We have several apps on our android devices that signal notifications even when the device is off. An example, if we are watching an eBay auction on our PC, and we have the eBay APP on the device, even if the device is off, we get a "chime" and a notification on the top of the display about the auction. Another example, GasBuddy will chime a notification when gas prices are going up in our area.
How do these apps do this, even with the app actually not running?
- Are they "automatically" running in the background?
- Are they periodically, every few minutes as an example for the auction purpose, automatically logging into the internet and checking for an update?
- Is somehow the "service" such as eBay or GasBuddy "pushing" some sort of signal to the device?
- Do they have "another" app running in the background looking for notifications?
They use the concept of Push Notifications. You can use Google Cloud Messaging(GCM) for push notifications.
In short how it works is, the app when launched for the very first time, or when the user logs in, registers an id with the server. The server then at a later time sends a signal to the device (using that id) using push notifications. You need to handle those push notifications in your android app.
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I am developing a IOS/android app which will used by our vendors, the app will send notifications to the vendors timely, i wonder if there is a way that the vendor MUST click "accept" or "read" for every notification, even he/she disable the notification permission for this app.
so, all of my perpose is the vendor must ready the notification and the server side should be able to know who is not read. the vendors should not has an execuse that he/she do not get a notice while the policy changed.
There is no way to 'force' a user to open a notification, but if you use a Push Notification service (AppBoy, etc) most of them have metrics and can track who has opened the notifications. So if your vendor comes back and says they never got it, you can say yes you did, and which device they opened it on. You could then continually send notifications to those who haven't opened it until they do.
This won't work if they have notifications disabled, though. No way to get past that without building a messaging system into your app.
I am pretty new to the mobile development scene and there is a very basic question to which I cannot seem to find the answer. Here is the scenario.
I have a mobile application. That application is connected to a server that I own. To use the mobile application, users have to login using unique credentials. Now lets say there are certain events on my server, about which I want to notify a particular mobile application user. Can my server proactively send a signal / data to the particular mobile app instance [using sessions data perhaps] so that a notification can be displayed on their screen?
Polling by mobile application towards the server to look for such events is not allowed / feasible.
I can speak to an iOS solution. Android surely has very similar functionality.
There are 2 ways to accomplish this:
Silent push notifications
Background fetch
A silent push notification can be, well uh, pushed to devices without alerting the users. This means that upon reception of the notification, the app can start downloading what it needs from your server. You will need to set up proper backgrounding for this to work properly. Otherwise, the notifications will be queued up and will only take effect when the user opens your app the next time. Start here for push notifications. The payload you send is what controls the notification.
Background fetching is process where your iOS app gets woken up by the operating system (iOS) periodically to allow you to perform a task. This task can be fetch data from a server or anything else you want pretty much. This is probably the best of the 2 solutions given that push notifications are not guaranteed to be received and this puts the onus back onto each device to fetch their own data as opposed to you creating a whole back-end system to perform the push notifications. Start here for background fetches.
You mean something like push notifications? You can read this tutorial (or any other tutorial on google) about how to implement push notifications in your app:
http://www.vogella.com/tutorials/AndroidCloudToDeviceMessaging/article.html
Lookup about push notifications on each of the platforms you're talking about.
Plus look into some live web apps, two that come to mind are meteor.com and nodejs
Can Pusher messages be received on Android/iOS app when the app is closed or the phone is turned off?
What i expect to happen...
When phone is on & app is on, it's pretty straight forward from the Pusher docs on how to react to pusher messages sent to the app.
When phone is on & app is closed, the phone should receive a notification that something has been sent to the app.
When phone is turned off, a notification should be received by the phone when it's turned back on to notify that something has been sent to the app.
Are these even possible? If yes, what are some suggestions to lookout for? If no, what can be some workaround?
When an application using Pusher moves into the background on iOS and Android the connection to Pusher will likely stay active for a few minutes. But eventually that connection will be closed. You can't stop that happening within your application (although there may be a "hack" around stating your app is a Voice app when submitting to the Apps store).
Therefore, you should monitor your application moving to the background and put a fallback in place to delivery messages to the phone when it's not connected.
Please see How get pusher events when the iOS app go to the background? for libPusher (the Pusher iOS library).
