Mobx incorporates functional reactive programming principles, and uses observables as its stores:
You can tag entities (for example, objects and arrays) as observables using the @observable decorator. You can also tag some functions with the @computed decorator to make it into a derivation or reaction. The @computed functions will be re-run each time the @observable store has changed.
Decorators are a proposed addition to ECMAScript, currently tracked at github.com/tc39/proposal-decorators.
A derivation is a value that can be derived solely from the state. For example, we can make our LoginPage component a derivation of the state. When ...