<!DOCTYPE html>
<html lang="en">
 
<head>
   
<meta charset="utf-8" />
   
<meta name="viewport" content="width=device-width, initial-scale=1" />
   
<meta name="color-scheme" content="dark light" />
   
<link rel="manifest" href="manifest.json" />
   
<title>How to add Richer Install UI to your web app</title>
   
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      if ('serviceWorker' in navigator) {
        window.addEventListener('load', () => {
          navigator.serviceWorker.register('sw.js');
        });
      }
    </script>
    <script type="module" src="script.js"></script> -->

 
</head>
 
<body>
   
<h1>How to add Richer Install UI to your web app</h1>
   
<ol>
     
<li>
        Install the app by clicking the button below. After the installation,
        the button is disabled.
       
<p>
         
<button disabled type="button">Install</button>
       
</p>
     
</li>
     
<li>
        When you click on install a dialog similar to the ones from app stores
        will be displayed.
     
</li>
     
<li>
        The dialog includes the `description` and `screenshots` set in the app
        manifest.
     
</li>
     
<li>
        Screenshots should be different depending if the app is being installed
        on a mobile or desktop device, according to the `form_factor` value set
        for the screenshots on the manifest
     
</li>
   
</ol>
 
</body>
</html>

       
// The install button.
const installButton = document.querySelector('button');

// Only relevant for browsers that support installation.
if ('BeforeInstallPromptEvent' in window) {
 
// Variable to stash the `BeforeInstallPromptEvent`.
  let installEvent
= null;

 
// Function that will be run when the app is installed.
 
const onInstall = () => {
   
// Disable the install button.
    installButton
.disabled = true;
   
// No longer needed.
    installEvent
= null;
 
};

  window
.addEventListener('beforeinstallprompt', (event) => {
   
// Do not show the install prompt quite yet.
    event
.preventDefault();
   
// Stash the `BeforeInstallPromptEvent` for later.
    installEvent
= event;
   
// Enable the install button.
    installButton
.disabled = false;
 
});

  installButton
.addEventListener('click', async () => {
   
// If there is no stashed `BeforeInstallPromptEvent`, return.
   
if (!installEvent) {
     
return;
   
}
   
// Use the stashed `BeforeInstallPromptEvent` to prompt the user.
    installEvent
.prompt();
   
const result = await installEvent.userChoice;
   
// If the user installs the app, run `onInstall()`.
   
if (result.outcome === 'accepted') {
      onInstall
();
   
}
 
});

 
// The user can decide to ignore the install button
 
// and just use the browser prompt directly. In this case
 
// likewise run `onInstall()`.
  window
.addEventListener('appinstalled', () => {
    onInstall
();
 
});
}