Wait for all Operations in queue to finish before performing task

Question

I have an Operation subclass and Operation queue with maxConcurrentOperationCount = 1.

This performs my operations in a sequential order that i add them which is goo

Answer 1

Code at the end of the queue refer to this link

NSOperation and NSOperationQueue are great and useful Foundation framework tools for asynchronous tasks. One thing puzzled me though: How can I run code after all my queue operations finish? The simple answer is: use dependencies between operations in the queue (unique feature of NSOperation). It's just 5 lines of code solution.

NSOperation dependency trick with Swift it is just easy to implement as this:

extension Array where Element: NSOperation {
/// Execute block after all operations from the array.
func onFinish(block: () -> Void) {
    let doneOperation = NSBlockOperation(block: block)
    self.forEach { [unowned doneOperation] in doneOperation.addDependency($0) }
    NSOperationQueue().addOperation(doneOperation)
}}