I am completely new to push notifications, FCM and Ionic.
I have followed this tutorial to create a push notification using Ionic 2 and it works.
It feels like there is no use of device-id (generated at the client side) at the server side in this ionic doc.
I am unable to understand how to send different push notifications to different users using the same app and same server code?
Also whats the purpose of FCM (Server key and Sender ID) here?
What's the exact workflow, does it works like a web-socket?
Thanks for the guidance :)
1. It feels like there is no use of device-id (generated at the client side) at the server side in this ionic doc.
The device-id (aka the Registration Token) is the identifier for the specific device you intend to send the push notification to. Saving this value in your App Server is important so that you can send push notifications specifically towards it (should you decide/need to) later on.
2. I am unable to understand how to send different push notifications to different users using the same app and same server code?
As mentioned above, this is where the device-id (Registration Token) comes into play. For each device, there is a corresponding unique id, which you'll have to specify in your payload.
3. Also whats the purpose of FCM (Server key and Sender ID) here?
You can refer to the FCM docs for these:
Server Key - A server key that authorizes your app server for access to Google services, including sending messages via Firebase Cloud Messaging. You obtain the server key when you create your Firebase project. You can view it in the Cloud Messaging tab of the Firebase console Settings pane.
Important: Do not include the server key anywhere in your client code. Also, make sure to use only server keys to authorize your app server. Android, iOS, and browser keys are rejected by FCM.
Sender ID - A unique numerical value created when you create your Firebase project, available in the Cloud Messaging tab of the Firebase console Settings pane. The sender ID is used to identify each app server that can send messages to the client app.
To keep it short, Server Key is for authenticating, Sender ID is for identifying from which project the message is coming from.
4. What's the exact workflow, does it works like a web-socket?
Not really. Having a web-socket means that having the connection always active until decided to be closed, where in FCM (or even before, GCM), the lifecycle is like this:
Lifecycle Flow
Send and receive downstream messages.
Send a message. The app server sends messages to the client app:
The app server sends a message to GCM connection servers.
The GCM connection server enqueues and stores the message if the device is offline.
When the device is online, the GCM connection server sends the message to the device.
On the device, the client app receives the message according to the platform-specific implementation. See your platform-specific documentation for details.
Receive a message. A client app receives a message from a GCM connection server.
Send and receive upstream messages. This feature is only available if you're using the XMPP connection server.
Send a message. A client app sends messages to the app server:
On the device, the client app sends messages to the XMPP connection server. See your platform-specific documentation for details on how a client app can send a message via XMPP.
The XMPP connection server enqueues and stores the message if the server is disconnected.
When the app server is re-connected, the XMPP connection server sends the message to the app server.
Receive a message. An app server receives a message from the XMPP connection server and then does the following:
Parses the message header to verify client app sender information.
Sends "ack" to the XMPP connection server to acknowledge receiving the message.
Optionally parses the message payload, as defined by the client app.
I am unable to understand how to send different push notifications to different users using the same app and same server code?
It's your task. Your message must contain all neccessary data (i.e. userId) so your app knows which of the users are target for that message.
Related
we created a Chat application with a Client and a Server project.
Clients can send messages to the server and the server and the server forwards it to other Clients (like a Chat application should do)
FCM is implemented in the Client project. Users can send Notifications to each other.
How can I use the Server for sending Notifications? Can I just write the Code for sending Notifications in the Server project (Server does HTTP Request with User token etc.).
Idk about that because I think the project should be somehow registered to FCM to use the services.
I only find tutorials about sending Notifications from App to App, not from Server to App.
For example in this scenario:
User installs app, then creates account and gets confirmation email from the server
, then clicks on confirmation link (app is clossed or in background)
, then gets notification that the account is ready
I think this is not possible with using FCM only in the app project
I was wondering how android push framework is able to distinguish data recieved via GCM and forward it to the appropriate android application for which it was intended ?
Can anyone let me know how it is done ?
You question : how android push framework is able to distinguish data recieved via GCM and forward it to the appropriate android application.
From your question it looks like you willing to know about data
workflow & Client Server architecture that exists in applications
which are using the GCM service.
As per google’s documentation “Google Cloud Messaging for Android (GCM) is a service that helps developers send data from servers to their Android applications on Android devices”. GCM is a service provided by Google for developer that helps developer to send data from server to any number of Android devices.
Simplified Application Specific Work-flow:
The push notification can be broadcasted either to the mass audience
or a select set of users. Mass audience is targeted when the
notification has to be sent about a marketing campaign. A subset of
users are targeted when a personalized information has to be sent.
The below steps explains how push notification works on android devices:
First android device sends sender id, application id to GCM server
for registration.
Upon successful registration, GCM server issues registration id to android device.
After receiving registration id, device will send registration id to our server.
Our server will store registration id in the database for further use.
Whenever push notification is needed, our server sends a message to GCM server along with device registration id (which is
stored earlier in the database).
GCM server will deliver that message to respected mobile device using device registration id.
This can also be understand using following figure
An Example Workflow:
So, from above images it easy to understand that whenever the android
application is first installed by the user, then it registers itself
to GCM server, and obtains unique GCM ID, then it's our Host servers
responsibility to keep this newly registered Registration ID of the
android user into Database, and then it will be used whenever server
side application willing to send the message to that particular
android user.
