Hands-On Design Patterns with Swift

Using the proxy pattern to implement request/response logging

The proxy pattern is very useful when you need to forward all calls from one object to another. In our case, we could have implemented CachedNetworking as a proxy on URLSession, effectively giving additional caching capabilities to URLSession.

When debugging your applications, it may be useful to log information about networking calls, such as duration, whether they come from the cache, and so on.

The proxy pattern and the decorator pattern are actually quite similar at first glance. They both attempt to solve similar problems in a similar way. However, the proxy pattern is applied at compile time, while the decorator pattern is only applied at runtime, as discussed earlier.