Can't update state after reloading the app in react native firebase?

Question

I have some issues with Firebase in React Native.

I\'m tried to read the data from the Realtime database. I get the data from database and set them into the state an

Answer 1

I think your database listener should look more like this:

const providerRef = firebase.database().ref('providers');
providerRef.on('value', snapshot => {
    var newState = [];
    console.log(snapshot.val());
    snapshot.forEach((childSnapshot) => {
        newState.push({
            id: childSnapshot.val().id,
            username: childSnapshot.val().username,
            coordinates: {
                longitude: childSnapshot.val().coordinates.longitude,
                latitude: childSnapshot.val().coordinates.latitude,
            }
        });
    });
    this.setState({ providers: newState })
});

Changes from yours:

• Declare newState inside the callback, so that you start out with an empty array each time you get data from Firebase.
• Call setState(...) only after processing all data from the database, instead of after each item.