asins/IE getter setter

## IE getter setter
<!DOCTYPE html>
<html>
<head>
  <title>A Crazy Getter/Setter Hack</title>
</head>
<body>
<ul>
  <li>Object.defineProperty API：https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty</li>
  <li>https://github.com/RubyLouvre/avalon/blob/master/avalon.shim.js#L1394</li>
  <li>https://gist.github.com/jeffrafter/189354</li>
  <li>http://download.dojotoolkit.org/release-1.9.7/dojo-release-1.9.7/dojox/lang/observable.js.uncompressed.js</li>
</ul>

<pre>
通过vbscript来hack的方式勉强可用，不过有以下缺点：（https://github.com/migijs/migi/issues/5#issuecomment-103778075）

1. vbscript是不区分大小写的
2. vbscript不能增删属性，所以每次需重新定义class，实现上麻烦且bug，且无法确保如delete之类的语义
3. 性能糟糕
4. 很大的内存泄漏风险（因为vbscript的垃圾回收机制是计数）
</pre>

<script type="text/javascript">
var defineProperty = Object.defineProperty
var canHideOwn = true
//如果浏览器不支持ecma262v5的Object.defineProperties或者存在BUG，比如IE8
//标准浏览器使用__defineGetter__, __defineSetter__实现
try {
    defineProperty({}, "_", {
        value: "x"
    })
    var defineProperties = Object.defineProperties
} catch (e) {
    canHideOwn = false
}

if (!canHideOwn) {
    if ("__defineGetter__" in avalon) {
        defineProperty = function (obj, prop, desc) {
            if ('value' in desc) {
                obj[prop] = desc.value
            }
            if ("get" in desc) {
                obj.__defineGetter__(prop, desc.get)
            }
            if ('set' in desc) {
                obj.__defineSetter__(prop, desc.set)
            }
            return obj
        }
        defineProperties = function (obj, descs) {
            for (var prop in descs) {
                if (descs.hasOwnProperty(prop)) {
                    defineProperty(obj, prop, descs[prop])
                }
            }
            return obj
        }
    }
    if (IEVersion) {
        window.execScript([ // jshint ignore:line
            "Function parseVB(code)",
            "\tExecuteGlobal(code)",
            "End Function",
            "Dim VBClassBodies",
            "Set VBClassBodies=CreateObject(\"Scripting.Dictionary\")",
            "Function findOrDefineVBClass(name,body)",
            "\tDim found",
            "\tfound=\"\"",
            "\tFor Each key in VBClassBodies",
            "\t\tIf body=VBClassBodies.Item(key) Then",
            "\t\t\tfound=key",
            "\t\t\tExit For",
            "\t\tEnd If",
            "\tnext",
            "\tIf found=\"\" Then",
            "\t\tparseVB(\"Class \" + name + body)",
            "\t\tVBClassBodies.Add name, body",
            "\t\tfound=name",
            "\tEnd If",
            "\tfindOrDefineVBClass=found",
            "End Function"
        ].join("\n"), "VBScript")
        function VBMediator(instance, accessors, name, value) {// jshint ignore:line
            var accessor = accessors[name]
            if (arguments.length === 4) {
                accessor.call(instance, value)
            } else {
                return accessor.call(instance)
            }
        }
        defineProperties = function (name, accessors, properties) {
            var className = "VBClass" + setTimeout("1"),// jshint ignore:line
                    buffer = []
            buffer.push(
                    "\r\n\tPrivate [__data__], [__proxy__]",
                    "\tPublic Default Function [__const__](d, p)",
                    "\t\tSet [__data__] = d: set [__proxy__] = p",
                    "\t\tSet [__const__] = Me", //链式调用
                    "\tEnd Function")
            //添加普通属性,因为VBScript对象不能像JS那样随意增删属性，必须在这里预先定义好
            for (name in properties) {
                if (!accessors.hasOwnProperty(name)) {
                    buffer.push("\tPublic [" + name + "]")
                }
            }
            $$skipArray.forEach(function (name) {
                if (!accessors.hasOwnProperty(name)) {
                    buffer.push("\tPublic [" + name + "]")
                }
            })
            buffer.push("\tPublic [" + 'hasOwnProperty' + "]")
            //添加访问器属性
            for (name in accessors) {
                buffer.push(
                        //由于不知对方会传入什么,因此set, let都用上
                        "\tPublic Property Let [" + name + "](val" + expose + ")", //setter
                        "\t\tCall [__proxy__](Me,[__data__], \"" + name + "\", val" + expose + ")",
                        "\tEnd Property",
                        "\tPublic Property Set [" + name + "](val" + expose + ")", //setter
                        "\t\tCall [__proxy__](Me,[__data__], \"" + name + "\", val" + expose + ")",
                        "\tEnd Property",
                        "\tPublic Property Get [" + name + "]", //getter
                        "\tOn Error Resume Next", //必须优先使用set语句,否则它会误将数组当字符串返回
                        "\t\tSet[" + name + "] = [__proxy__](Me,[__data__],\"" + name + "\")",
                        "\tIf Err.Number <> 0 Then",
                        "\t\t[" + name + "] = [__proxy__](Me,[__data__],\"" + name + "\")",
                        "\tEnd If",
                        "\tOn Error Goto 0",
                        "\tEnd Property")

