Update search parameter

gistfile1.js

/**
 * Update the param value of the passed URI.
 * In case parameter wasn't found we have to add it.
 * @param {string} uri - URI.
 * @param {string} key - Parameter name.
 * @param {string} value - Parameter value.
 * @returns {string} Updated URI.
 */
var updateQueryStringParameter = function (uri, key, value) {
    var re = new RegExp('([?&])' + key + '=.*?(&|$)', 'i');
    var hasSearch = uri.indexOf('?') !== -1;
    var separator = hasSearch ? '&' : '?';
    if (uri.match(re)) {
        return uri.replace(re, '$1' + key + '=' + value + '$2');
    } else {
        var split = uri.split('#');
        var hash = split[1];
        return split[0] + separator + key + '=' + value + (hash ? '#' + hash : '');
    }
}