text: // Copyright 2014 The Oppia Authors. All Rights Reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //      http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS-IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  /**
   * @fileoverview Service for storing all generic functions which have to be
   * used at multiple places in the codebase.
   */
  
  oppia.factory('UtilsService', [function() {
    var utils = {
      isEmpty: function(obj) {
        for (var property in obj) {
          if (obj.hasOwnProperty(property)) {
            return false;
          }
        }
        return true;
      },
  
      // http://stackoverflow.com/questions/203739
      isString: function(input) {
        return (typeof input === 'string' || input instanceof String);
      }
    };
    return utils;
  }]);
  