            }

            buffer.push("End Class")
            var code = buffer.join("\r\n"),
                    realClassName = window['findOrDefineVBClass'](className, code) //如果该VB类已定义，返回类名。否则用className创建一个新类。
            if (realClassName === className) {
                window.parseVB([
                    "Function " + className + "Factory(a, b)", //创建实例并传入两个关键的参数
                    "\tDim o",
                    "\tSet o = (New " + className + ")(a, b)",
                    "\tSet " + className + "Factory = o",
                    "End Function"
                ].join("\r\n"))
            }
            var ret = window[realClassName + "Factory"](accessors, VBMediator) //得到其产品
            return ret //得到其产品
        }
    }
}
  </script>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<title>A Crazy Getter/Setter Hack</title>
	</head>
	<body>
	<ul>
	<li>Object.defineProperty API：https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty</li>
	<li>https://github.com/RubyLouvre/avalon/blob/master/avalon.shim.js#L1394</li>
	<li>https://gist.github.com/jeffrafter/189354</li>
	<li>http://download.dojotoolkit.org/release-1.9.7/dojo-release-1.9.7/dojox/lang/observable.js.uncompressed.js</li>
	</ul>

	<pre>
	通过vbscript来hack的方式勉强可用，不过有以下缺点：（https://github.com/migijs/migi/issues/5#issuecomment-103778075）

	1. vbscript是不区分大小写的
	2. vbscript不能增删属性，所以每次需重新定义class，实现上麻烦且bug，且无法确保如delete之类的语义
	3. 性能糟糕
	4. 很大的内存泄漏风险（因为vbscript的垃圾回收机制是计数）
	</pre>

	<script type="text/javascript">
	var defineProperty = Object.defineProperty
	var canHideOwn = true
	//如果浏览器不支持ecma262v5的Object.defineProperties或者存在BUG，比如IE8
	//标准浏览器使用__defineGetter__, __defineSetter__实现
	try {
	defineProperty({}, "_", {
	value: "x"
	})
	var defineProperties = Object.defineProperties
	} catch (e) {
	canHideOwn = false
	}

