I am working on a project that went open source. The project is a GPS based strategy game where players attack eachother using missiles.
The app is supposed to send notifications to the user's phone when they are under attack. The problem is, right now the app uses workmanager to send a request to the game server once every 15 minutes (the limitation imposed by android) to check whether their player is under attack, which completely misses the attack most of the time. Truly an unreliable method.
I notice that apps like Discord, Facebook Messenger, etc, are able to send notifications the instant a new message is sent without fail. How do they do this? Is this something I can use for my app?
You use push messaging (like Firebase Cloud Messaging) to push alerts from the server to the client when one occurs.
Related
I am building my first Android app and need to know how I could use push notification.
My project is a home alarm system and also I have built my own local web server. Now I want to push a notification from my server to my Android app when an alarm appears in my server.
Currently my garage doors use the MyQ app and when the garage door opens or closes I get a notification on my phone, I want to implement the same thing in my app.
I've been reading about the Google Firebase Cloud Messaging but it seems exceeding my need.
If you need push notification on your cell phone then you definitely need to integrate your app with Google Firebase. (or at least that's the right way of doing it).
Alternatively, there is something called as local notifications & background process in Android you could do long polling to check if the garage door is open (probably every 2 mins or something). However, I don't recommend that as it can drain your mobile battery.
Also I recommend using Flutter as oppose to using Native Android. As there are some pre-built libraries for android and Google Firebase integration.
Take a look at this Youtube video - https://www.youtube.com/watch?v=2TSm2YGBT1s
Ouh, maybe thats a little bit too much for starting with android - nevertheless I want to help you.
You need a communication protocol between your server and your phone (i.e. Firebase as you mentioned or Websockets).
If your server sends a message to you client (your phone) you have to create a notification. (Android Developer Guide). That's the theoretical part. You will also stumble across a lot of
challenges with
asynchronous programming.
Firebase might actually be the simplest option. You could build your own web socket service too, but that would probably be more than you need. See this previous question for more options: Android push notification without firebase
Android has some services that communicate with firebase to receive notifications.
You'll need to implement a service on top of your web server (using backend languages such as Python, Node.js, PHP,...) so it can send notifications when an event happened (like the door closed) witch isn't a simple way for a beginner.
then your web server sends a message to firebase and tells it to send a notification to my client.
so I highly recommend using firebase because of the simplicity of usage. otherwise, you should implement a separate service on your android phone to get the notification (if you want to run it locally) also as explained do the backend side.
I want to create a notification system provider that is not based on Google services or similar. In fact, I want to get information about its overall architecture and needed Android sdk functionality.
The most weird point for me is to understand how to send a notification to an Android device.
I mean, how can I identify the Android device on which my application is installed from millions and millions of other Android devices on the Internet?
And how do I send information to him?
Should I use sockets for this or similar stuff?
simple answer: YOU CAN NOT
before everything else i should correct your question, pusher and FCM are not in the same group at all! you can build somthing like pusher or oneSignal or etc but you can not build something like FCM/APNS
you should understand three simple yet important sentences below:
when you want to pull anything from place_1(e.g. api) to place_2(e.g. browser_client) you most have an identifier of the place_1_resource (which commonly is the uniform-resource-locator of api)
when you want to push anything from place_1(e.g. notification_central_server) to place_2(cellphone_client) you most have an identifier of the place_2_resource
you must know the differences between a real server push with server-push-like technologies like long-pulling or ... and you should be aware that what is intended in this concept is a real server push not any kind of pulling with a push jacket!
if you don't have any identifier for a cellphone which you want to send it a notification, your server dont know where to send that notification so we need a resource_identifier_like for cellphones which is actually a device_token_like and you have just one approach to get this device_token_like and that is the FCM/APNS
FCM is like a dns server containing all identifiers of every android device that google supports (almost every android device) and APNS is just the same but for apple devices
note1: even if your app can obtain it's corresponding device device_token_like it can not be used for push notification if its not registered on FCM/APNS
so when you get that device_token_like identifier of your desired clinet_device now you can use different approaches for sending sth to that clinet_device. there are several approaches like SSE, Webpush, HTTP_server_push, Pushlet and etc but none of these approaches supported by mother_companies of these devices, the only approach that is completely supported and standard is the same approach that FCM/APNS official websites suggests
for example an iranian Incorporation named najva uses webpush to send notifications because of USA sanctions but webPush method works good on browsers and android devices but they didn't even apear on an apple devices
finally i should say that i admire your curiosity to less using anything from a benefit_based Inc. like FCM/APNS in your developing but i strongly recommend these articles and books for you cause i think you didn't learn enough:
wikipedia of push technology
story of some guy who tries to make his own push notification service
Push Technology A Complete Guide - 2020 Edition
Data Push Apps with HTML5 SSE
Short, direct answer
You can't (At least till you create your own ROM)
TL;DR, Reason why?
Before you build your own push notification server, you first need to know how it works internally in android.
Whenever you/your server sends a push notification message to the android client, the SDK processes it and shows you the notification. But when your app is not running (or being killed), your app cannot respond to it since it was not running. In such a case, your notification message is sent to a system service which is known as Google play service. For this even to work, you will first need to bind your app with Google play service and that is what FCM does. FCM SDK registers your app to the operating system service on the first initialization. That FCM service is opened to a port which listened to the incoming message from the server and when it receives the message, it publishes a notification on behalf of your app with a PendingIntent containing the data. Then the PendingIntent is delivered to your app when the user clicks it and then finally your app process the data (or the push message)
So basically, for your server to communicate with the client, It first needs to communicate with the FCM service and for that, FCM gives you a token which identifies the application to register with the internal Google play service.
