '&' : '?') + parameters;

Ajax.Responders.dispatch('onCreate', this, this.transport);

this.transport.open(this.options.method, this.url,

this.options.asynchronous);

if (this.options.asynchronous) {

this.transport.onreadystatechange = this.onStateChange.bind(this);

setTimeout((function() {this.respondToReadyState(1)}).bind(this), 10);

}

this.setRequestHeaders();

var body = this.options.postBody ? this.options.postBody : parameters;

this.transport.send(this.options.method == 'post' ? body : null);

} catch (e) {

this.dispatchException(e);

}

//设置请求的Http头类内部使用一般无需显示调用

setRequestHeaders: function() {

var requestHeaders =

['X-Requested-With', 'XMLHttpRequest',

'X-Prototype-Version', Prototype.Version];

if (this.options.method == 'post') {

requestHeaders.push('Content-type',

'application/x-www-form-urlencoded');

/* Force "Connection: close" for Mozilla browsers to work around

* a bug where XMLHttpReqeuest sends an incorrect Content-length

* header. See Mozilla Bugzilla #246651.

if (this.transport.overrideMimeType)

requestHeaders.push('Connection', 'close');

}

if (this.options.requestHeaders)

requestHeaders.push.apply(requestHeaders, this.options.requestHeaders);

for (var i = 0; i < requestHeaders.length; i += 2)

this.transport.setRequestHeader(requestHeaders[i], requestHeaders[i+1]);

//检测XMLHttpRquest对象的onstatechange事件类内部使用一般无需显示调用

onStateChange: function() {

var readyState = this.transport.readyState;

if (readyState != 1)

this.respondToReadyState(this.transport.readyState);

//获取指定的Http头的内容

header: function(name) {

try {

return this.transport.getResponseHeader(name);

} catch (e) {}

//如果服务器返回了Http头"X-JOSN"则将其作为js执行并返回执行结果

evalJSON: function() {

try {

return eval(this.header('X-JSON'));

} catch (e) {}

//将XMLHttpRequest返回的responseText作为JS语句执行并返回执行结果

evalResponse: function() {

try {

return eval(this.transport.responseText);

} catch (e) {

this.dispatchException(e);

}

//处理XMLHttpRequest的readystate属性根据成功或失败调用Options对象中相应的回调函数

//同时通知Ajax.Responders中注册的响应处理句柄

respondToReadyState: function(readyState) {

var event = Ajax.Request.Events[readyState];

var transport = this.transport, json = this.evalJSON();

if (event == 'Complete') {

try {

(this.options['on' + this.transport.status]

|| this.options['on' + (this.responseIsSuccess() ? 'Success' : 'Failure')]

|| Prototype.emptyFunction)(transport, json);

} catch (e) {

this.dispatchException(e);

}

if ((this.header('Content-type') || '').match(/^text/javascript/i))

this.evalResponse();

}

try {

(this.options['on' + event] || Prototype.emptyFunction)(transport, json);

Ajax.Responders.dispatch('on' + event, this, transport, json);

} catch (e) {

this.dispatchException(e);

}

/* Avoid memory leak in MSIE: clean up the oncomplete event handler */

if (event == 'Complete')

this.transport.onreadystatechange = Prototype.emptyFunction;

dispatchException: function(exception) {

(this.options.onException || Prototype.emptyFunction)(this, exception);

Ajax.Responders.dispatch('onException', this, exception);

}

});

/*========================================================================================*/

//【Ajax.Updater类】用于将获取的内容填充到指定的容器中去

Ajax.Updater = Class.create();

Object.extend(Object.extend(Ajax.Updater.prototype, Ajax.Request.prototype), {

//重写了构造函数

initialize: function(container, url, options) {

this.containers = {

success: container.success ? $(container.success) : $(container),

failure: container.failure ? $(container.failure) :

(container.success ? null : $(container))

}

this.transport = Ajax.getTransport();

this.setOptions(options);//可以指定evalscripts属性和insertion属性

var onComplete = this.options.onComplete || Prototype.emptyFunction;

this.options.onComplete = (function(transport, object) {

this.updateContent();

onComplete(transport, object);

}).bind(this);

this.request(url);

updateContent: function() {

var receiver = this.responseIsSuccess() ?

this.containers.success : this.containers.failure;

var response = this.transport.responseText;

if (!this.options.evalScripts)

response = response.stripScripts();

if (receiver) {

if (this.options.insertion) {

new this.options.insertion(receiver, response);

} else {

Element.update(receiver, response);

}

if (this.responseIsSuccess()) {

if (this.onComplete)

setTimeout(this.onComplete.bind(this), 10);

}

});

/*========================================================================================*/

//【Ajax.PeriodicalUpdater类】用于定时执行服务器异步调用，功能与Updater相同只是有了定时功能

Ajax.PeriodicalUpdater = Class.create();

Ajax.PeriodicalUpdater.prototype = Object.extend(new Ajax.Base(), {

initialize: function(container, url, options) {

this.setOptions(options);

this.onComplete = this.options.onComplete;

//区别就在下面两个属性频率衰减参数指数增长！只要有一次不同旧回复原有频率

this.frequency = (this.options.frequency || 2);

this.decay = (this.options.decay || 1);

this.updater = {};

this.container = container;

this.url = url;

this.start();

start: function() {

this.options.onComplete = this.updateComplete.bind(this);

this.onTimerEvent();

stop: function() {

this.updater.onComplete = undefined;

clearTimeout(this.timer);

(this.onComplete || Prototype.emptyFunction).apply(this, arguments);

updateComplete: function(request) {

if (this.options.decay) {

this.decay = (request.responseText == this.lastText ?

this.decay * this.options.decay : 1);

this.lastText = request.responseText;

}

this.timer = setTimeout(this.onTimerEvent.bind(this),

this.decay * this.frequency * 1000);

onTimerEvent: function() {

this.updater = new Ajax.Updater(this.container, this.url, this.options);

}

});

/*========================================================================================*/

/*【文档操作的封装】

/*========================================================================================*/

//返回了一个数组包含了所有符合条件的结点的引用

document.getElementsByClassName = function(className, parentElement) { //parentElement不指定就在全局查找

var children = ($(parentElement) || document.body).getElementsByTagName('*');

return $A(children).inject([], function(elements, child) {

if (child.className.match(new RegExp("(^|\s)" + className + "(\s|$)")))

elements.push(child);

return elements;

});

}

/*【Element对象】用于对文档结点做一些统一的操作

if (!window.Element) {

var Element = new Object();

}

Object.extend(Element, {

visible: function(element) {

return $(element).style.display != 'none';

//指定结点可见性的切换

toggle: function() {

for (var i = 0; i < arguments.length; i++) {

var element = $(arguments[i]);

Element[Element.visible(element) ? 'hide' : 'show'](element);

}

hide: function() {

for (var i = 0; i < arguments.length; i++) {

var element = $(arguments[i]);

element.style.display = 'none';

}

show: function() {

for (var i = 0; i < arguments.length; i++) {

var element = $(arguments[i]);

element.style.display = '';

}

remove: function(element) {

element = $(element);

element.parentNode.removeChild(element);

//将html片段填充到element指定的结点中

update: function(element, html) {

$(element).innerHTML = html.stripScripts();

setTimeout(function() {html.evalScripts()}, 10);

//获得element的绝对高度

getHeight: function(element) {

element = $(element);

return element.offsetHeight;

classNames: function(element) {

return new Element.ClassNames(element);

hasClassName: function(element, className) {

if (!(element = $(element))) return;

return Element.classNames(element).include(className);

addClassName: function(element, className) {

if (!(element = $(element))) return;

return Element.classNames(element).add(className);

removeClassName: function(element, className) {

if (!(element = $(element))) return;

return Element.classNames(element).remove(className);

