Self-taught Android, iOS (Swift) and Full Stack Web Developer.
Creating an operation can also be done in multiple ways. Either you can create an Operation with a block, or subclass. In case you subclass, don’t forget to call finish, otherwise, the operation will never stop.
MVC (Model-View-Controller) is Apple’s recommended architectural pattern. The definition could be found here. The interaction between objects in the MVC is depicted as the following figure: