iOS Photos Framework: how to revert image asset to original

Question

All the online document and samples showed how to edit/change assets with PHContentEditingInput and PHContentEditingOutput. I didn't find anything about resetting or reverting an image to its original. Anything wrote to renderedContentURL is considered an edit, so that's not what I want. Just share my findings here:

Answer 1

Use revertAssetContentToOriginal

Swift:

    PHPhotoLibrary.shared().performChanges({
        let request = PHAssetChangeRequest(for:asset)
        request.revertAssetContentToOriginal()
    }, completionHandler: { success, error in
        if !success { print("can't revert asset: \(error)") }
    })

Objective C:

     [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
         PHAssetChangeRequest *change = [PHAssetChangeRequest changeRequestForAsset:asset];
         [change revertAssetContentToOriginal];
     } completionHandler:^(BOOL success, NSError *error) {
         NSLog(@"Finished adding asset. %@", (success ? @"Success" : error));
     }];