how to setstate after saga async request

Question

I'm using redux-saga in my project. I used redux-thunk before, so i can't setState ends of some async request. like

this.props.thunkAsync()
  .then(){
    this.setState({ '' });
  }

Since thunk returns promise, i could use 'then'. But i can't do this with saga, because saga doesn't return promise. So i did it in componentWillReceiveProps by checking flag props (like REQUEST_SUCCESS,REQUEST_WAITING...) has been changed. I think it's not good way to solve this problem.

So.. My question is how can i do some works when async request ends in redux-saga!

Answer 1

Every api call you make is processed as an async request but handled using a generator function in a saga.

So, After a successful api call, you can do the following possible things.

1. Make another api call like

function* onLogin(action) {
  try {
    const { userName, password } = action;
    const response = yield call(LoginService.login, userName, password);
    yield put(LoginService.loginSuccess(response.user.id));
    const branchDetails = yield call(ProfileService.fetchBranchDetails, response.user.user_type_id);
    yield put(ProfileActions.fetchBranchDetailsSuccess(branchDetails));
  } catch (error) {
    yield put(ProfileActions.fetchUserDetailsError(error));
  }
}

2. Pass a Callback after successfull api

   onLoginClick() {
     const { userName, password } = this.state;
     this.props.login(userName, password, this.onLoginSuccess);
   }
   
   onLoginSuccess(userDetails) {
     this.setState({ userDetails });
   }
   
   function *onLogin(action) {
     try {
        const { userName, password, onLoginSuccess } = action;
        const response = yield call(LoginService.login, userName, password);
        if (onLoginSuccess) {
            onLoginSuccess(response);
        }
   
        yield put(LoginService.loginSuccess(response.user.id));
        const branchDetails = yield call(ProfileService.fetchBranchDetails, 
        response.user.user_type_id);
        yield put(ProfileActions.fetchBranchDetailsSuccess(branchDetails));
    } catch (error) {
        yield put(ProfileActions.fetchUserDetailsError(error));
    }
   

   }

3. Update Reducer State and get from props by mapStateToProps

   yield put(LoginService.loginSuccess(response.user.id));        
   @connect(
       state => ({
           usedDetails: state.user.get('usedDetails'),
       })
   )
   static getDerivedStateFromProps(nextProps, prevState) {
       const { usedDetails } = nextProps;
       return {
           usedDetails
       }
   }