Have you ever been working on a project that has session variables controlling important aspects of functionality? When they start falling out of controllers and views into a big pile of soup on the floor it’s probably time to encapsulate them.
Although relying on the session object in controllers and views is relatively easy to understand, you should be very wary when you’re tempted to use them this way. Thinking, “I’ll just add a session variable for this” will probably lead to misunderstandings or bugs later on. And on…
Boards of Canada wrote a song called Constants are Changing. In Ruby even constants are dynamic, holding a reference to an object rather than the object itself. This consistency makes modifying constants possible, and rather than being something considered distasteful it may form an integral part of the design of a system.
Changing a constant’s reference will result in a warning, but there are times when ignoring these warnings might be arguably legitimate. I wrote a simple tool that runs for long periods of time, and …
