Lazy loading is a design pattern widely used software industry to defer tasks of object until the point at which it is needed. It not only efficiency in program's operation but also improved the user experience.
This demo is about table view image lazy loading implemented by Operations, inspired by Apple's LazyTableImages and raywenderlich's operationqueue-tutorial
Operation is a high level API based on GCD that has some advance features like cancel, suspend, and resume.
Operation only can perform once and cannot be execute again.
We usually put operations into operationqueu but you can manually trigger operation by calling its start() method and you will take care the readiness state.
An OperationQueue executes its queued operations.
Author: Wayne Hsiao