// removes whitespace-only text node children

cleanWhitespace: function(element) {

element = $(element);

for (var i = 0; i < element.childNodes.length; i++) {

var node = element.childNodes[i];

if (node.nodeType == 3 && !/S/.test(node.nodeValue))

Element.remove(node);

}

empty: function(element) {

return $(element).innerHTML.match(/^s*$/);

//将浏览器的滚动条滚动到指定的结点的位置

scrollTo: function(element) {

element = $(element);

var x = element.x ? element.x : element.offsetLeft,

y = element.y ? element.y : element.offsetTop;

window.scrollTo(x, y);

//得到element的结点的绝对样式

getStyle: function(element, style) {

element = $(element);

var value = element.style[style.camelize()];

if (!value) {

if (document.defaultView && document.defaultView.getComputedStyle) {

var css = document.defaultView.getComputedStyle(element, null);

value = css ? css.getPropertyValue(style) : null;

} else if (element.currentStyle) {

value = element.currentStyle[style.camelize()];

}

if (window.opera && ['left', 'top', 'right', 'bottom'].include(style))

if (Element.getStyle(element, 'position') == 'static') value = 'auto';

return value == 'auto' ? null : value;

//设置结点样式 var style={background-color:'black',color:'red'} Element.setStyle($('div1'),style)

setStyle: function(element, style) {

element = $(element);

for (name in style)

element.style[name.camelize()] = style[name];

//获得结点的宽度高度该方法无论结点是否可见都能获得其大小

getDimensions: function(element) {

element = $(element);

if (Element.getStyle(element, 'display') != 'none')

return {width: element.offsetWidth, height: element.offsetHeight};

// All *Width and *Height properties give 0 on elements with display none,

// so enable the element temporarily

var els = element.style;

var originalVisibility = els.visibility;

var originalPosition = els.position;

els.visibility = 'hidden';

els.position = 'absolute';

els.display = '';

var originalWidth = element.clientWidth;

var originalHeight = element.clientHeight;

els.display = 'none';

els.position = originalPosition;

els.visibility = originalVisibility;

return {width: originalWidth, height: originalHeight};

//相对定位

makePositioned: function(element) {

element = $(element);

var pos = Element.getStyle(element, 'position');

if (pos == 'static' || !pos) {

element._madePositioned = true;

element.style.position = 'relative';

// Opera returns the offset relative to the positioning context, when an

// element is position relative but top and left have not been defined

if (window.opera) {

element.style.top = 0;

element.style.left = 0;

}

//取消相对定位

undoPositioned: function(element) {

element = $(element);

if (element._madePositioned) {

element._madePositioned = undefined;

element.style.position =

element.style.top =

element.style.left =

element.style.bottom =

element.style.right = '';

}

//使结点隐藏超出的部分 overflow=relative

makeClipping: function(element) {

element = $(element);

if (element._overflow) return;

element._overflow = element.style.overflow;

if ((Element.getStyle(element, 'overflow') || 'visible') != 'hidden')

element.style.overflow = 'hidden';

undoClipping: function(element) {

element = $(element);

if (element._overflow) return;

element.style.overflow = element._overflow;

element._overflow = undefined;

}

});

/*========================================================================================*/

//Toggle对象是Element.toggle方法的一个快捷用法

var Toggle = new Object();

Toggle.display = Element.toggle;

/*========================================================================================*/

//【Insertion命名空间】包含了4个类把指定的html片段插入到指定的结点的相应位置上

Abstract.Insertion = function(adjacency) {

this.adjacency = adjacency;

}

Abstract.Insertion.prototype = {

initialize: function(element, content) {

this.element = $(element);

this.content = content.stripScripts();

if (this.adjacency && this.element.insertAdjacentHTML) {

try {

this.element.insertAdjacentHTML(this.adjacency, this.content);

} catch (e) {

if (this.element.tagName.toLowerCase() == 'tbody') {

this.insertContent(this.contentFromAnonymousTable());

} else {

throw e;

