This is a simple registry class to codify all the core features used by the asset system. Features listed in here are provided in some capacity by the core. Fundamental features like pages, files and users aren't used by the block feature system, because it's assumed the core will always have these available. However, they may be used in the future with a fully modular installation procedure.


Denotes that a particular block controller uses features, and allows the block controller to specify which features it requires to function. This allows blocks like the calendar, for example, to specify that they require the Calendar feature to function, which lets them use the feature fallback if the current theme doesn't support those features.