firebase - How do I save data from cloud firestore to a variable in swift?

Question

I want to save a particular field from a document into a variable. My code so far:

func getDocument(path: String, field: String? = "nil") -> some Any{
    var returnVar : Any = "DEFAULT VAL"
    var db: Firestore!
    db = Firestore.firestore()
    
    let docRef = db.document(path)
    docRef.getDocument { (document, error) in
        if let document = document, document.exists {
            if(field != "nil"){
                let property =  document.get("phrase") ?? "nil"
                returnVar = property
                return;
            }
            else{
                let dataDescription = document.data().map(String.init(describing:)) ?? "nil"
                returnVar = dataDescription
                return;
            }
        } else {
            print("Document does not exist")
            returnVar = -1
            return;
        }
    }
    print("Returned val: " + (returnVar as! String))
    return returnVar;
}

It seems however that my getDocument method returns before ever reading the data from firebase(coming from pure OOP land, I have no clue how this even happens) From debugging, it seems execution simply skips over the entire docRef.getDocument code and jumps to the return statement. It is only after the function returns does the code in the docRef.getDocument block get executed(what? how does code in a function that has already returned continue to execute?).

How can I store a particular field in a variable and return it?

Answer 1

Waitting for answers