}

} else {

this.range = this.element.ownerDocument.createRange();

if (this.initializeRange) this.initializeRange();

this.insertContent([this.range.createContextualFragment(this.content)]);

}

setTimeout(function() {content.evalScripts()}, 10);

contentFromAnonymousTable: function() {

var div = document.createElement('div');

div.innerHTML = '<table><tbody>' + this.content + '</tbody></table>';

return $A(div.childNodes[0].childNodes[0].childNodes);

}

var Insertion = new Object();

Insertion.Before = Class.create();

Insertion.Before.prototype = Object.extend(new Abstract.Insertion('beforeBegin'), {

initializeRange: function() {

this.range.setStartBefore(this.element);

insertContent: function(fragments) {

fragments.each((function(fragment) {

this.element.parentNode.insertBefore(fragment, this.element);

}).bind(this));

}

});

Insertion.Top = Class.create();

Insertion.Top.prototype = Object.extend(new Abstract.Insertion('afterBegin'), {

initializeRange: function() {

this.range.selectNodeContents(this.element);

this.range.collapse(true);

insertContent: function(fragments) {

fragments.reverse(false).each((function(fragment) {

this.element.insertBefore(fragment, this.element.firstChild);

}).bind(this));

}

});

Insertion.Bottom = Class.create();

Insertion.Bottom.prototype = Object.extend(new Abstract.Insertion('beforeEnd'), {

initializeRange: function() {

this.range.selectNodeContents(this.element);

this.range.collapse(this.element);

insertContent: function(fragments) {

fragments.each((function(fragment) {

this.element.appendChild(fragment);

}).bind(this));

}

});

Insertion.After = Class.create();

Insertion.After.prototype = Object.extend(new Abstract.Insertion('afterEnd'), {

initializeRange: function() {

this.range.setStartAfter(this.element);

insertContent: function(fragments) {

fragments.each((function(fragment) {

this.element.parentNode.insertBefore(fragment,

this.element.nextSibling);

}).bind(this));

}

});

/*========================================================================================*/

//【Element.ClassNames】获得一个结点的所有的class名称组成的对象，实现了枚举接口

Element.ClassNames = Class.create();

Element.ClassNames.prototype = {

initialize: function(element) {

this.element = $(element);

_each: function(iterator) {

this.element.className.split(/s+/).select(function(name) {

return name.length > 0;

})._each(iterator);

set: function(className) {

this.element.className = className;

add: function(classNameToAdd) {

if (this.include(classNameToAdd)) return;

this.set(this.toArray().concat(classNameToAdd).join(' '));

remove: function(classNameToRemove) {

if (!this.include(classNameToRemove)) return;

this.set(this.select(function(className) {

return className != classNameToRemove;

}).join(' '));

toString: function() {//获得所有class的字符串表示空格隔开

return this.toArray().join(' ');

}

//表单域对象工具类

Object.extend(Element.ClassNames.prototype, Enumerable);

var Field = {

clear: function() {

for (var i = 0; i < arguments.length; i++)

$(arguments[i]).value = '';

focus: function(element) {

$(element).focus();

present: function() {

for (var i = 0; i < arguments.length; i++)

if ($(arguments[i]).value == '') return false;

return true;

//选中表单域

select: function(element) {

$(element).select();

//focus + select

activate: function(element) {

element = $(element);

element.focus();

if (element.select)

element.select();

}

/*【Form】表单工具对象*/

var Form = {

//表单数据序列化

serialize: function(form) {

var elements = Form.getElements($(form));

var queryComponents = new Array();

for (var i = 0; i < elements.length; i++) {

var queryComponent = Form.Element.serialize(elements[i]);

if (queryComponent)

queryComponents.push(queryComponent);

}

return queryComponents.join('&');

//获取所有表单域按照标记名排列

getElements: function(form) {

form = $(form);

var elements = new Array();

for (tagName in Form.Element.Serializers) {

var tagElements = form.getElementsByTagName(tagName);

for (var j = 0; j < tagElements.length; j++)

elements.push(tagElements[j]);

