React Native FCM Notification Builder Snippets

 //Creating notification builder
     notificationBuilder = () => {
         // Creating channel for android 8.0.0 (API 26)
        const channel = new firebase.notifications.Android.Channel(
            "channelId",
            "channelId",
            firebase.notifications.Android.Importance.Max
        ).setDescription("Channel Description");
        firebase.notifications().android.createChannel(channel);
        firebase.messaging().subscribeToTopic("channel_topic");

        // the listener returns a function you can use to unsubscribe
        this.unsubscribeFromNotificationListener = firebase
            .notifications()
            .onNotification(notification => {
                // for Android Notification
                if (Platform.OS === "android") {
                    const localNotification = new firebase.notifications.Notification(
                        {
                            sound: "default",
                            show_in_foreground: true,
                        }
                    )
                        .setNotificationId(notification.notificationId)
                        .setTitle(notification.title)
                        .setSubtitle(notification.subtitle)
                        .setBody(notification.body)
                        .setData(notification.data)
                        .android.setChannelId("channelId") // e.g. the id you chose above
                        .android.setSmallIcon("ic_stat_ic_notification") // set icon (must be samee with manifest)
                        .android.setColor("#2196F3") // you can set a color here (hexcode must be same with manifest)
                        .android.setAutoCancel(true)
                        .android.setBigText(notification.body)
                        .android.setPriority(
                            firebase.notifications.Android.Priority.Default
                        );

                    //handle notification action if application is on foreground / background
                    firebase
                        .notifications()
                        .onNotificationOpened(this.onNotificationPressed);

                    // Displaying notification
                    firebase
                        .notifications()
                        .displayNotification(localNotification)
                        .catch(error =>
                            console.error(
                                "Home.js : " +
                                    "firebase.notifications Android error : " +
                                    error
                            )
                        );
                } else if (Platform.OS === "ios") {
                    const localNotification = new firebase.notifications.Notification()
                        .setNotificationId(notification.notificationId)
                        .setTitle(notification.title)
                        .setSubtitle(notification.subtitle)
                        .setBody(notification.body)
                        .setData(notification.data)
                        .ios.setBadge(notification.ios.badge);

                    firebase
                        .notifications()
                        .onNotificationOpened(this.onNotificationPressed);
                    firebase
                        .notifications()
                        .displayNotification(localNotification)
                        .catch(error =>
                            console.error(
                                "Home.js : " +
                                    "firebase.notifications IOS error : " +
                                    error
                            )
                        );
                }
            });
        this.handleInitialNotification();
    };

     //Handling initialNotification (opened notification when apps closed)
     async handleInitialNotification() {
        const oldNotification = await AsyncStorage.getItem("notification");
        console.log("Home.js : " + "oldNotifID -> " + oldNotification);

        //handle notification action If application is closed
        firebase
            .notifications()
            .getInitialNotification()
            .then(notificationOpen => {
               //action here
            })
            .catch(error =>
                console.log(
                    "Home.js : " +
                        "firebase.getInitialNotification error : " +
                        error
                )
            );
    }

    //function for handling opened notification on foreground / background (not killed / closed)
    onNotificationPressed = notificationOpen => {
        if (notificationOpen) {
           // action here
        }
    };


    }