Add query args to url

add_query_args.js

  /**
   * Add query args
   */
  function add_query_args(uri, params) {
    var separator = uri.indexOf('?') !== -1 ? '&' : '?';
    for (var key in params) {
      if(params.hasOwnProperty(key)){
        uri += separator + key + '=' + params[key];
        separator = '&';
      }
    }
    return uri;
  }