how to apply Full screen striction in react js?

Question

Here i am developing an examination system. I want to apply full screen when i launch exam component. While doing student strict to remain in full screen. When he/she exit from full screen then automatically call a function to save exam result.

Answer 1

There are some limitations when it comes to displaying things fullscreen but I suggest you to use https://github.com/sindresorhus/screenfull.js . It's quite well maintained and makes it easier for you to support multiple browsers.

In React you could do something like this:

// import/exports depend on your setup, this is just an example
const screenfull = require('screenfull');

class MyComponent extends React.Component {
  componentDidMount() {
    if (screenfull.isEnabled) {
      screenfull.on('change', () => {
        console.log('Am I fullscreen?', screenfull.isFullscreen ? 'Yes' : 'No');
      });
    }
  }

  // enabling fullscreen has to be done after some user input
  toggleFullScreen = () => {
    if (screenfull.isEnabled) {
      screenfull.toggle();
    }
  }

  render() {
    return (
      <button onClick={this.toggleFullScreen}>Toggle fullscreen</button>
    )
  }
}

LE:

To detect a fullscreen change you can use the screenfull.on('change') event: https://github.com/sindresorhus/screenfull.js#detect-fullscreen-change

Added code for this in the above example.