* Firebase API for messaging

packages/firebase/README.md

@@ -0,0 +1,26 @@
+# Firebase support
+
+## Pascal API
+This directory contains the firebase messaging support files for Pas2JS.
+The src directory contains the firebaseapp unit which provides an interface
+for Firebase Cloud messaging APIs from Google.
+
+##  Support files
+The js directory contains the support files needed to make it work. 
+The Google API compatibility API is used, the version saved in the js
+directory is known to work.
+
+You must use these files in your main HTML file:
+```html
+  <script src="firebase-app-compat.js"></script>
+  <script src="firebase-messaging-compat.js"></script>
+```
+
+The firebase-messaging-sw.js file is a small service worker file that you can register
+with the following call :
+```javascript
+Window.Navigator.serviceWorker.register('firebase-messaging-sw.js')
+```
+
+A demo application can be found in FPC fcl-web/examples/fcm/webclient
+

packages/firebase/js/firebase-messaging-sw.js

@@ -0,0 +1,21 @@
+importScripts('https://www.gstatic.com/firebasejs/9.2.0/firebase-app-compat.js');
+importScripts('https://www.gstatic.com/firebasejs/9.2.0/firebase-messaging-compat.js');
+importScripts('config.js');
+
+firebase.initializeApp(firebaseConfig);
+
+const messaging = firebase.messaging();
+
+// If you would like to customize notifications that are received in the
+// background (Web app is closed or not in browser focus) then you should
+// implement this optional method.
+// Keep in mind that FCM will still show notification messages automatically 
+// and you should use data messages for custom notifications.
+// For more info see: 
+// https://firebase.google.com/docs/cloud-messaging/concept-options
+messaging.onBackgroundMessage(function(payload) {
+  console.log('[firebase-messaging-sw.js] Received background message ', payload);
+  // Customize notification here
+  const notificationTitle = 'We received a message';
+  self.registration.showNotification(notificationTitle,payload.notification);
+});

packages/firebase/namespaced/Api.Firebase.pas

@@ -0,0 +1,3 @@
+{$DEFINE FPC_DOTTEDUNITS}
+unit Api.Firebase;
+{$include ../src/firebaseapp.pp}

packages/firebase/src/firebaseapp.pp

@@ -0,0 +1,62 @@
+unit firebaseapp;
+{
+  Minimal interface for firebird messaging using compatibility API.
+}
+
+{$mode ObjFPC}
+{$modeswitch externalclass}
+
+interface
+
+uses js, types, weborworker, web;
+
+Type
+
+  TMessagingGetTokenOptions = class external name 'Object' (TJSObject)
+    serviceWorkerRegistration : TJSServiceWorkerRegistration;
+    vapidKey : string;
+  end;
+
+  TFirebaseUnsubscribeFunction = reference to procedure;
+
+  TFirebaseMessageCallBack = reference to procedure(aMessage : TJSObject);
+
+  TFirebaseMessaging = class external name 'firebase.messaging.Messaging' (TJSObject)
+    function deleteToken : boolean; async;
+    function getToken : string; async;
+    function getToken (options : TMessagingGetTokenOptions): string; async;
+    function onBackgroundMessage(aCallback : TFirebaseMessageCallBack) : TFirebaseUnsubscribeFunction;
+    function onMessage(aCallback : TFirebaseMessageCallBack) : TFirebaseUnsubscribeFunction;
+    procedure useServiceWorker(registration : TJSServiceWorkerRegistration);
+  end;
+
+  TFirebaseApp = class external name 'firebase.app.App' (TJSObject)
+  Private
+    fname : string; external name 'name';
+    FOptions : TJSObject; external name 'options';
+  Public
+    function messaging : TFirebaseMessaging;
+    property name: string read FName;
+    property options : TJSObject read FOptions;
+  end;
+
+  TFirebaseLogCallBack = procedure (args : TJSValueDynArray; level : string; Message : string; _type : string);
+
+  TFirebase = class external name 'Firebase' (TJSObject)
+  Private
+    fapps : TJSObjectDynArray; external name 'apps';
+  Public
+    function initializeApp(Obj : TJSObject) : TFirebaseApp;
+    function initializeApp(Obj : TJSObject; const aName : string) : TFirebaseApp;
+    procedure onLog(callback : TFirebaseLogCallBack);
+    procedure onLog(callback : TFirebaseLogCallBack; options : TJSObject);
+    property apps : TJSObjectDynArray read fapps;
+  end;
+
+var
+  firebase : TFirebase external name 'firebase';
+
+implementation
+
+end.
+