JS 实现Json查询的方法实例

曾经看过一个大牛写的实现Json的一个模板类，今天突然没事就来自己试着写写。还好，一些东西还记得，思路还算清晰。直接上代码了

id="cproIframe_u1892994_2" width="580" height="90" src="http://pos.baidu.com/acom?adn=3&at=231&aurl=&cad=1&ccd=24&cec=GBK&cfv=18&ch=0&col=zh-CN&conBW=0&conOP=1&cpa=1&dai=2&dis=0&ltr=http%3A%2F%2Fwww.baidu.com%2Flink%3Furl%3DQx-mCTsY1CeZg8oE0KNaOgYSMZavaewWS6BmxMf0v4c4btsVXBoblXV3STbuYVxb%26wd%3D%26eqid%3Da2a9b922000176fe0000000455a4b469&ltu=http%3A%2F%2Fwww.jb51.net%2Farticle%2F35510.htm&lu_161=0&lunum=6&n=jb51_cpr&pcs=1263x635&pis=10000x10000&ps=516x166&psr=1280x720&pss=1263x517&qn=5bb6ddfc5701407c&rad=&rsi0=580&rsi1=90&rsi5=4&rss0=%23FFFFFF&rss1=%23F7FCFF&rss2=%230000ff&rss3=%23444444&rss4=%23008000&rss5=&rss6=%23e10900&rss7=&scale=&skin=tabcloud_skin_3&stid=5&td_id=1892994&titFF=%E5%AE%8B%E4%BD%93&titFS=12&titTA=left&tn=text_default_580_90&tpr=1436857372156&ts=1&version=2.0&xuanting=0&dtm=BAIDU_DUP2_SETJSONADSLOT&dc=2&di=u1892994&ti=JS%20%E5%AE%9E%E7%8E%B0Json%E6%9F%A5%E8%AF%A2%E7%9A%84%E6%96%B9%E6%B3%95%E5%AE%9E%E4%BE%8B_javascript%E6%8A%80%E5%B7%A7_%E8%84%9A%E6%9C%AC%E4%B9%8B%E5%AE%B6&tt=1436857372145.1022.1372.1372" align="center,center" marginwidth="0" marginheight="0" scrolling="no" frameborder="0" allowtransparency="true">

     其实很简单，我这部分代码，前一部分是简单的实现如何使用JS写模板，第二个就是具体的实现了JSON查询的一个扩展。

     以后查询Json就有了利器了。

复制代码代码如下:

/*
         * 定义模板函数
        */
        var template = function (queryArr) {

            var count = 0;

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

                var e = queryArr[i];

                if ($express) {
                    count++;
                }
            }

            return count;
        }

        /*
         * 模板创建函数
        */
        var createIntance = function (exp) {
            var fun = template.toString().replace("$express", exp).toString();
            return eval("0," + fun);
        }

        var testTodo = function () {

            var testArr = [
                { name: "张三", age: 20 },
                { name: "李四", age: 25 },
                { name: "王二麻子", age: 28 },
                { name: "小张", age: 30 }
            ];

            var func = createIntance("e.age>=25");

            alert(func(testArr));
        }

        /****************** JS 实现 JSON查询 **********************/

        // 定义常用的函数
        var len = function (s) { return s.length; }
        var left = function (s, n) { return s.substr(0, n); }
        var right = function (s, n) { return s.substr(-n); }
        var index = function (s, find) { return s.indexOf(find) + 1; }

        // 扩展原型方法
        var _proto = Object.prototype;

        // 缓存,解决快速查找
        var _cache = {};

        // 扩展运算符
        var _alias = [
            /@/g, "_e.",
            /AND/gi, "&&",
            /OR/gi, "||",
            /<>/g, "!=",
            /NOT/gi, "!",
            /([^=<>])=([^=]|$)/g, '$1==$2'
        ];

        var _rQuote = /""/g;
        var _rQuoteTemp = /!~/g;

        // 编译
        var _complite = function (code) {
            return eval("0," + code);
        }

        // 将扩展符号转换成标准的JS符号
        var _interpret = function (exp) {
            exp = exp.replace(_rQuote,"!~");
            var arr = exp.split('"');
            var i, n = arr.length;
            var k = _alias.length;

            for (var i = 0; i < n; i += 2) {
                var s = arr[i];
                for (var j = 0; j < k; j += 2) {
                    if (index(s, _alias[j]) > -1) {
                        s = s.replace(_alias[j], _alias[j + 1]);
                    }
                }
                arr[i] = s;
            }

            for (var i = 1; i < n; i += 2) {
                arr[i] = arr[i].replace(_rQuoteTemp, '\\"');
            }
            return arr.join('"');
        }

        // 定义模函数
        var _templ = function (_list) {
            var _ret = [];
            var _i = -1;

            for (var _k in _list) {
                var _e = _list[_k];
                if (_e != _proto[_k]) {
                    if ($C) {
                        _ret[++_i] = _e;
                    }
                }
            }
            return _ret;
        } .toString();

        // 扩展查询的方法
        _proto.Query = function (exp) {
            if (!exp) {
                return [];
            }

            var fn = _cache[exp];

            try {
                if (!fn) {
                    var code = _interpret(exp);
                    code = _templ.replace("$C", code);
                    fn = _cache[exp] = _complite(code);
                }
                return fn(this);
            } catch (e) {
                return [];
            }
        }

        var doTest = function () {

            var heros = [
            // 名============攻=====防=======力量====敏捷=====智力====
                {name: '冰室女巫', DP: 38, AP: 1.3, Str: 16, Dex: 16, Int: 21 },
                { name: '沉默术士', DP: 39, AP: 1.1, Str: 17, Dex: 16, Int: 21 },
                { name: '娜迦海妖', DP: 51, AP: 6.0, Str: 21, Dex: 21, Int: 18 },
                { name: '赏金猎人', DP: 39, AP: 4.0, Str: 17, Dex: 21, Int: 16 },
                { name: '剧毒术士', DP: 45, AP: 3.1, Str: 18, Dex: 22, Int: 15 },
                { name: '光之守卫', DP: 38, AP: 1.1, Str: 16, Dex: 15, Int: 22 },
                { name: '炼金术士', DP: 49, AP: 0.6, Str: 25, Dex: 11, Int: 25 }
            //...
            ];

            var match = heros.Query('@Str>20 AND @Dex>20');
            ShowResult(match[0]);

            // 查询：“士”结尾的
            // 结果：沉默术士,剧毒术士,炼金术士
            var match = heros.Query('right(@name,1)="士"');
            ShowResult(match[0]);
        }

        function ShowResult(result) {
            alert(result.name + " " + result.DP + " " + result.AP + " " + result.Str + " " + result.Dex + " " + result.Int);
        }

     代码就是这样了。欢迎大家拍砖，或者可以提出新的想法。我们一起来扩展