Table of Contents

1. Introduction
2. What is React Profiler?
3. Basics of React Profiler API
4. Detailed Explanation of the callback Function
5. Real-World Example
6. Conclusion

1. Introduction

React Profiler API is a powerful tool for analyzing the performance of React applications. Dive into its appeal in this article.

2. What is React Profiler?

React Profiler is a tool that analyzes the rendering information of components.

3. Basics of React Profiler API

By using the Profiler component, you can obtain the performance information of a component.

import React, { Profiler } from 'react';

function MyComponent() {
  return (
    <Profiler id="MyComponent" onRender={callback}>
      {/* Component content */}
    </Profiler>
  );
}

4. Detailed Explanation of the callback Function

The onRender callback receives detailed information about rendering.

function callback(
  id,
  phase,
  actualDuration,
  baseDuration,
  startTime,
  commitTime,
  interactions
) {
  // Handle profiling data here
}

• id: A unique ID for the profiled Profiler component. Used to identify it if multiple Profilers are used.
• phase: Either "mount" or "update", indicating the rendering phase of the component.
• actualDuration: The actual time (in milliseconds) taken to render the component and its descendants. Useful for identifying performance bottlenecks.
• baseDuration: The ideal rendering time (in milliseconds) if there were no unnecessary re-renders.
• startTime: The time when React started rendering. Useful for measuring rendering efficiency.
• commitTime: The time when React committed the changes to the DOM. Used to know when the browser drew the changes.
• interactions: The user interactions related to this rendering. Used to track how user actions affected the rendering.

5. Real-World Example

function callback(id, phase, actualDuration) {
  console.log(`Component ${id} took ${actualDuration} milliseconds in the ${phase} phase.`);
}

This way, you can output the time taken for a specific component's rendering to the log.

6. Conclusion

The React Profiler API is a robust tool for analyzing and optimizing the performance of your React app. Especially by using the callback function, specific analysis becomes possible.

Feel free to leave a like or comment!