I am using AFNetworking to download files that my app uses for a sync solution. At certain times, the app downloads a series of files as a batch unit. Following this example, I run the batch like this:
NSURL *baseURL = <NSURL with the base of my server>;
AFHTTPRequestOperationManager *manager = [[AFHTTPRequestOperationManager alloc] initWithBaseURL:baseURL];
// as per: https://stackoverflow.com/a/19883392/353137
dispatch_group_t group = dispatch_group_create();
for (NSDictionary *changeSet in changeSets) {
dispatch_group_enter(group);
AFHTTPRequestOperation *operation =
[manager
POST:@"download"
parameters: <my download parameters>
success:^(AFHTTPRequestOperation *operation, id responseObject) {
// handle download success...
// ...
dispatch_group_leave(group);
}
failure:^(AFHTTPRequestOperation *operation, NSError *error) {
// handle failure...
// ...
dispatch_group_leave(group);
}];
[operation start];
}
// Here we wait for all the requests to finish
dispatch_group_notify(group, dispatch_get_main_queue(), ^{
// run code when all files are downloaded
});
This works well for the batch downloads. However, I want to display to the user an MBProgressHUD which shows them how the downloads are coming along.
AFNetworking provides a callback method
[operation setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
}];
... which lets you update a progress meter pretty easily, simply by setting the progress to totalBytesRead / totalBytesExpectedToRead
. But when you have multiple downloads going simultaneously that is hard to keep track of on a total basis.
I have considered having an NSMutableDictionary
with a key for each HTTP operation, with this general format:
NSMutableArray *downloadProgress = [NSMutableArray arrayWithArray:@{
@"DownloadID1" : @{ @"totalBytesRead" : @0, @"totalBytesExpected" : @100000},
@"DownloadID2" : @{ @"totalBytesRead" : @0, @"totalBytesExpected" : @200000}
}];
As each operation's download progresses, I can update the totalBytesRead
for that specific operation in the central NSMutableDictionary
-- and then total up all the totalBytesRead
and totalBytesExpected' to come up with the total for the whole batched operation. However, AFNetworking's progress callback method
downloadProgressBlock, defined as
^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead){}does not include the specific operation as a callback block variable (as opposed to the
successand
failure` callbacks, which do contain the specific operation as a variable, making it accessible). Which makes it impossible, as far as I can tell, to determine which operation specifically is making the callback.
Any suggestions on how to track the progress of multipole simultaneous downloads using AFNetworking?
when starting the operations, you could safe each operation, downloadID and the values for totalbytesRead and totalBytesExpected together in a NSDictionary and all dicts to your downloadProgressArray.
Then when the callback methods is invoked, loop through your array and compare the calling operation with the operation in each dict. this way you should be able to identify the operation.