Proxy(Chapter 22 of Pro Objective-C Design Patterns for iOS)

You’d naturally think about using the pattern when 􀀁 You need a remote proxy that provides a local representative for an object in a different address space or in the network. 􀀁 You need a virtual proxy to create heavy-weighted objects on demand. We will implement that kind of proxy in a code example later in this chapter. 􀀁 You need a protection proxy to control access to the original object based on different access rights. 􀀁 You need a smart-reference proxy for counting the number of references to the real object for memory management. It can also be used for locking the real object so no other objects can change it.