querystring.js

(function () {
	'use strict';
	var queryString = {};

	queryString.parse = function (str) {
		if (typeof str !== 'string') {
			return {};
		}

		str = str.trim().replace(/^(\?|#)/, '');

		if (!str) {
			return {};
		}

		return str.trim().split('&').reduce(function (ret, param) {
			var parts = param.replace(/\+/g, ' ').split('=');
			var key = parts[0];
			var val = parts[1];

			key = decodeURIComponent(key);
			// missing `=` should be `null`:
			// http://w3.org/TR/2012/WD-url-20120524/#collect-url-parameters
			val = val === undefined ? null : decodeURIComponent(val);

			if (!ret.hasOwnProperty(key)) {
				ret[key] = val;
			} else if (Array.isArray(ret[key])) {
				ret[key].push(val);
			} else {
				ret[key] = [ret[key], val];
			}

			return ret;
		}, {});
	};

	queryString.stringify = function (obj) {
		return obj ? Object.keys(obj).map(function (key) {
			var val = obj[key];

			if (Array.isArray(val)) {
				return val.map(function (val2) {
					return encodeURIComponent(key) + '=' + encodeURIComponent(val2);
				}).join('&');
			}

			return encodeURIComponent(key) + '=' + encodeURIComponent(val);
		}).join('&') : '';
	};

	if (typeof define === 'function' && define.amd) {
		define(function() { return queryString; });
	} else if (typeof module !== 'undefined' && module.exports) {
		module.exports = queryString;
	} else {
		window.queryString = queryString;
	}
})();