Best way to retrieve Firebase data and return it, or an alternative way

Question

I am using Firebase for some projects and am liking the platform a lot.

I just stumbled upon a thing that I could not do and was wondering if there was any way to a

Answer 1

To separate the code out, you'd pass in a callback:

function getTwoLatestLocations(callback)
{
    var twoLocations;
    myFirebaseRef.limitToLast(2).once('value', function (dataSnapshot) {
        twoLocations = dataSnapshot.val();
        callback(twoLocations);
    }, function (errorObject) {
        // code to handle read error
        console.log("The read failed: " + errorObject.code);
    });

}

And then calling it like this:

function someCalcutationsWithTheTwoLastLocations()
{
    getTwoLatestLocations(function(twoLocations) {
        // Do some calculations
    });
}

The important thing to always remember is that you cannot wait for something that is loaded asynchronously.

This has been covered quite a few times, including in this top answer from the list of related questions: Handling Asynchronous Calls (Firebase) in functions