}

return elements;

//有一个满足就返回

getInputs: function(form, typeName, name) {

form = $(form);

var inputs = form.getElementsByTagName('input');

if (!typeName && !name)

return inputs;

var matchingInputs = new Array();

for (var i = 0; i < inputs.length; i++) {

var input = inputs[i];

if ((typeName && input.type != typeName) ||

(name && input.name != name))

continue;

matchingInputs.push(input);

}

return matchingInputs;

//整个表单域禁用

disable: function(form) {

var elements = Form.getElements(form);

for (var i = 0; i < elements.length; i++) {

var element = elements[i];

element.blur();

element.disabled = 'true';

}

//启用

enable: function(form) {

var elements = Form.getElements(form);

for (var i = 0; i < elements.length; i++) {

var element = elements[i];

element.disabled = '';

}

//获取第一个可用的表单域

findFirstElement: function(form) {

return Form.getElements(form).find(function(element) {

return element.type != 'hidden' && !element.disabled &&

['input', 'select', 'textarea'].include(element.tagName.toLowerCase());

});

//激活第一个表单域

focusFirstElement: function(form) {

Field.activate(Form.findFirstElement(form));

reset: function(form) {

$(form).reset();

}

//【Form.Element】对特定的表单域进行操作

Form.Element = {

//序列化形成"&name=value"

serialize: function(element) {

element = $(element);

var method = element.tagName.toLowerCase();

var parameter = Form.Element.Serializers[method](element);

if (parameter) {

var key = encodeURIComponent(parameter[0]);

if (key.length == 0) return;

if (parameter[1].constructor != Array)

parameter[1] = [parameter[1]];

return parameter[1].map(function(value) {

return key + '=' + encodeURIComponent(value);

}).join('&');

}

//获得指定表单域的值

getValue: function(element) {

element = $(element);

var method = element.tagName.toLowerCase();

var parameter = Form.Element.Serializers[method](element);

if (parameter)

return parameter[1];

}

//【Form.Element.Serializers】针对不同的表单域进行序列化

Form.Element.Serializers = {

//一般用所有的<input>标记的序列化都可以

input: function(element) {

switch (element.type.toLowerCase()) {

case 'submit':

case 'hidden':

case 'password':

case 'text':

return Form.Element.Serializers.textarea(element);

case 'checkbox':

case 'radio':

return Form.Element.Serializers.inputSelector(element);

}

return false;

inputSelector: function(element) {

if (element.checked)

return [element.name, element.value];

textarea: function(element) {

return [element.name, element.value];

select: function(element) {

return Form.Element.Serializers[element.type == 'select-one' ?

'selectOne' : 'selectMany'](element);

selectOne: function(element) {

var value = '', opt, index = element.selectedIndex;

if (index >= 0) {

opt = element.options[index];

value = opt.value;

if (!value && !('value' in opt))

value = opt.text;

}

return [element.name, value];

selectMany: function(element) {

var value = new Array();

for (var i = 0; i < element.length; i++) {

var opt = element.options[i];

if (opt.selected) {

var optValue = opt.value;

if (!optValue && !('value' in opt))

optValue = opt.text;

value.push(optValue);

}

return [element.name, value];

}

//【获得表单域的值】

var $F = Form.Element.getValue;

/*========================================================================================*/

/*【Observer模式框架】观察对象仅仅针对表单和表单域*/

/*========================================================================================*/

Abstract.TimedObserver = function() {}//定义了基于定时器的观察模式基类后面的类都继承了这个类

Abstract.TimedObserver.prototype = {

initialize: function(element, frequency, callback) {

this.frequency = frequency;//观察频率

this.element = $(element);//被观察的对象

this.callback = callback;//回调函数接受参数被观察对象自身和触发事件时的值

this.lastValue = this.getValue();//这是观察的值！！

this.registerCallback();

//注册回调函数

registerCallback: function() {

setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);

