Copying AFHTTPRequestOperation results in error "request body stream exhausted" - ios

Question

Problem
My app lets users upload photos. This works great.
Now, I am trying to implement a "retry" function if the photo upload fails, for example due to a slow connection.
Here's my retry code:
self.operation = [self.operation copy]; // Creates a new operation with the same NSURLRequest
[self.operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
// do success stuff
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog("%#", error);
}];
[[MyAFHTTPClient sharedClient] enqueueHTTPRequestOperation:self.operation];
Upon starting, the failure block is called, outputting:
$0 = 0x12636b50 Error Domain=NSURLErrorDomain Code=-1021 "request body stream exhausted" UserInfo=0x12637810 {NSErrorFailingURLStringKey=https://my/long/url/, NSErrorFailingURLKey=https://my/long/url/, NSLocalizedDescription=request body stream exhausted, NSUnderlyingError=0x13046bb0 "request body stream exhausted"}
Question
How do I change my code to restart the image upload correctly?
What I've tried
I think the issue is that operation.request.HTTPBodyStream is an NSInputStream, which cannot be restarted.
The method -[AFURLConnectionOperation connection:needNewBodyStream:] appears to provide a copy of the input stream. I set a breakpoint in there; it's not called when copying or starting the operation, and I'm not sure how to trigger it.
There's some discussion on a similar issue on the AFNetworking GitHub page, but that relates to retrying after authentication failure.
Other info
My URL Request object is created using -[AFHTTPClient multipartFormRequestWithMethod:
path:
parameters:
constructingBodyWithBlock:]

Answer 1

I would try something like this :
-(void)uploadImage:(NSData *)imageData retry:(BOOL)retry
{
AFHTTPClient *myClient = [[AFHTTPClient alloc] initWithBaseUrl:myBaseURL];
NSURLRequest *request = [myClient multipartFormRequestWithMethod:#"POST"
path:myPath
parameters:myParametersDictionary
constructingBodyWithBlock:^(id <AFMultipartFormData> formData){
[formData appendPartWithFileData:imageData
name:myImageName
fileName:myFileName
mimeType:#"image/jpg"];
}];
AFHTTPRequestOperation *operation = [myClient HTTPRequestOperationWithRequest:request
success:^(AFHTTPRequestOperation *operation, id responseObject) {
// do success stuff
}
failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog("%#", error);
if (retry) {
[self uploadImage:imageData
retry:NO];
}
}];
[myClient enqueueHTTPRequestOperation:operation];
}
Of course the first time you would call it with retry:YES