FBSessionTokenCachingStrategy is designed to be instantiated directly or used as a base class. Usually default token caching behavior is sufficient, and you do not need to interface directly with FBSessionTokenCachingStrategy objects. However, if you need to control where or how FBSession information is cached, then you may take one of two approaches.

The first and simplest approach is to instantiate an instance of FBSessionTokenCachingStrategy, and then pass the instance to FBSession class' init method. This enables your application to control the key name used in NSUserDefaults to store session information. You may consider this approach if you plan to cache session information for multiple users.

The second and more advanced approached is to derive a custom class from FBSessionTokenCachingStrategy, which will be responsible for caching behavior of your application. This approach is useful if you need to change where the information is cached, for example if you prefer to use the filesystem or make a network connection to fetch and persist cached tokens. Inheritors should override the cacheTokenInformation, fetchTokenInformation, and clearToken methods. Doing this enables your application to implement any token caching scheme, including no caching at all.

Direct use of FBSessionTokenCachingStrategyis an advanced technique. Most applications use FBSession objects without passing an FBSessionTokenCachingStrategy, which yields default caching to NSUserDefaults.