//每一个时间片触发一次该事件

onTimerEvent: function() {

var value = this.getValue();

if (this.lastValue != value) {

this.callback(this.element, value);

this.lastValue = value;

}

//【Form.Element.Observer类】实现了getvalue方法

Form.Element.Observer = Class.create();

Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {

getValue: function() {

return Form.Element.getValue(this.element);

}

});

//【Form.Observer类】实现了getvalue方法，只要有一个表单域发生变化就会触发回调

Form.Observer = Class.create();

Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {

getValue: function() {

return Form.serialize(this.element);

}

});

//【Abstract.EventObserver 类】基于事件的Oberver模式的基类后面的具体类都继承这个类

Abstract.EventObserver = function() {}

Abstract.EventObserver.prototype = {

initialize: function(element, callback) {

this.element = $(element);

this.callback = callback;

this.lastValue = this.getValue();

if (this.element.tagName.toLowerCase() == 'form')

this.registerFormCallbacks();

else

this.registerCallback(this.element);

//每次发生事件时被调用内部调用无需显示调用

onElementEvent: function() {

var value = this.getValue();

if (this.lastValue != value) {

this.callback(this.element, value);

this.lastValue = value;

}

//注册表表单域事件

registerFormCallbacks: function() {

var elements = Form.getElements(this.element);

for (var i = 0; i < elements.length; i++)

this.registerCallback(elements[i]);

registerCallback: function(element) {

if (element.type) {

switch (element.type.toLowerCase()) {

case 'checkbox':

case 'radio':

Event.observe(element, 'click', this.onElementEvent.bind(this));

break;

case 'password':

case 'text':

case 'textarea':

case 'select-one':

case 'select-multiple':

Event.observe(element, 'change', this.onElementEvent.bind(this));

break;

}

//【Form.Element.EventObserver】

Form.Element.EventObserver = Class.create();

Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {

getValue: function() {

return Form.Element.getValue(this.element);

}

});

//【Form.EventObserver】

Form.EventObserver = Class.create();

Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {

getValue: function() {

return Form.serialize(this.element);

}

});

/*========================================================================================*/

/*【事件处理:对Event对象的扩展】对javascript事件处理机制进行封装*/

/*========================================================================================*/

if (!window.Event) {

var Event = new Object();

}

Object.extend(Event, {

KEY_BACKSPACE: 8,

KEY_TAB: 9,

KEY_RETURN: 13,

KEY_ESC: 27,

KEY_LEFT: 37,

KEY_UP: 38,

KEY_RIGHT: 39,

KEY_DOWN: 40,

KEY_DELETE: 46,

//获取触发事件的对象

element: function(event) {

return event.target || event.srcElement;

isLeftClick: function(event) {

return (((event.which) && (event.which == 1)) ||

((event.button) && (event.button == 1)));

pointerX: function(event) {

return event.pageX || (event.clientX +

(document.documentElement.scrollLeft || document.body.scrollLeft));

pointerY: function(event) {

return event.pageY || (event.clientY +

(document.documentElement.scrollTop || document.body.scrollTop));

//停止事件的传递

stop: function(event) {

if (event.preventDefault) {

event.preventDefault();

event.stopPropagation();

} else {

event.returnValue = false;

event.cancelBubble = true;

}

// find the first node with the given tagName, starting from the

// node the event was triggered on; traverses the DOM upwards

findElement: function(event, tagName) {

var element = Event.element(event);

while (element.parentNode && (!element.tagName ||

(element.tagName.toUpperCase() != tagName.toUpperCase())))

element = element.parentNode;

return element;

observers: false,

_observeAndCache: function(element, name, observer, useCapture) {

if (!this.observers) this.observers = [];

if (element.addEventListener) {

this.observers.push([element, name, observer, useCapture]);

element.addEventListener(name, observer, useCapture);

} else if (element.attachEvent) {

this.observers.push([element, name, observer, useCapture]);

element.attachEvent('on' + name, observer);

}

//删除所有通过Event.observers绑定的事件

unloadCache: function() {

if (!Event.observers) return;

for (var i = 0; i < Event.observers.length; i++) {

Event.stopObserving.apply(this, Event.observers[i]);

