Wait until multiple networking requests have all executed - including their completion blocks

Question

I have multiple operations (they\'re AFNetworking requests) with completion blocks that takes some time to execute, and a Core Data object that needs to be saved at the end

Answer 1

My requirements were those of do many request from an array of String (URL)

func updateSourceData(element: Int) {

    if element > availableUrls.count - 1 {
        return
    }

    let service = SourceDataServiceDao()
    let currentUrl = availableUrls[element]
    service.fooCall(url: currentUrl, completion: { (response, error) -> Void in
        self.updateSourceData(element + 1)
    })

}

Obviously, in this way calls are made in cascade, not N asynchronous calls.