Ahmed AbdelHalim

Exceptions are as old as programming itself. An unhandled exception may cause unexpected behavior, and results can be spectacular. Over time, these errors have contributed to the impression that exceptions are bad. But exceptions are a fundamental element of modern programming. Rather than fearing exceptions, we should embrace them and learn how to benefit from them. In this article, we will discuss how to manage exceptions elegantly, and use them to write clean code that is more maintainable.

The publish-subscribe pattern] (or pub/sub, for short) is a messaging pattern where senders of messages (publishers), do not program the messages to be sent directly to specific receivers (subscribers). Instead, the programmer "publishes" messages (events), without any knowledge of any subscribers there may be. This article provides insight in how to use the pub/sub pattern, in Rails, to communicate messages between different system components without these components knowing anything about each other's identity.