jQuery.url = function(){
    var segments = {};
    
    var parsed = {};
    
    /**
     * Options object. Only the URI and strictMode values can be changed via the setters below.
     */
    var options = {
    
        url: window.location, // default URI is the page in which the script is running
        strictMode: false, // 'loose' parsing by default
        key: ["source", "protocol", "authority", "userInfo", "user", "password", "host", "port", "relative", "path", "directory", "file", "query", "anchor"], // keys available to query 
        q: {
            name: "queryKey",
            parser: /(?:^|&)([^&=]*)=?([^&]*)/g
        },
        
        parser: {
            strict: /^(?:([^:\/?#]+):)?(?:\/\/((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?))?((((?:[^?#\/]*\/)*)([^?#]*))(?:\?([^#]*))?(?:#(.*))?)/, // more intuitive, fails on relative paths and deviates from specs
            loose: /^(?:(?![^:@]+:[^:@\/]*@)([^:\/?#.]+):)?(?:\/\/)?((?:(([^:@]*):?([^:@]*))?@)?([^:\/?#]*)(?::(\d*))?)(((\/(?:[^?#](?![^?#\/]*\.[^?#\/.]+(?:[?#]|$)))*\/?)?([^?#\/]*))(?:\?([^#]*))?(?:#(.*))?)/ //less intuitive, more accurate to the specs
        }
    
    };
    
    /**
     * Deals with the parsing of the URI according to the regex above.
     * Written by Steven Levithan - see credits at top.
     */
    var parseUri = function(){
        str = decodeURI(options.url);
        
        var m = options.parser[options.strictMode ? "strict" : "loose"].exec(str);
        var uri = {};
        var i = 14;
        
        while (i--) {
            uri[options.key[i]] = m[i] || "";
        }
        
        uri[options.q.name] = {};
        uri[options.key[12]].replace(options.q.parser, function($0, $1, $2){
            if ($1) {
                uri[options.q.name][$1] = $2;
            }
        });
        
        return uri;
    };
    
    /**
     * Returns the value of the passed in key from the parsed URI.
     *
     * @param string key The key whose value is required
     */
    var key = function(key){
        if (!parsed.length) {
            setUp(); // if the URI has not been parsed yet then do this first...	
        }
        if (key == "base") {
            if (parsed.port !== null && parsed.port !== "") {
                return parsed.protocol + "://" + parsed.host + ":" + parsed.port + "/";
            }
            else {
                return parsed.protocol + "://" + parsed.host + "/";
            }
        }
        
        return (parsed[key] === "") ? null : parsed[key];
    };
    
    /**
     * Returns the value of the required query string parameter.
     *
     * @param string item The parameter whose value is required
     */
    var param = function(item){
        if (!parsed.length) {
            setUp(); // if the URI has not been parsed yet then do this first...	
        }
        return (parsed.queryKey[item] === null) ? null : parsed.queryKey[item];
    };
    
    /**
     * 'Constructor' (not really!) function.
     *  Called whenever the URI changes to kick off re-parsing of the URI and splitting it up into segments.
     */
    var setUp = function(){
        parsed = parseUri();
        
        getSegments();
    };
    
    /**
     * Splits up the body of the URI into segments (i.e. sections delimited by '/')
     */
    var getSegments = function(){
        var p = parsed.path;
        segments = []; // clear out segments array
        segments = parsed.path.length == 1 ? {} : (p.charAt(p.length - 1) == "/" ? p.substring(1, p.length - 1) : path = p.substring(1)).split("/");
    };
    
    return {
    
        /**
         * Sets the parsing mode - either strict or loose. Set to loose by default.
         *
         * @param string mode The mode to set the parser to. Anything apart from a value of 'strict' will set it to loose!
         */
        setMode: function(mode){
            strictMode = mode == "strict" ? true : false;
            return this;
        },
        
        /**
         * Sets URI to parse if you don't want to to parse the current page's URI.
         * Calling the function with no value for newUri resets it to the current page's URI.
         *
         * @param string newUri The URI to parse.
         */
        setUrl: function(newUri){
            options.url = newUri === undefined ? window.location : newUri;
            setUp();
            return this;
        },
        
        /**
         * Returns the value of the specified URI segment. Segments are numbered from 1 to the number of segments.
         * For example the URI http://test.com/about/company/ segment(1) would return 'about'.
         *
         * If no integer is passed into the function it returns the number of segments in the URI.
         *
         * @param int pos The position of the segment to return. Can be empty.
         */
        segment: function(pos){
            if (!parsed.length) {
                setUp(); // if the URI has not been parsed yet then do this first...	
            }
            if (pos === undefined) {
                return segments.length;
            }
            return (segments[pos] === "" || segments[pos] === undefined) ? null : segments[pos];
        },
        
        attr: key, // provides public access to private 'key' function - see above
        param: param // provides public access to private 'param' function - see above
    };
    
}();