Page Visibility shim for jQuery

This plugin gives you a very simple API that allows you to execute callbacks when the page’s visibility state changes.

It does so by using the Page Visibility API where it’s supported, and falling back to good old focus and blur in older browsers.

Demo

http://mathiasbynens.be/demo/jquery-visibility

When to use?

Example use cases include but are not limited to pausing/resuming slideshows, video, and/or embedded audio clips.

Example usage

This plugin simply provides two custom events for you to use: show and hide. When the page visibility state changes, the appropriate event will be triggered.

You can use them separately:

$(document).on('show', function() {
  // the page gained visibility
});

$(document).on('hide', function() {
  // the page was hidden
});

Since most of the time you’ll need both events, your best option is to use an events map. This way, you can bind both event handlers in one go:

$(document).on({
  'show': function() {
    console.log('The page gained visibility; the `show` event was triggered.');
  },
  'hide': function() {
    console.log('The page lost visibility; the `hide` event was triggered.');
  }
});

The plugin will detect if the Page Visibility API is natively supported in the browser or not, and expose this information as a boolean (true/false) in $.support.pageVisibility:

if ($.support.pageVisibility) {
  // Page Visibility is natively supported in this browser
}

Notes

Both events live under the visibility namespace — so if you ever need to remove all event handlers added by this plugin, you could just use $(document).off('.visibility'); (or $(document).unbind('.visibility'); in jQuery 1.6 or older).

This plugin is not a Page Visibility polyfill, as it doesn’t aim to mimic the standard API. It merely provides a simple way to use this functionality (or a fallback) in your jQuery code.

License

This plugin is available under the MIT license.

Author

Mathias Bynens

Contributors

John-David Dalton