react-use-context-selector v1.0.2

react-use-context-selector

Context selector hook for React

Introduction

There is currently no native way in React to subscribe to a part of context using hooks. That means changing a small part of context, can result in re-rendering every single component that uses the context.

There also exists another package, use-context-selector, for the same purpose, but it does not allow you to use the conventional Consumer anymore, and it also does not have type declarations.

Usage

For a working demo, please take a look at this code sandbox

npm install --save react-use-context-selector

import { createContext } from 'react';
import {
  createSelectorProvider,
  useContextSelector
} from "react-use-context-selector";

const context = createContext({
  name: 'Mike',
  age: 25,
});
const ProviderWithSelector = createSelectorProvider(context);

// Root Component
function Root() {
  return (
    <ProviderWithSelector>
      <MyComponent />
    </ProviderWithSelector>
  );
}

// The component that consumes the context
function MyComponent() {
  // This component will re-render only if the name within the context object change.
  const name = useContextSelector(context, value => value.name);

  return <div>{name}</div>;
}