app files restructure

Frontend/web/install_pwa.js

@@ -0,0 +1,33 @@
+let deferredPrompt;
+
+// add to homescreen
+window.addEventListener("beforeinstallprompt", (e) => {
+    // Prevent Chrome 67 and earlier from automatically showing the prompt
+    e.preventDefault();
+    // Stash the event so it can be triggered later.
+    deferredPrompt = e;
+});
+
+function isDeferredNotNull() {
+    return deferredPrompt != null;
+}
+
+function presentAddToHome() {
+    if (deferredPrompt != null) {
+        // Update UI to notify the user they can add to home screen
+        // Show the prompt
+        deferredPrompt.prompt();
+        // Wait for the user to respond to the prompt
+        deferredPrompt.userChoice.then((choiceResult) => {
+            if (choiceResult.outcome === "accepted") {
+                console.log("User accepted the A2HS prompt");
+            } else {
+                console.log("User dismissed the A2HS prompt");
+            }
+            deferredPrompt = null;
+        });
+    } else {
+        console.log("deferredPrompt is null");
+        return null;
+    }
+}