How can i write data that is coming from Firebase to store quickly?

Question

Firstly, I\'m working with React Native. I\'m getting a data from Firebase and want to write to store (by Redux) quickly. But It doesn\'t work. You can find my all of codes

Answer 1

The thing is: - You're using both async/await, and then/catch in your code. - you're calling getSelectedGroupDetail before your async code resolves.

Fast Solution

getTumData =  (uid) => {

    const {selectedGroupDetail, getSelectedGroupDetail} = this.props;
    var yeniGrupDetayi = {};
    firebase.database().ref("/groups/"+uid).once('value').then(
     (snapshot) => {
        yeniGrupDetayi = {...snapshot.val(), uid: uid};
        this.props.getSelectedGroupDetail(yeniGrupDetayi);
      }).catch(e => console.log(e.message));   
  };

Better Solution:

1st: use Redux-Thunk middleware. 2nd: Move your Async code into your action creator: I mean this

async getTumData (uid) {

    const {selectedGroupDetail, getSelectedGroupDetail} = this.props;
    var yeniGrupDetayi = {};
    await firebase.database().ref("/groups/"+uid).once('value').then(
      function(snapshot){
        yeniGrupDetayi = {...snapshot.val(), uid: uid};
      }).catch(e => console.log(e.message));

      console.log("FONKSIYON ICERISINDEKI ITEM ==>", yeniGrupDetayi);
      this.props.getSelectedGroupDetail(yeniGrupDetayi);
      console.log("ACTION'DAN GELEN ITEM ===>", selectedGroupDetail);

  }

3rd: Your reducer should have another piece of data as an indicator for the time-gap before your selectedGroupDetail resolves:

// reducer initial state:
const INITIAL_STATE = { error: '', loading: false, selectedGroupDetail: null }

4th: Inside your action creator, you should dispatch 3 actions: ACTION_NAME_START // This should should only set loading to true in your reducer. ACTION_NAME_SUCCESS // set loading to false, and selectedGroupDetail to the new collection retured ACTION_NAME_FAIL // in case op failed set error

5th: Your React component, should display a loading indicator (spinner or somthing), and maybe disable FlatList button during the loading state.

// Action creator
export const myAction = () => (dispatch) => {
  dispatch({ type: ACTION_NAME_START });
  firebase.database().ref("/groups/"+uid).once('value').then(
  function(snapshot){
    yeniGrupDetayi = {...snapshot.val(), uid: uid};
    dispatch({ type: ACTION_NAME_SUCCESS, payload: yeniGrupDetayi  });

  }).catch(e => {
  dispatch({ type: ACTION_NAME_FAIL, payload: e.message });
});

};


// Reducer
const INITIAL_STATE = {
  loading: false,
  error: '',
  data: null,
};

export default (state = INITIAL_STATE, { type, payload }) => {
  switch (type) {
    case ACTION_NAME_START:
      return {
        ...state,
        error: '',
        loading: true,
        data: null,
      };

    case ACTION_NAME_SUCCESS:
      return {
        ...state,
        error: '',
        loading: false,
        data: payload,
      };

    case ACTION_NAME_FAIL:
      return {
        ...state,
        error: payload,
        loading: false,
        data: null,
      };

    default:
      return state;
  }
};