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When you call setState on a component, only that component's subtree is reconciled and re-rendered.
by acdlite 10y ago
When you call setState on a component, only that component's subtree is reconciled and re-rendered.
- rukuu001 10y agoThat's in the virtual DOM. React will diff the VDOM and browser DOM and only render actual differences. The React API will also let a component decide for itself if it should be rendered.
- deleted 10y ago[deleted]
- amelius 10y agoOkay. But how do you know what components to call setState on then? Is state spread over components, or is it stored centrally?
- acdlite 10y agosetState is a public API, usually triggered in response to a user event like a click or an input change event. State in React is local to a component, but it can be passed down to a component's children in the form of props. Centralized state can be achieved using a library like Redux, where an individual component subscribes to an external data store's changes. Redux abstracts the details away, but under the hood it's still just setState.