JSON Minification

JSONKeyMinify.js

var JSONKeyMinify = function (Array, JSON, undefined) {
    "use strict";
    // http://stackoverflow.com/questions/1988349/array-push-if-does-not-exist
    // http://stackoverflow.com/questions/4433402/replace-keys-json-in-javascript
    Array.prototype.inArray = function (comparer) {
        for (var i = 0; i < this.length; i++) {
            if (comparer(this[i])) return true;
        }
        return false;
    };
    Array.prototype.pushIfNotExist = function (element, comparer) {
        if (!this.inArray(comparer)) {
            this.push(element);
        }
    };
    var _keys = [],
        extractKeys = function (obj) {
            if (typeof obj === 'object') {
                for (var key in obj) {
                    if (!Array.isArray(obj)) {
                        _keys.pushIfNotExist(key, function (e) {
                            return e === key;
                        });
                    }
                    extractKeys(obj[key]);
                }
            }
        },
        encode = function (obj) {
            if (typeof obj !== 'object') return obj;
            for (var prop in obj) {
                if (!Array.isArray(obj)) {
                    if (obj.hasOwnProperty(prop)) {
                        obj[_keys.indexOf(prop)] = encode(obj[prop]);
                        delete obj[prop];
                    }
                } else {
                    obj[prop] = encode(obj[prop]);
                }
            }
            return obj;
        },
        decode = function (obj) {
            if (typeof obj !== 'object') return obj;
            for (var prop in obj) {
                if (!Array.isArray(obj)) {
                    if (obj.hasOwnProperty(prop)) {
                        obj[_keys[prop]] = decode(obj[prop]);
                        delete obj[prop];
                    }
                } else {
                    obj[prop] = decode(obj[prop]);
                }
            }
            return obj;
        },
        minify = function (json) {
            extractKeys(json);
            return { JKMKeys:_keys, JKMValues:encode(json) };
        },
        expand = function (minifiedJson) {
            _keys = minifiedJson.JKMKeys;
            return decode(minifiedJson.JKMValues);
        };
    return {
        minify:minify,
        expand:expand
    };
}(Array, JSON);