CODEWITHSUNDEEP
javascriptreact-nativeasync-awaitasyncstorage
Anks
Anks

Reputation: 69

Not able to get value from Async function which returns value by calling asyncStorage function

In _retrieveSelectedBusNumber i'm returning value of selectedBusNumber by calling asyncStorage. In TaskManager.defineTask I want to retrieve the selectedBusNumber value, but currently I'm receiving a promise. 

  try {
    const value = await AsyncStorage.getItem("selectedBusNumber").then(
      data => data
    );
    if (value !== null) {
      console.log(value, "value");
      return value;
    }
  } catch (error) {
    console.log("error");
    console.log(error);
  }
};


TaskManager.defineTask(FETCH_LOCATION_TASK, ({ data, error }) => {
  if (error) {
    console.log("Error in fetch location from fetch_location_task");
    return;
  }
  if (data) {
    const location = data;
    console.log(location);
    var database = firebase.database();
    let selectedBusNumber = _retrieveSelectedBusNumber().then(data => data);

    //below console returns ----> Promise {_40: 0, _65: 0, _55: null, _72: null} "_retrieveSelectedBusNumber()" <----

    console.log(selectedBusNumber, "_retrieveSelectedBusNumber()");
    const busNumber = async () =>
      await _retrieveSelectedBusNumber().then(data => data);
//below console returns ---> ƒ busNumber() <----    
console.log(busNumber, "busnumber");
  }
});

I expect to retrieve selectedBusNumber value using _retrieveSelectedBusNumber.

Upvotes: 2

Views: 118

Answers (2)

deathstroke
deathstroke

Reputation: 603

Your function to fetch from AsyncStorage should look like this

 async GetLocalStorage(key){
        try {
    const value = await AsyncStorage.getItem("selectedBusNumber");
    if (value !== null) {
      console.log(value, "value");
      return value;
    }
  } catch (error) {
     console.log("error");
     console.log(error);
      }
     };
    }

Upvotes: 0

B M
B M

Reputation: 4019

There is a lot to be improved in this code, but the main problem is the line below:

    let selectedBusNumber = _retrieveSelectedBusNumber().then(data => data);

You need to await the data from the promise:

    let selectedBusNumber = await _retrieveSelectedBusNumber();

For that to work you also need to add an async in front of your defineTask callback. Also .then(data => data) is without any effect, you can remove it.

Upvotes: 2

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