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JavaScript函数命名空间、参数类型重载实现

时间:2014-09-06 09:41:42      阅读:409      评论:0      收藏:0      [点我收藏+]

标签:style   http   os   io   使用   java   ar   for   art   

有时候使用doFunc({arg1: xxx, arg2:xxx});不方便,还是得在参数表重载,而重载情况又多种多样弄得晕头转向,结果就试着写了这么个东西,也不知道有没有地方能用上:

 

<!DOCTYPE html>
<html lang="zh">
<head>
    <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
    <title>命名空间、参数类型重载</title>
    <script type="text/javascript" src="arg-func.js"></script>
    <script type="text/javascript">
        (function () {
            var MyFuncs = {
                ‘myNamespace.exampleFunc(string str, number num)‘: function (str, num) {
                    alert(‘str: ‘ + str + ‘ num: ‘ + num);
                },
                ‘myNamespace.exampleFunc(number num)‘: function (num) {
                    alert(‘num: ‘ + num);
                },
                ‘myNamespace.exampleFunc(array)‘: function (arr) {
                    alert(‘arr: ‘ + arr);
                },
                ‘myNamespace.exampleFunc()‘: function () {
                    alert(‘无参数重载‘);
                }
            };

            ArgFunc.parse(MyFuncs);
        })();
    </script>
</head>
<body>
    <label>有效调用:</label><br />
    <input type="button" value="myNamespace.exampleFunc(‘abc‘,123)" onclick="myNamespace.exampleFunc(‘abc‘, 123)" /><br />
    <input type="button" value="myNamespace.exampleFunc(123)" onclick="myNamespace.exampleFunc(123)" /><br />
    <input type="button" value="myNamespace.exampleFunc([1,2,3])" onclick="myNamespace.exampleFunc([1, 2, 3])" /><br />
    <input type="button" value="myNamespace.exampleFunc()" onclick="myNamespace.exampleFunc()" /><br />
    <label>无效调用:</label><br />
    <input type="button" value="myNamespace.exampleFunc(false)" onclick="myNamespace.exampleFunc(false)" /><br />
    <input type="button" value="myNamespace.exampleFunc(‘abc‘,123,[1,2,3])" onclick="myNamespace.exampleFunc(‘abc‘, 123, [1, 2, 3])" /><br />
</body>
</html>

 

用到的arg-func.js:

(function () {
    if (!String.prototype.trim) {
        String.prototype.trim = function () {
            return this.replace(/(^\s+)|(\s+$)/g, ‘‘);
        };
    }

    var TYPE = { UNKOWN: null, UNDEFINED: ‘undefined‘, NULL: ‘null‘, BOOLEAN: ‘boolean‘, NUMBER: ‘number‘, STRING: ‘string‘, FUNCTION: ‘function‘, OBJECT: ‘object‘, ARRAY: ‘array‘ };
    function getType(o) {
        if (o === undefined) { return TYPE.UNDEFINED; }
        if (o === null) { return TYPE.NULL; }
        switch (typeof (o)) {
            case TYPE.BOOLEAN: return TYPE.BOOLEAN;
            case TYPE.NUMBER: return TYPE.NUMBER;
            case TYPE.STRING: return TYPE.STRING;
            case TYPE.FUNCTION: return TYPE.FUNCTION;
        }
        switch (Object.prototype.toString.call(o)) {
            case ‘[object Array]‘: return TYPE.ARRAY;
            case ‘[object Object]‘: return TYPE.OBJECT;
            default: return o ? TYPE.OBJECT : TYPE.UNKOWN;
        }
    }

    var _ArgFunc = {
        _parse: function (format, func, namespace) {
            var lp = format.indexOf(‘(‘), rp = format.indexOf(‘)‘);
            var name = format.substring(0, lp);
            var argTypes = format.substring(lp + 1, rp).split(‘,‘);
            for (var i = 0, len = argTypes.length; i < len; i++) {
                argTypes[i] = argTypes[i].trim().split(/ +/)[0];
            }
            argTypes = argTypes.join(‘,‘);

            var nsnn = _ArgFunc._analyseNamespace(name, namespace);
            namespace = nsnn.namespace;
            name = nsnn.name;

            var wrapperFunc = namespace[name];
            if (!wrapperFunc) {
                wrapperFunc = namespace[name] = function () {
                    ArgFunc.apply(wrapperFunc, arguments);
                };
            }

            if (wrapperFunc[argTypes]) {
                throw ‘方法已存在参数类型一样的重载。‘;
            } else {
                wrapperFunc[argTypes] = func;
            }
        },
        _analyseNamespace: function (name, upperNamespace) {
            var namespace = upperNamespace || window;
            var parts = name.split(‘.‘);
            var name = parts.pop();
            for (var i = 0, part; part = parts[i]; i++) {
                if (!namespace[part]) {
                    namespace[part] = {};
                }
                namespace = namespace[part];
            }
            return { namespace: namespace, name: name };
        }
    };



    var ArgFunc = {
        bind: function (funcs, prototype) {
            ArgFunc.parse(funcs, prototype);
        },
        parse: function (funcs, namespace) {
            if (arguments.length == 3) {
                _ArgFunc._parse(arguments[0], arguments[1], arguments[2]);
            } else if (getType(funcs) == TYPE.OBJECT) {
                for (var format in funcs) {
                    _ArgFunc._parse(format, funcs[format], namespace);
                }
            } else if (getType(funcs) = TYPE.ARRAY) {
                for (var i = 0, func; func = funcs[i]; i++) {
                    _ArgFunc._parse(func[0], func[1], namespace);
                }
            }
        },
        apply: function (func, args) {
            var argTypes = [];
            for (var i = 0, len = args.length; i < len; i++) {
                var arg = args[i];
                argTypes.push(getType(arg));
            }
            argTypes = argTypes.join(‘,‘);

            func = func[argTypes];
            if (!func) {
                throw ‘没有找到参数类型匹配的重载方法‘;
            } else {
                func.apply(this, args);
            }
        }
    };
    if (!window[‘ArgFunc‘]) {
        window[‘ArgFunc‘] = ArgFunc;
    }
})();

JavaScript函数命名空间、参数类型重载实现

标签:style   http   os   io   使用   java   ar   for   art   

原文地址:http://www.cnblogs.com/dashublog/p/3959136.html

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