Event.observers[i][0] = null;

}

Event.observers = false;

//绑定一个事件

observe: function(element, name, observer, useCapture) {

var element = $(element);

useCapture = useCapture || false;

if (name == 'keypress' &&

(navigator.appVersion.match(/Konqueror|Safari|KHTML/)

|| element.attachEvent))

name = 'keydown';

this._observeAndCache(element, name, observer, useCapture);

//取消事件绑定

stopObserving: function(element, name, observer, useCapture) {

var element = $(element);

useCapture = useCapture || false;

if (name == 'keypress' &&

(navigator.appVersion.match(/Konqueror|Safari|KHTML/)

|| element.detachEvent))

name = 'keydown';

if (element.removeEventListener) {

element.removeEventListener(name, observer, useCapture);

} else if (element.detachEvent) {

element.detachEvent('on' + name, observer);

}

});

//【结点的位置处理:Position对象】

/* prevent memory leaks in IE */

Event.observe(window, 'unload', Event.unloadCache, false);

var Position = {

// set to true if needed, warning: firefox performance problems

// NOT neeeded for page scrolling, only if draggable contained in

// scrollable elements

includeScrollOffsets: false,

// must be called before calling withinIncludingScrolloffset, every time the

// page is scrolled用于计算滚动条的位置信息

prepare: function() {

this.deltaX = window.pageXOffset

|| document.documentElement.scrollLeft

|| document.body.scrollLeft

|| 0;

this.deltaY = window.pageYOffset

|| document.documentElement.scrollTop

|| document.body.scrollTop

|| 0;

//计算节点的绝对滚动位置返回包含两个元素的数组到文档左侧顶部的距离

realOffset: function(element) {

var valueT = 0, valueL = 0;

do {

valueT += element.scrollTop || 0;

valueL += element.scrollLeft || 0;

element = element.parentNode;

} while (element);

return [valueL, valueT];

//计算结点相对于文档的绝对滚动位置，返回包含两个元素的数组到文档左侧顶部的距离

cumulativeOffset: function(element) {

var valueT = 0, valueL = 0;

do {

valueT += element.offsetTop || 0;

valueL += element.offsetLeft || 0;

element = element.offsetParent;

} while (element);

return [valueL, valueT];

//相对位置

positionedOffset: function(element) {

var valueT = 0, valueL = 0;

do {

valueT += element.offsetTop || 0;

valueL += element.offsetLeft || 0;

element = element.offsetParent;

if (element) {

p = Element.getStyle(element, 'position');

if (p == 'relative' || p == 'absolute') break;

}

} while (element);

return [valueL, valueT];

offsetParent: function(element) {

if (element.offsetParent) return element.offsetParent;

if (element == document.body) return element;

while ((element = element.parentNode) && element != document.body)

if (Element.getStyle(element, 'position') != 'static')

return element;

return document.body;

// caches x/y coordinate pair to use with overlap是否在element内

within: function(element, x, y) {

if (this.includeScrollOffsets)

return this.withinIncludingScrolloffsets(element, x, y);

this.xcomp = x;

this.ycomp = y;

this.offset = this.cumulativeOffset(element);

return (y >= this.offset[1] &&

y < this.offset[1] + element.offsetHeight &&

x >= this.offset[0] &&

x < this.offset[0] + element.offsetWidth);

withinIncludingScrolloffsets: function(element, x, y) {

var offsetcache = this.realOffset(element);

this.xcomp = x + offsetcache[0] - this.deltaX;

this.ycomp = y + offsetcache[1] - this.deltaY;

this.offset = this.cumulativeOffset(element);

return (this.ycomp >= this.offset[1] &&

this.ycomp < this.offset[1] + element.offsetHeight &&

this.xcomp >= this.offset[0] &&

this.xcomp < this.offset[0] + element.offsetWidth);

