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Introducing the React Freeze Library

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The Gray Cat

The React Freeze library is designed to help you prevent React component subtrees from rendering. This is particularly useful in scenarios where you want to avoid unnecessary re-renders of parts of your application that are not visible to the user at a given moment. By using this library, you can suspend renders for hidden components, thereby saving React from performing unnecessary computations.

Installation

To get started, you need to install the react-freeze package using npm or yarn:

yarn add react-freeze

Basic Usage

Here is a simple example of how to use the Freeze component to freeze a subtree of components:

import { Freeze } from "react-freeze";

function MyComponent({ shouldSuspendRendering }) {
  return (
    <Freeze freeze={shouldSuspendRendering}>
      <MyOtherComponent />
    </Freeze>
  );
}

In this example, the Freeze component is used to control whether the components under it should re-render. The freeze option can be set to true to suspend renders.

Advanced Usage

For more complex scenarios, you can use the Freeze component with additional options. Here is an example:

import { Freeze } from "react-freeze";

function MyComponent({ shouldSuspendRendering }) {
  return (
    <Freeze freeze={shouldSuspendRendering} placeholder={<div>Freezing...</div>}>
      <MyOtherComponent />
    </Freeze>
  );
}

In this example, the placeholder option is used to customize what the Freeze component should render when it is in the frozen state. This can be useful if you want to show a placeholder view instead of just rendering null.

Conclusion

The React Freeze library is a powerful tool for optimizing your React applications. By using it, you can avoid unnecessary re-renders and improve the performance of your application. Whether you are working on a React Native app or a traditional React application, this library can help you achieve better performance and a smoother user experience.

Known Issues

  • React Native Debugger does not allow profiling: When profiling React-Native apps with React Native Debugger, starting the React profiler for the app with frozen components throws an error.

FAQ

  • What happens to state changes that are executed on a frozen subtree?: All state changes are executed as usual, but they won’t trigger a render of the updated component until the component comes back from the frozen state.
  • What happens to the non-react state of the component after defrosting?: The state, such as scroll position or input state, is restored when the component comes back from the frozen state.
  • What happens when there is an update in a Redux store that a frozen component is subscribed to?: Redux and other state-management solutions will still run methods such as mapStateToProps or useSelector on store updates, but the component will not re-render until it comes back from the frozen state.

By following these best practices and using the React Freeze library, you can optimize your React applications for better performance and a smoother user experience.

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