I have been trying to learn android programming following Ravi Tamada's tutorials - AndroidHive for weeks now. I created an app that performs Create, Read, Update and Delete actions (CRUD). Similar to this .
Now, what I want in my app is to have another feature that whenever there is a new data created and/or updated in the database, the app sends notification to other android phones that have the same app.
I've researched and come across Google Cloud Messaging, which AndroidHive also have a tutorial for. The way I see it is that it is only the server that can send notification to devices and GCM cannot do: "Device to another Device" For instance, "Device creates data -> send to database -> GCM sends notifs to other devices". Correct me if I'm wrong.
So I've searched again and found that you can use Smack for Instant Messaging app. Similar to something that I want my app to accomplish. But I'm having trouble understanding and implementing Smack to Java and Android.
So what I want to know is:
1.) Is it possible for GCM to listen to a device to check if the app has change the database and sends a notification to other devices that there is a change in the database?
2.) Do you have any "noob-friendly" article links on how to have a basic understanding and implementation of Smack in Java-Android?
Thank you.