// within must be called directly before

overlap: function(mode, element) {

if (!mode) return 0;

if (mode == 'vertical')

return ((this.offset[1] + element.offsetHeight) - this.ycomp) /

element.offsetHeight;

if (mode == 'horizontal')

return ((this.offset[0] + element.offsetWidth) - this.xcomp) /

element.offsetWidth;

//克隆结点常用于拖放

clone: function(source, target) {

source = $(source);

target = $(target);

target.style.position = 'absolute';

var offsets = this.cumulativeOffset(source);

target.style.top = offsets[1] + 'px';

target.style.left = offsets[0] + 'px';

target.style.width = source.offsetWidth + 'px';

target.style.height = source.offsetHeight + 'px';

page: function(forElement) {

var valueT = 0, valueL = 0;

var element = forElement;

do {

valueT += element.offsetTop || 0;

valueL += element.offsetLeft || 0;

// Safari fix

if (element.offsetParent==document.body)

if (Element.getStyle(element,'position')=='absolute') break;

} while (element = element.offsetParent);

element = forElement;

do {

valueT -= element.scrollTop || 0;

valueL -= element.scrollLeft || 0;

} while (element = element.parentNode);

return [valueL, valueT];

clone: function(source, target) {

var options = Object.extend({

setLeft: true,

setTop: true,

setWidth: true,

setHeight: true,

offsetTop: 0,

offsetLeft: 0

}, arguments[2] || {})

// find page position of source

source = $(source);

var p = Position.page(source);

// find coordinate system to use

target = $(target);

var delta = [0, 0];

var parent = null;

// delta [0,0] will do fine with position: fixed elements,

// position:absolute needs offsetParent deltas

if (Element.getStyle(target,'position') == 'absolute') {

parent = Position.offsetParent(target);

delta = Position.page(parent);

}

// correct by body offsets (fixes Safari)

if (parent == document.body) {

delta[0] -= document.body.offsetLeft;

delta[1] -= document.body.offsetTop;

}

// set position

if(options.setLeft) target.style.left = (p[0] - delta[0] + options.offsetLeft) + 'px';

if(options.setTop) target.style.top = (p[1] - delta[1] + options.offsetTop) + 'px';

if(options.setWidth) target.style.width = source.offsetWidth + 'px';

if(options.setHeight) target.style.height = source.offsetHeight + 'px';

//绝对定位

absolutize: function(element) {

element = $(element);

if (element.style.position == 'absolute') return;

Position.prepare();

var offsets = Position.positionedOffset(element);

var top = offsets[1];

var left = offsets[0];

var width = element.clientWidth;

var height = element.clientHeight;

element._originalLeft = left - parseFloat(element.style.left || 0);

element._originalTop = top - parseFloat(element.style.top || 0);

element._originalWidth = element.style.width;

element._originalHeight = element.style.height;

element.style.position = 'absolute';

element.style.top = top + 'px';;

element.style.left = left + 'px';;

element.style.width = width + 'px';;

element.style.height = height + 'px';;

//相对定位

relativize: function(element) {

element = $(element);

if (element.style.position == 'relative') return;

Position.prepare();

element.style.position = 'relative';

var top = parseFloat(element.style.top || 0) - (element._originalTop || 0);

var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);

element.style.top = top + 'px';

element.style.left = left + 'px';

element.style.height = element._originalHeight;

element.style.width = element._originalWidth;

}

// Safari returns margins on body which is incorrect if the child is absolutely

// positioned. For performance reasons, redefine Position.cumulativeOffset for

// KHTML/WebKit only.

if (/Konqueror|Safari|KHTML/.test(navigator.userAgent)) {

Position.cumulativeOffset = function(element) {

var valueT = 0, valueL = 0;

do {

valueT += element.offsetTop || 0;

valueL += element.offsetLeft || 0;

if (element.offsetParent == document.body)

if (Element.getStyle(element, 'position') == 'absolute') break;

element = element.offsetParent;

} while (element);

return [valueL, valueT];

}

//--------->完成
[/js]