docs(firebase-guide): update guide with Capacitor 2.0 changes (#2598)

site/docs-md/guides/push-notifications-firebase.md

@@ -21,7 +21,7 @@ Building and deploying iOS and Android applications using Capacitor requires a b
 
 To test push notifications on iOS, Apple requires that you have [a paid Apple Developer account](https://developer.apple.com/) and a *physical* iOS device.
 
-## Prepare an Ionic App
+## Prepare an Ionic Capacitor App
 If you have an existing Ionic 4 app, skip this section. If not, let's create an Ionic app first. 
 
 In your preferred terminal, install the latest version of the Ionic CLI:
@@ -30,27 +30,21 @@ In your preferred terminal, install the latest version of the Ionic CLI:
 npm install -g ionic
 ```
 
-Next, let's use the CLI to create a new Ionic 4 app based on the **blank** starter project and call it **capApp**:
+Next, let's use the CLI to create a new Ionic 4 Angular app based on the **blank** starter project and call it **capApp**:
 
 ```bash
-ionic start capApp blank
+ionic start capApp blank --type=angular
 ```
 
-## Add Capacitor
+On the prompt asking to integrate your new app with Capacitor, type `y` and press enter. That will add Capacitor and the Capacitor CLI to our new application.
 
 Once the application has been created successfully, switch to the newly created project directory:
 
 ```bash
 cd capApp/
 ```
 
-Next, let's add Capacitor and the Capacitor CLI to our new application...
-
-```bash
-ionic integrations enable capacitor
-```
-
-... and finish up by running `npx cap init`, which will allow us to fill out our app information.
+Finish up by running `npx cap init`, which will allow us to fill out our app information.
 
 ```bash
 npx cap init
@@ -59,7 +53,7 @@ npx cap init
 ```
 
 ## Building the App & Adding Platforms
-Before adding any native platforms to this project, the app must be built at least once. A web build creates the web assets directory that Capacitor needs (`www` folder in Ionic projects).
+Before adding any native platforms to this project, the app must be built at least once. A web build creates the web assets directory that Capacitor needs (`www` folder in Ionic Angular projects).
 
 ```bash
 ionic build
@@ -98,8 +92,17 @@ export class HomePage implements OnInit {
 ngOnInit() {
     console.log('Initializing HomePage');
 
-    // Register with Apple / Google to receive push via APNS/FCM
-    PushNotifications.register();
+    // Request permission to use push notifications
+    // iOS will prompt user and return if they granted permission or not
+    // Android will just grant without prompting
+    PushNotifications.requestPermission().then( result => {
+      if (result.granted) {
+        // Register with Apple / Google to receive push via APNS/FCM
+        PushNotifications.register();
+      } else {
+        // Show some error
+      }
+    });
 
     // On success, we should be able to receive notifications
     PushNotifications.addListener('registration', 
@@ -155,7 +158,17 @@ export class HomePage implements OnInit {
   ngOnInit() {
     console.log('Initializing HomePage');
 
-    PushNotifications.register();
+    // Request permission to use push notifications
+    // iOS will prompt user and return if they granted permission or not
+    // Android will just grant without prompting
+    PushNotifications.requestPermission().then( result => {
+      if (result.granted) {
+        // Register with Apple / Google to receive push via APNS/FCM
+        PushNotifications.register();
+      } else {
+        // Show some error
+      }
+    });
 
     PushNotifications.addListener('registration', 
       (token: PushNotificationToken) => {
@@ -180,6 +193,7 @@ export class HomePage implements OnInit {
         alert('Push action performed: ' + JSON.stringify(notification));
       }
     );
+  }
 }
 ```