File: querystring/js/querystring-parse.js

            /**
             * The QueryString module adds support for serializing JavaScript objects into
             * query strings and parsing JavaScript objects from query strings format.
             *
             * The QueryString namespace is added to your YUI instance including static methods
             * `Y.QueryString.parse(..)` and `Y.QueryString.stringify(..)`.
             *
             * The `querystring` module is a alias for `querystring-parse` and
             * `querystring-stringify`.
             *
             * As their names suggest, `querystring-parse` adds support for parsing
             * Query String data (`Y.QueryString.parse`) and `querystring-stringify` for serializing
             * JavaScript data into Query Strings (`Y.QueryString.stringify`).  You may choose to
             * include either of the submodules individually if you don't need the
             * complementary functionality, or include the rollup for both.
             *
             * @module querystring
             * @main querystring
            */
            
            /**
             * Provides Y.QueryString.parse method to accept Query Strings and return native
             * JavaScript objects.
             *
             * @module querystring
             * @submodule querystring-parse
            */
            
            /**
             * The QueryString module adds support for serializing JavaScript objects into
             * query strings and parsing JavaScript objects from query strings format.
             * @class QueryString
             * @static
             */
            var QueryString = Y.namespace("QueryString"),
            
            // Parse a key=val string.
            // These can get pretty hairy
            // example flow:
            // parse(foo[bar][][bla]=baz)
            // return parse(foo[bar][][bla],"baz")
            // return parse(foo[bar][], {bla : "baz"})
            // return parse(foo[bar], [{bla:"baz"}])
            // return parse(foo, {bar:[{bla:"baz"}]})
            // return {foo:{bar:[{bla:"baz"}]}}
            pieceParser = function (eq) {
                return function parsePiece (key, val) {
            
                    var sliced, numVal, head, tail, ret;
            
                    if (arguments.length !== 2) {
                        // key=val, called from the map/reduce
                        key = key.split(eq);
                        return parsePiece(
                            QueryString.unescape(key.shift()),
                            QueryString.unescape(key.join(eq))
                        );
                    }
                    key = key.replace(/^\s+|\s+$/g, '');
                    if (Y.Lang.isString(val)) {
                        val = val.replace(/^\s+|\s+$/g, '');
                        // convert numerals to numbers
                        if (!isNaN(val)) {
                            numVal = +val;
                            if (val === numVal.toString(10)) {
                                val = numVal;
                            }
                        }
                    }
                    sliced = /(.*)\[([^\]]*)\]$/.exec(key);
                    if (!sliced) {
                        ret = {};
                        if (key) {
                            ret[key] = val;
                        }
                        return ret;
                    }
                    // ["foo[][bar][][baz]", "foo[][bar][]", "baz"]
                    tail = sliced[2];
                    head = sliced[1];
            
                    // array: key[]=val
                    if (!tail) {
                        return parsePiece(head, [val]);
                    }
            
                    // obj: key[subkey]=val
                    ret = {};
                    ret[tail] = val;
                    return parsePiece(head, ret);
                };
            },
            
            // the reducer function that merges each query piece together into one set of params
            mergeParams = function(params, addition) {
                return (
                    // if it's uncontested, then just return the addition.
                    (!params) ? addition
                    // if the existing value is an array, then concat it.
                    : (Y.Lang.isArray(params)) ? params.concat(addition)
                    // if the existing value is not an array, and either are not objects, arrayify it.
                    : (!Y.Lang.isObject(params) || !Y.Lang.isObject(addition)) ? [params].concat(addition)
                    // else merge them as objects, which is a little more complex
                    : mergeObjects(params, addition)
                );
            },
            
            // Merge two *objects* together. If this is called, we've already ruled
            // out the simple cases, and need to do the for-in business.
            mergeObjects = function(params, addition) {
                for (var i in addition) {
                    if (i && addition.hasOwnProperty(i)) {
                        params[i] = mergeParams(params[i], addition[i]);
                    }
                }
                return params;
            };
            
            /**
             * Accept Query Strings and return native JavaScript objects.
             *
             * @method parse
             * @param qs {String} Querystring to be parsed into an object.
             * @param sep {String} (optional) Character that should join param k=v pairs together. Default: "&"
             * @param eq  {String} (optional) Character that should join keys to their values. Default: "="
             * @public
             * @static
             */
            QueryString.parse = function (qs, sep, eq) {
                // wouldn't Y.Array(qs.split()).map(pieceParser(eq)).reduce(mergeParams) be prettier?
                return Y.Array.reduce(
                    Y.Array.map(
                        qs.split(sep || "&"),
                        pieceParser(eq || "=")
                    ),
                    {},
                    mergeParams
                );
            };
            
            /**
             * Provides Y.QueryString.unescape method to be able to override default decoding
             * method.  This is important in cases where non-standard delimiters are used, if
             * the delimiters would not normally be handled properly by the builtin
             * (en|de)codeURIComponent functions.
             * Default: replace "+" with " ", and then decodeURIComponent behavior.
             *
             * @method unescape
             * @param s {String} String to be decoded.
             * @public
             * @static
             **/
            QueryString.unescape = function (s) {
                return decodeURIComponent(s.replace(/\+/g, ' '));
            };