URI.Query

gistfile1.js

function foreach (arry, func) {
    var i = 0, len = arry.length;
    if (len) {
        for (; i < len; i += 1) {
            func(arry[i], i);
        }
    }
}

Array.prototype.foreach = function (func) {
    foreach.apply(null, [ this, func ]);
};

function test (resFunc, forecast) {
    resFunc  = (typeof resFunc === 'string')  ? resFunc  : JSON.stringify(resFunc);
    forecast = (typeof forecast === 'string') ? forecast : JSON.stringify(forecast);

    console.log(
      (resFunc == forecast)
        ? [ 'success: ', resFunc ].join('')
        : [ '!failed: ', resFunc, forecast].join(' --- ')
    );
}

function Query () {};
(function (Q) {
    Q.parse = function (str, type) {
        type = type || 'HASH';
        type = (type.match(/^array$/i)) ? 'ARRAY' : 'HASH';

        if (! str) return (type === 'ARRAY') ? [] : {};

        if (typeof str !== 'string') return { error: 'failed: 1st argument must be "string"' };

        str = (str.match(/^\?/)) ? str.slice(1) : str;

        var obj, buf;

        if (type === 'ARRAY') {
            obj = [];
            (str.split(/&/)).foreach(function (keyVal) {
                buf = keyVal.split(/=/);
                obj.push([ buf[0], decodeURIComponent(buf[1]) ]);
            });
            return obj;
        }

        if (type === 'HASH') {
            obj = {};
            (str.split(/&/)).foreach(function (keyVal) {
                buf = keyVal.split(/=/);
                obj[ buf[0] ] = decodeURIComponent(buf[1]);
            });
            return obj;
        }
    };

    Q.stringify = function (obj) {
        if (! obj) return null; // '';

        if (typeof obj === 'string') return obj;

        var buf = [];

        if (obj instanceof Array) {
            obj.foreach(function (keyVal) {
                buf.push([ keyVal[0], encodeURIComponent(keyVal[1]) ].join('='));
            });
            return (buf.length > 0) ? buf.join('&') : null;
        }

        if (typeof obj === 'object') {
            for (var key in obj) {
                buf.push([ key, encodeURIComponent(obj[key]) ].join('='));
            }
            return (buf.length > 0) ? buf.join('&') : null;
        }

        return { error: 'failed: arguments must be "hash" or "array"' };
    };
}) (Query.prototype);

var QUERY = new Query;

test(QUERY.parse(), {});
test(QUERY.parse(null), {});
test(QUERY.parse(""), {});
test(QUERY.parse(undefined), {});
test(QUERY.parse({}), { error: 'failed: 1st argument must be "string"' });

var _array = 'array';
test(QUERY.parse(null, _array), []);
test(QUERY.parse("", _array), []);
test(QUERY.parse(undefined, _array), []);

var japStr = 'ミッちょん みちこ';
test(QUERY.parse("mode=tora&q=" + encodeURIComponent(japStr)), { mode : "tora", q : japStr });
test(QUERY.parse("?mode=tora&q=" + encodeURIComponent(japStr), _array), [ [ "mode" , "tora" ], ["q" , japStr ] ]);

console.log("---------------");

test(QUERY.stringify(), null);
test(QUERY.stringify(""), null);
test(QUERY.stringify({}), null);
test(QUERY.stringify([]), null);

test(QUERY.stringify({ mode : 'gaw', val : 'karipaku'}), "mode=gaw&val=karipaku");
test(QUERY.stringify([ [ "mode", "vow" ], [ "val", "wow" ] ]), "mode=vow&val=wow");