url.js

/**
 * Patterns URL - URL parsing utilities
 *
 * Copyright 2013 Simplon B.V.
 */

function UrlArgumentParser() {
    this._cache = null;
    if (window.addEventListener) window.addEventListener("popstate", this._reset);
}

UrlArgumentParser.prototype = {
    space_pattern: /\+/g,
    keyvalue_pattern: /^(.+?)(?:=(.*))/,

    _reset: function UrlArgumentParser_reset() {
        this._cache = null;
    },

    _decodeQS: function UrlArgumentParser_decodeQS(bit) {
        return decodeURIComponent(bit.replace(this.space_pattern, " "));
    },

    _parse: function UrlArgumentParser_parse(qs) {
        var query = /\?(.+)/.exec(qs),
            params = {};

        if (query === null) return params;

        var parameters = query[1].split("&"),
            i,
            parts,
            key,
            value;

        for (i = 0; i < parameters.length; i++) {
            if ((parts = this.keyvalue_pattern.exec(parameters[i])) === null) {
                key = this._decodeQS(parameters[i]);
                value = null;
            } else {
                key = this._decodeQS(parts[1]);
                value = this._decodeQS(parts[2]);
            }

            if (params[key] === undefined) params[key] = [];
            params[key].push(value);
        }

        return params;
    },

    get: function UrlArgumentParser_get() {
        if (this._cache === null) this._cache = this._parse(window.location.search);
        return this._cache;
    },
};

var url_parser = new UrlArgumentParser();

export default {
    UrlArgumentParser: UrlArgumentParser,
    parameters: url_parser.get.bind(url_parser),
};