Failing actions

gistfile1.js

var UsersStore = Marty.createStore({
  handlers: {
    addUser: [UserConstants.ADD_USER, UserConstants.CREATE_USER]
  },
  addUser: function (user) {
    this.state[user.id] = user;
    this.hasChanged();

    return function actionFailed(error) {
      this.state.errors[user.id] = error;
      delete this.state[user.id];
      this.hasChanged();
    }
  }
});

var UserActionCreators = Marty.createActionCreators({
  createUser: UserConstants.CREATE_USER(function (user) {
    var action = this.dispatch(user);

    //actionFailed will be called if
    //you throw Error();
    //or call action.rollback();
    //or this promise is rejected
    return UserAPI.createUser(user);
  })
});