This code snippet is used to detect when a user navigates away from a web page In Vue.

It’s useful when you want to pause animations, videos, or any other activities that shouldn’t continue when the user isn’t actively viewing the page.

Table of Contents

Code Snippet:

<script>
export default {
  mounted () {
    document.addEventListener('visibilitychange', this.handleVisibility, false)
  },
  methods: {
    handleVisibility () {
      if (document.visibilityState === 'hidden') {
        // pause animation, video, etc
      } else {
        // continue operation
      }
    }
  }
};
</script>

Explanation:

The code listens for the 'visibilitychange' event, which is fired when a user navigates away from or back to a web page. When this event fires, the ‘handleVisibility’ method is called.

This method checks the 'visibilityState' property of the document. If it’s ‘hidden’, the user has navigated away from the page, and any necessary actions (like pausing an animation) can be taken.

If it’s not ‘hidden’, the user has navigated back to the page, and any necessary resumption of operations can occur.

Usage:

To use this code snippet, you’ll need to have a Vue project set up.

You can add this code to any Vue component where you want to detect the visibility change.

Also, remember to replace the comments in the 'handleVisibility' method with the code to pause and resume operations as needed.

Example:

Let’s say you have a video playing on your webpage, and you want to pause it when the user navigates away. Your ‘handleVisibility’ method might look like this:

handleVisibility () {
  if (document.visibilityState === 'hidden') {
    this.pauseVideo();
  } else {
    this.resumeVideo();
  }
}

Here, 'pauseVideo' and 'resumeVideo' would be additional methods you’ve defined on the Vue component to pause and resume the video, respectively.

Conclusion

This is a simple but effective way to detect when a user navigates away from a web page in Vue.

It’s particularly useful when you have operations that should only continue when the user is actively viewing the page.

Remember to replace the comments in the ‘handleVisibility’ method with the actual code for pausing and resuming your specific operations.

Further Reading