RXSwift - Waiting multiple API or task to finish

Question

I am new to RxSwift and I would like to achieve something like this. Here's the situation

I have 2 different APIs that needs to populate in a UITableView. Therefore I need to combine 2 sets of data

I would like to achieve something like waiting 2 APIs finish returning the data only then I reload the UITableView once.

I've tried Observable.zip and Observable.combineLatest, but I still cannot get what I want.

Any one can help me on this?

Edited Here's the idea of how I want it to be done

func viewDidLoad() {
    setupObs()
    getBalance()
    getTransaction()
}

func getBalance() {
    //Call get balance
}

func getTransaction() {
    // Call get transaction
}

func setupObs() {
        Observable.zip(
            getBalance(),
            getTransaction()
        )
        .subscribe(onNext: { bal, trx in
            print("Done")
        }, onCompleted: {
            print("completed")
        }).disposed(by: disposeBag)

}

The output "Done" is being printed twice

Answer 1

The Observable.zip operator is exactly the right one to use. Likely though you are doing something else wrong. Your code should look like this:

Observable.zip(firstAPI(), secondAPI()) { firstResult, secondResult in
    combineData(first: firstResult, second: secondResult) // this must return an array!
}
.bind(to: tableView.rx.items) { tableView, row, item in
    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: IndexPath(row: row, section: 0))
    // configure cell with item
    return cell
}
.disposed(by: disposeBag)

Likely, your mistake is that you aren't returning an array from the operator and so the rx.items binder is complaining.