React.callback code example

Example 1: react bind function to component

class Foo extends Component {
  constructor(props) {
    super(props);
    this.handleClick = this.handleClick.bind(this);
  }
  handleClick() {
    console.log('Click happened');
  }
  render() {
    return <button onClick={this.handleClick}>Click Me</button>;
  }
}

Example 2: callback in react

import React, { useCallback } from 'react';

function MyComponent() {
  // handleClick is the same function object
  const handleClick = useCallback(() => {    console.log('Clicked!');  }, []);
  // ...
}

Example 3: react callback

import React, {useState} from 'react';

// Create a callback in the probs, in this case we call it 'callback'
function newCallback(callback) {
  callback('This can be any value you want to return')
}

const Callback = () => {

const [callbackData, setCallbackData] = useState('')

// Do something with callback (in this case, we display it on screen)
function actionAferCallback (callback) {
  setCallbackData(callback)
}

// Function that asks for a callback from the newCallback function, then parses the value to actionAferCallback
function requestCallback() {
  newCallback(actionAferCallback)
}

  return(
    <div>
      {/* A button to activate callback */}
      <button onClick={() => {requestCallback()}}>Request Callback</button>
      {callbackData}
    </div>
  )
}

export default Callback;