Haven't you wished for try
to sometimes try a little harder? Meet retry
To run the example project, clone the repo, and run pod install
from the Example directory first.
The full test suite shows a variety of use cases.
NB: The sync retry
is not good for use on the main thread (because it will block it if you're having delays, etc). For the main thread it's better considering retryAsync
(more info below).
Default parameters - retry three times without any delay:
retry {
... do some throwing work ...
}
Catching the last error, and adding a defer block after all tries have finished - will keep trying maximum 10
times. You can use either of the final blocks or both:
retry (max: 10) {
... do some throwing work ...
}
.finalCatch {lastError in
print("This simply won't happen. Failed with: \(lastError)")
}
.finalDefer {
print("Finished trying")
}
Add 2
second delay between the retries:
retry (max: 5, retryStrategy: .delay(seconds: 2.0)) {
... do some throwing work ...
}
Implement any custom delay logic (below is multiplying the waiting time after each try):
retry (max: 5, retryStrategy: .custom {count, lastDelay in return (lastDelay ?? 1.0) * 2.0} ) {
... do some throwing work ...
}
Limit the number of retries based on any custom logic - if you return nil
from your custom strategy, retry
will stop trying:
retry (max: 5, retryStrategy: .custom {count,_ in return count > 3 ? nil : 0} ) {
... do some throwing work ...
}
The syntax for retryAsync
is exactly the same as for retry
. The difference in behavior is if the first try fails retryAsync
keeps trying asynchronously instead of blocking the current thread.
NB: Before official Cocoapod release for swift 3.0, you can't use Retry via pods
Retry is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod "Retry"
Marin Todorov, 2016-present Inspired by https://github.com/RxSwiftCommunity/RxSwiftExt
Retry is available under the MIT license. See the LICENSE file for more info.