All good things come in threes, so I’m writing another post about how to access cookie or sessions. I got inspired by a comment from Chris Marisic, who suggested to use a more testable way for this stuff!
Previous posts about this topic:
Intro
Using static wrapper properties is a quick and easy way, but you can’t unit test them because they access HttpContext.Current directly. This time I will show you, how you can build a fully unit testable and strongly typed way to access your cookies. As there has been Christmas time 2 days ago (ASP.Net MVC RC1 was released *g*) I’m using the latest MVC bits for my example!
A Reusable Cookie Container
The cookie container is responsible for getting values out of and into the cookie collections. It does not know which concrete values I’m using in my application! This is implemented in a different level, so you can use this class for all of your applications!
In my implementation it’s possible to store “objects” in cookies. I’ve implemented it this way because I don’t want to convert all my DateTime, int, … cookies every time! But I also don’t want someone to save Lists or any other complex types, so my SetValue() method validates the type of the value and throws an exception, if it’s not a value type or nullable value type. That’s a little type checking, but I think it is worth it because cookies are set quite rarely!
