Is there a way to return the ID value from this function? SWIFT IOS

Question

func runQuery() -> (String){
    appSyncClient?.fetch(query: ListTodosQuery(), cachePolicy: .returnCacheDataAndFetch) {(result, error) in
        if error != nil {
            print(error?.localizedDescription ?? "")
            return
        }
        print("Query complete.")
        result?.data?.listTodos?.items!.forEach { print(($0?.name)! + " " + ($0?.description)!) }
    }
    return the string
}

It is the AWS AMPLIFY tutorial code. It only prints out the result from the DB ($0?.name, etc...).

However, I want to return the value of $0?.name.

When I try to assign or set a var to bring the parameter out from the function.

It's either returns nothing or it does not allow me to return a value.

Any idea?

Answer 1

fetch method execute asynchronously. Asynchronous function can not return a result on function return.

Here I concatenate $0?.names and use blank space as separators.

func runQuery(completionHandler: @escaping (String) -> Void) {
    appSyncClient?.fetch(query: ListTodosQuery(), cachePolicy: .returnCacheDataAndFetch) {(result, error) in
        if error != nil {
            print(error?.localizedDescription ?? "")
            completionHandler("")
            return
        }
        print("Query complete.")
        var sampleString = ""
        result?.data?.listTodos?.items!.forEach {
            print(($0?.name)! + " " + ($0?.description)!)
            sampleString += $0?.name + " "
        }
        completionHandler(sampleString)
    }
}

func callQuery() {
    runQuery(completionHandler: { (result) in
        // do what you want
        print(result)
    })
}