Simplified furthermore, the workflow is as follows:-
Server send push message ---> FCM ---> Google play service,
If your app is running, it is directly handled by the client SDK So, Google play service --> Your app
If not, then it is delivered by the service itself using PendingIntent So, Google play service --> PendingIntent --->| Publish notification
Totally impossible, Workaround?
There is nothing like impossible because an absolute impossibility doesn't exist. Saying impossible generally means near to impossible. (This is similar to math where also we say tends to infinity because no one has achieved it yet).
To make it work, you need to somehow bind your app to the Google play service and you can't because Google hasn't exposed any direct API to do that. The only possible way is using the FCM ;-) (Bad luck again). So the only possible way is to build your own custom ROM with a custom push service that acts as a client for your Push server and a Server for your Push client (which is your app).
Since the above option tends to impossibility, you have to choose a workaround.
The best among the worst workarounds are:-
To make a malicious SDK.
Malicious because it needs to keep the app running in the background with a service that is connected to a WebSocket endpoint of your server. (Harder in new android versions).
Make use of a database where your push notification is saved and your app checks it periodically using AlarmManager.
Hope you have got the point.
After discovering that WhatsApp probably updates notifications about every second I began to wonder what the best combination of battery life and keeping users up to date by notifications is.
The company where I work right now is really afraid of sucking the battery life. So they want the fastest sync to be around a quarter. Meanwhile WhatsApp updates every second. So is what our company doing the right thing? Or can we just like WhatsApp check for new updates every second because it doesn't suck that much battery life?
That extensive network usage will surely be very expensive for battery and even for data usage. If you need frequently updated data in your app, in most of the cases it's a bad practice to send HTTP request once per 1 (2 or even 5) seconds.
A good way to receive and update any kind of notification (wether it's Android system notification or some notification badge inside your app) is using Google Cloud Messaging. You'll have to implement it on both server and client side. You will need to register your app package name in Google Developer Console and retrieve an API key. After you do that, your app will be able to receive push notification from GCM server. The flow of receiving a push notification looks like this:
You register current device to GCM system using provided SDK and it generates you GCM unique identifier of current device
You upload this key to your server (if you have user profiles in your app architecture, it's a good idea to store it in current user profile)
Once something important happens on server, say, user gets a new unread message, your server takes the GCM unique identifier from user profile and sends a notification to GCM server
GCM server sends this data to user's device by using this identifier and delivers the notification to your implementation of a BroadcastReciever. After that it's up to you what to do with this data: create a system notification or/and use this information to update UI of your app.
It is just an overview of how does Google Cloud Messaging work, there are tons of articles about how to set it up and implement into your project, for example, this one. This solution might look way more complicated than just sending HTTP request every second, but your potential users will be thankful for saved battery and data limit.
Also, if you want to make Android system notifications, you may want to use Parse library which wraps GCM and makes implementation a bit easier.
I am currently building a messaging application that allows users to send and receive messages on their Android mobile phones over an internet connection to each other. I have decided that I do not want to use polling because it means that a user may not receive another user's messages as instant as possible. I have my own server available for use.
I am currently tied between using Google's Cloud Messaging for Android platform in order to send the notifications from the server to the Android device. The other option is to keep a live TCP connection between my server and the Android device via a service, and send 'keep alive' messages every 5 minutes for example.
From your best opinion, what is the best way to do this - or is there a better way? I don't want to use third parties apart from Google to do this. There are similar answers available, but they don't address this specifically.
Alex
using Google's Cloud Messaging for Android platform in order to send the notifications from the server to the Android device.
This is not a realtime notification either; the notifications may be delayed longer than you experienced with polling. Also GCM is meant for broadcasting messages to a number of users, not for targeting a message to one specific user.
The other option is to keep a live TCP connection between my server and the Android device via a service
I don't know how many users you are expecting, but this may not scale. You are limited in the number of TCP connections to one server.
No need to re-invent the wheel here, use an existing implementation such as XMPP.
Take a look at this:
https://pusher.com/docs/client_libraries
https://github.com/pusher/pusher-test-android
It may be what you're looking for
I want to know the complete working mechanism of the mail apps for android.
Actually I build an android app for big data product.It has a feature which will shows the notifications (list view) .
Now I want If new notifications come in the DB It should ring a bell and in notification bar of the android phone it should show, As in case of Mail apps, as soon as we got new mail a notification comes in notification bar.
NOTE: android server which needs to be queried may not contain internet.This App works on intranet also.within a company network.(without the internet)
So I want to know the mechanism to implement this feature.
1) Whether i should run a background service which will send query to server on regular time interval.
2) Or any other services like push notification.
I just need a clear idea about working of these type of system.So that I can implement this in effective manner.
Thanks
Obviously the best solutions would be to use PushNotifications. This is how GMail does it, and this is how every email app, or messaging app has to do it.
Polling the server will drain the battery, and will also make extra (unnecessary) data traffic, which is something you don't want your app to do .
You should get started here : Google Cloud Messaging. In my opinion it is very easy to setup, and I recommend using GCM, instead of all the other alternatives like Parse and so on.