Swift 3: Transfer Utility enumerateToAssignBlocks

Question

AWS white papers contain the following objective-c code

AWSS3TransferUtility *transferUtility = [AWSS3TransferUtility defaultS3TransferUtility]; [transferUtility enumerateToAssignBlocksForUploadTask:^(AWSS3TransferUtilityUploadTask *uploadTask, __autoreleasing AWSS3TransferUtilityUploadProgressBlock *uploadProgressBlockReference, __autoreleasing AWSS3TransferUtilityUploadCompletionHandlerBlock *completionHandlerReference) { NSLog(@"%lu", (unsigned long)uploadTask.taskIdentifier); // Use `uploadTask.taskIdentifier` to determine what blocks to assign. *uploadProgressBlockReference = // Reassign your progress feedback block. *completionHandlerReference = // Reassign your completion handler. } downloadTask:^(AWSS3TransferUtilityDownloadTask *downloadTask, __autoreleasing AWSS3TransferUtilityDownloadProgressBlock *downloadProgressBlockReference, __autoreleasing AWSS3TransferUtilityDownloadCompletionHandlerBlock *completionHandlerReference) { NSLog(@"%lu", (unsigned long)downloadTask.taskIdentifier); // Use `downloadTask.taskIdentifier` to determine what blocks to assign. *downloadProgressBlockReference = // Reassign your progress feedback block. *completionHandlerReference = // Reassign your completion handler. }]; 

I tried converting it to Swift 3 (download only)

 transferUtility.enumerateToAssignBlocks(forUploadTask: { let progressPointer = AutoreleasingUnsafeMutablePointer<AWSS3TransferUtilityUploadProgressBlock?>(&uploadProgressBlock) let completionPointer = AutoreleasingUnsafeMutablePointer<AWSS3TransferUtilityUploadCompletionHandlerBlock?>(&completionBlock) progress = progressPointer completion = completionPointer } , downloadTask: nil) 

But Xcode throws the following error

It is not possible to convert a value of type () → () into the expected type of the argument [...]

Has anyone gotten a job in Swift 3? Probably the method signatures have changed

EDIT:

I applied @donkon's answer:

  transferUtility.enumerateToAssignBlocks(forUploadTask: { (uploadTask:AWSS3TransferUtilityUploadTask, progress:AutoreleasingUnsafeMutablePointer<(@convention(block) (AWSS3TransferUtilityTask, Progress) -> Void)?>?, error: AutoreleasingUnsafeMutablePointer<(@convention(block) (AWSS3TransferUtilityUploadTask, Error?) -> Void)?>?) in let progressPointer = AutoreleasingUnsafeMutablePointer<AWSS3TransferUtilityProgressBlock?>(&self.progressBlock) let completionPointer = AutoreleasingUnsafeMutablePointer<AWSS3TransferUtilityUploadCompletionHandlerBlock?>(&self.completionHandler) // progress = progressPointer completion = completionPointer }, downloadTask: nil) 

Xcode now reports that both progress and completion are valid values ​​and cannot be changed.

Answer 1

The method you are trying to use has arguments that are functions. These functions in the SDK are written in Objective-C. Therefore, you should use @convention(block) to indicate that they are Objective-C compatible block references.

 AWSS3TransferUtility.default().enumerateToAssignBlocks(forUploadTask: { (uploadTask:AWSS3TransferUtilityUploadTask, uploadProgressBlockReference:AutoreleasingUnsafeMutablePointer<(@convention(block) (AWSS3TransferUtilityTask, Progress) -> Void)?>?, completionHandlerReference: AutoreleasingUnsafeMutablePointer<(@convention(block) (AWSS3TransferUtilityUploadTask, Error?) -> Void)?>?) in print("Hello, world") uploadProgressBlockReference?.pointee = {(task:AWSS3TransferUtilityTask, progress:Progress) -> Void in print("Fraction completed: \(progress.fractionCompleted)") } }, downloadTask: nil)