	if (!canHideOwn) {
	if ("__defineGetter__" in avalon) {
	defineProperty = function (obj, prop, desc) {
	if ('value' in desc) {
	obj[prop] = desc.value
	}
	if ("get" in desc) {
	obj.__defineGetter__(prop, desc.get)
	}
	if ('set' in desc) {
	obj.__defineSetter__(prop, desc.set)
	}
	return obj
	}
	defineProperties = function (obj, descs) {
	for (var prop in descs) {
	if (descs.hasOwnProperty(prop)) {
	defineProperty(obj, prop, descs[prop])
	}
	}
	return obj
	}
	}
	if (IEVersion) {
	window.execScript([ // jshint ignore:line
	"Function parseVB(code)",
	"\tExecuteGlobal(code)",
	"End Function",
	"Dim VBClassBodies",
	"Set VBClassBodies=CreateObject(\"Scripting.Dictionary\")",
	"Function findOrDefineVBClass(name,body)",
	"\tDim found",
	"\tfound=\"\"",
	"\tFor Each key in VBClassBodies",
	"\t\tIf body=VBClassBodies.Item(key) Then",
	"\t\t\tfound=key",
	"\t\t\tExit For",
	"\t\tEnd If",
	"\tnext",
	"\tIf found=\"\" Then",
	"\t\tparseVB(\"Class \" + name + body)",
	"\t\tVBClassBodies.Add name, body",
	"\t\tfound=name",
	"\tEnd If",
	"\tfindOrDefineVBClass=found",
	"End Function"
	].join("\n"), "VBScript")
	function VBMediator(instance, accessors, name, value) {// jshint ignore:line
	var accessor = accessors[name]
	if (arguments.length === 4) {
	accessor.call(instance, value)
	} else {
	return accessor.call(instance)
	}
	}
	defineProperties = function (name, accessors, properties) {
	var className = "VBClass" + setTimeout("1"),// jshint ignore:line
	buffer = []
	buffer.push(
	"\r\n\tPrivate [__data__], [__proxy__]",
	"\tPublic Default Function [__const__](d, p)",
	"\t\tSet [__data__] = d: set [__proxy__] = p",
	"\t\tSet [__const__] = Me", //链式调用
	"\tEnd Function")
	//添加普通属性,因为VBScript对象不能像JS那样随意增删属性，必须在这里预先定义好
	for (name in properties) {
	if (!accessors.hasOwnProperty(name)) {
	buffer.push("\tPublic [" + name + "]")
	}
	}
	$$skipArray.forEach(function (name) {
	if (!accessors.hasOwnProperty(name)) {
	buffer.push("\tPublic [" + name + "]")
	}
	})
	buffer.push("\tPublic [" + 'hasOwnProperty' + "]")
	//添加访问器属性
	for (name in accessors) {
	buffer.push(
	//由于不知对方会传入什么,因此set, let都用上
	"\tPublic Property Let [" + name + "](val" + expose + ")", //setter
	"\t\tCall [__proxy__](Me,[__data__], \"" + name + "\", val" + expose + ")",
	"\tEnd Property",
	"\tPublic Property Set [" + name + "](val" + expose + ")", //setter
	"\t\tCall [__proxy__](Me,[__data__], \"" + name + "\", val" + expose + ")",
	"\tEnd Property",
	"\tPublic Property Get [" + name + "]", //getter
	"\tOn Error Resume Next", //必须优先使用set语句,否则它会误将数组当字符串返回
	"\t\tSet[" + name + "] = [__proxy__](Me,[__data__],\"" + name + "\")",
	"\tIf Err.Number <> 0 Then",
	"\t\t[" + name + "] = [__proxy__](Me,[__data__],\"" + name + "\")",
	"\tEnd If",
	"\tOn Error Goto 0",
	"\tEnd Property")

	}

	buffer.push("End Class")
	var code = buffer.join("\r\n"),
	realClassName = window['findOrDefineVBClass'](className, code) //如果该VB类已定义，返回类名。否则用className创建一个新类。
	if (realClassName === className) {
	window.parseVB([
	"Function " + className + "Factory(a, b)", //创建实例并传入两个关键的参数
	"\tDim o",
	"\tSet o = (New " + className + ")(a, b)",
	"\tSet " + className + "Factory = o",
	"End Function"
	].join("\r\n"))
	}
	var ret = window[realClassName + "Factory"](accessors, VBMediator) //得到其产品
	return ret //得到其产品
	}
	}
	}
	</script>
	</body>
	</html>