How Recoil Updates Only Subscribed Components
To use
Recoil, you first need to wrap your app with RecoilRoot. While it uses Context API internally to pass down state, it doesn't trigger full re-renders like regular React Context APIThis is because the store being passed down isn't a regular
React state, so changes to this context don't cause re-renders of components it passes through
So how do components using a
Recoil atom re-render when that atom's value changes through setState?Looking at
useRecoilValue, we can see it uses useStoreRef to get a reference to the Recoil store and uses the useRecoilValueLoadable hook to get a LoadableIt then uses
useState to create a setState function named forceUpdate, which is set as a callback function for subscribeToRecoilValueComponents using
useRecoilValue subscribe to changes in their recoilValue through the subscribeToRecoilValue function. When the Recoil runtime triggers the registered callback, the component's useState updates, causing only that specific component to re-renderData is declared in atom units, and state management becomes simpler using useRecoilState, which works very similarly to React's useState hook
