NSOperation Dependencies

[subdigital]

Written on 08/03/2017 13:55:08

URL: https://nsscreencast.com/episodes/177-nsoperation-dependencies

[subdigital]

originally written by liuyao on 07/16/2015 23:55:12

what do you mean slog is not thread safe ? would you talk something about thread safe?

[subdigital]

originally written by liuyao on 07/20/2015 05:25:51

nslog

[subdigital]

originally written by Derek on 10/14/2015 09:39:52

In your code, you put filterOperation inside the completion block of filterOperation. Wouldn't it be a retain cycle?

[subdigital]

originally written by Derek on 10/14/2015 12:13:03

In your code, you put filterOperation inside the completion block of filterOperation. Wouldn't it be a retain cycle?

[subdigital]

originally written by subdigital on 10/14/2015 12:49:31

Good catch. Because the operation’s completion block only gets released in the operation’s dealloc, this would be a retain cycle. That one should be weakly referenced inside the block.

[subdigital]

originally written by Mohammed M. Ennabah on 10/13/2017 19:54:31

Why didn't you use the main() in ResizeOperation to resize the image as long you don't have a completionHandler? instead, you used execute() with finish().

[subdigital]

originally written by subdigital on 10/13/2017 19:59:08

For consistency. The base class _requires_ you to use `execute()` (see https://github.com/nsscreen.... Doing it this way means all operations are treated the same way. For asynchronous ones, it fits naturally, and for synchronous ones they use the same API, but just inline.

[subdigital]

originally written by Mohammed M. Ennabah on 10/13/2017 20:26:11

gotcha, fatalError("You must override this") because I'm using the subclassed Operation. Thanks

[subdigital]

originally written by Mohammed M. Ennabah on 10/13/2017 20:58:16

Thanks for clarification 👍