So, let us consider one case; suppose an Server wants to send Some data to Android User, which has already registered it's GCM ID 1234567 when it's first time installed, and as it's in the server's database the server application will fetch it from DB, and simply make a HTTP POST request to the GCM server in JSON format, which will have registered user's GCM ID along with the data to send , in same way the GCM Server has the record of all the Registered GCM/Android Clients, it directly forwards that message to the intended android user, and android app in user's phone will raise and Notification alert, to indicate an push notification has arrived.
Hope This answers an question!
GCM stands for Google Cloud Messaging.
Every push notification receive on any Android device is sent by the GCM only.
sender -> GCM -> Android Device
when sender sends an push notification then it goes to GCM. GCM receives that push and forward it to particular Android Device by its Unique device id.
GCM can't deliver Push without Unique Device ID.
while implementing push notification there are two important things, application key and server key ... these are unique Keys.. using these keys GCM identifies the application to whom push notification is related
I am trying to make a simple messaging app that has a mysql and php server with an android app. My back end revolves around mysql to store and php to communicate from the database to the device and vise versa.
Now, what I am trying to accomplish is this: sending device->GCM->target device.
What I had in mind was that the database I created stores the gcm Id for all user. That way, when a user wants to send a message, their app sends a message to my database to be stored and retrieves the targets gcm Id and then sends the targets gcm id to the gcm servers to create the push notificiation. When the target receives the gcm message, it sends a response to the database to receive the actual sent message.
Is this possible, and how would I go about doing this?
I already have a gcm receiver implemented from here:
https://github.com/codepath/android_guides/wiki/Google-Cloud-Messaging
No. Don't do it.
For any internet connected device (server or mobile) to request a push to a device, it needs to send a POST request to the GCM address (https://gcm-http.googleapis.com/gcm/send) passing the server API key and the device GCM reg id which should receive the message. And having any of those values available on a device is a security risk for your application.
Having your registration ID, means ppl could easily "copy" your ID and start sending messages from their servers on your behalf.
The GCM device registraion ID, means anyone could start spaming your users, and you certainly don't want that.
You could look into GCM Upstream (https://developers.google.com/cloud-messaging/upstream) but that only means your client code will be easier, as it's as simple as calling gcm.send(String);, but you still have to handle that on your server application.
The correct way is to have on your server a table that maps userId with gcmRegId and have devices send to your server messages to their desired userId. Your server should process one device "send" message and create a push to the other device. That logic should be fairly simple on the server side, after you already have a whole chat application developed.
I am currently using GCM to push notifications to both an iOS and Android version of my app.
With Android, I am able to process any message I send from the server client side, and then decide what I want to do with it. For example, I can receive a request, check client-side if the user has push notifications enabled, and THEN send a push notification from the client side.
The question is: Are there any client side methods of sending push notifications for iOS, similar to Android?
To receive message, an iOS application needs to register with both Apple Push Notification service (APNs) and the GCM connection server. When a client app registers with GCM, it receives a registration token, which it must then send to the app server (the APNs device token is not sent to the server). The client app must store a boolean value indicating whether the registration token has been sent to the server.
You can follow this documentation on how to set up a client app on IOS.
Based on this SO question, It is very simple to implement APNs and GCM. You can follow this steps
When APNs (iOS Devices) and GCM (Android Device) registers for Push Notification on Apple and Google Server it generates a unique token for every device.
After that, you need to save that device token, with your device id or user id (unique id on your server for device) and the OS of device.
IOS device is sending this information on your server (backend) you can use this JSON format- {"token":"abcdedfgehik2bd3d3ff3sffssdff","os":"iOS","userid":34}
This is how it will work.
You request device token from APNs as usual.
You need to send that token to GCM service with provided API.
Then GCM sends back a another token.
Then send that token to app server.
App server can send notifications using that token.
Try also to check this for more information.
I'm building a little android app that will connect to a server.
My app would use a simple post to send a message to my server, and I'm using Google Cloud Messaging for the server to send a message to my app.
I built a registration page, an email confirmation and a connection page but now I wonder how to lock the communication between the server and the app.
This is the protocol I have in mind ( let's take the simple exemple of app to app message) :
App send post infos to the server with self infos (like name and auth_token), destination user and the message
Server search the apps which belong to the destination user and use curl to forward the message to GCM
GCM send the message to the destination apps
How can the server be sure that the name, auth_token etc the server receive are really from the sender ?
Let the server generate the authentication token when the client is doing the registration and send this back to the client. The server now knows the [client - token] mapping.
Every time the client wants to send a message, it also sends the authentication token which the server can look up and check. The client does not even have to send his or her name, the server should know this.
To prevent MITM attacks, use a secure connection (HTTPS).
Although there are lots of solutions to secure the connection, when you are using GCM for your downsteam messages, I recommend using the new Google Cloud Messaging API which supports Upstream Messaging (from client to server).
It is very fast, reliable and secure.
Here you can find the docs
You should only change your server side from HTTP to XMPP.
Here you can find the docs.