querystring.js

(function(window) {
	var _queryString = {};

	/**
	 * IFFE function to parse query string and store values in _queryString
	 * pulled search regex from the page below: /([^&=]+)=?([^&]*)/g
	 * @see http://stackoverflow.com/questions/901115/how-can-i-get-query-string-values-in-javascript
	 *
	 * @param  {String} currentUrl
	 */
	(function(currentUrl){
		var query = currentUrl.split('?')[1] || '',
			search = /([^&=]+)=?([^&]*)/g,
			paramParts;

		for(paramParts = search.exec(query); paramParts; paramParts = search.exec(query)) {
			_queryString[paramParts[1]] = decodeURIComponent(paramParts[2].replace(/\+/g, ' '));
		}
	}(window.location.href));

	/**
	 * Accessor method to retrieve querystring values or the entire set of values
	 * @param  {String} name
	 * @return {Mixed}	Returns the value of the named parameter passed in, or null.
	 * 					If called with nothing passed in, it returns the entire _queryString object
	 */
	var querystring = function querystring(name) {
		if(arguments.length > 0) {
			if(typeof name === 'string') {
				return (_queryString.hasOwnProperty(name)) ? _queryString[name] : null;
			}else{
				throw "The parameter name must be a string";
			}
		}
		return _queryString;
	};

	window.querystring = querystring;

}(window, undefined));