Here's an extract from the Android Processes & Threads Lifecycle docs on a "Service Process":
A process that is running a service that has been started with the startService() method and does not fall into either of the two higher categories. Although service processes are not directly tied to anything the user sees, they are generally doing things that the user cares about (such as playing music in the background or downloading data on the network), so the system keeps them running unless there's not enough memory to retain them along with all foreground and visible processes.
So, running a Pusher instance in such a thread is a viable option.
However, there will still be occasions where the user goes offline. In that situation your server you can detect if a user is online by querying the Pusher HTTP API or by using WebHooks where your server can be instantly informed if the user has gone offline or come back online.
Using the mechanisms above you can facilitate smart notifications; if the user is online (the app is in the foreground) then send the message to them by Pusher, if they are offline (the app is in the background) then use an alternative mechanism for delivery (native Push Notification, SMS or email).
I am creating a app in android 4.0.3 i.e ICS version, which connects to the server when client gets login into the app.I am trying to get status of an client when he gets online or offline through server & seen onto the app screen.I am unable to proceed. Can anyone say me:
Is it possible to get the status of an user through server?
1-- How to proceed for first step...?
2-- How should I get a response from the server that the client is connected & viewed to other client example - when we login into skype our status shows available with green radio button, In same way how can I get it.?
It ll be very help full, If anybody guide me.
Many Thanks..
I'm assuming you're trying to develop a chat app ?
If this is the case, try using an XMPP library. XMPP is widely used for chat apps, including Facebook chat (and Google talk I think) and there are plenty of open source libraries available.
Otherwise, if you only want real-time notifications as a part of a bigger picture, try using push notifications. Google supports Cloud to Device Messaging (C2DM) for android. It allows to have push notifications to a specific device without you having to deal with persistent connections, battery and CPU use .etc.
C2DM approach comes down to this. When a client connects to your server, get a list of his friends and their 'C2DM IDs' and fire a C2DM push to their devices. This push is delivered to your app, and you can respond to it by firing a notification, or update UI .etc. (Your app doesn't necessarily have to be running. Push notification is delivered via a specific broadcast, and your app can register a receiver for it to wake up.)
Keep in mind that there is a quota for C2DM messages per device, per app and also a limit for the payload per message. So you're not supposed to send massive files via this. Just a notification to your app, so it can call your server and get an updated list, instead of polling.
You can get more info on C2DM and code samples here. https://developers.google.com/android/c2dm/
Hope this helps.
You may have moved on, but I'm posting for anyone who would run into this one in the future.
Firebase is a good solution to use in this scenario, if the app is always running when you want communication to happen. (It will not wake up your app as C2DM/CDM does, unless you have a service running all the time and still wouldn't wake up if the device is asleep... AFAIK)
It may be useful for some scenarios, but may be not for a chat app as you want the device to wake up when a message arrives.
Note that they have limitations on the free subscription though.
Is it possible to send push notifications to an android application without using Google server: C2DM?
So, I would like to have my own server which sends notifications directly to the app, but I'm not sure how are the notifications perceived by the device, because the device needs to receive notifications even if the app is not running and the notifications should appear in the notification center.
I think that the guys from www.airpush.com have managed to this, but I'm not sure how.
Can anyone help me with this please?
UPDATE:
Also I would like to know how to display the notifications in the notification center if I don't use C2DM? And if it is possible to configure the notification center to receive notifications from my server even if the user deletes the application developed by us, application which registered that device to receive notifications.
I want to send 3-4 notifications a day, but these notifications need to appear in the notification center and they should go only through our server. How can I configure the notification center within the app to make requests on my server for push notifications.
Thank You!
There is a solution from UrbanAirship called Helium push. According documentation Helium:
Works on Android 1.6 and higher
Does not require a Google Account
No default pushes per day limit
No default pushes per minute limit
Works on Amazon devices (e.g., Kindle Fire)
End to end Urban Airship support (i.e., API to to device)
Best throughput
The problem is that you need development app key for using this one.
Take a look at MQTT:
MQTT stands for MQ Telemetry Transport. It is a publish/subscribe, extremely simple and lightweight messaging protocol, designed for constrained devices and low-bandwidth, high-latency or unreliable networks.
It can be used (and was used in some applications) to implement custom server push solutions. One of the most well known applications using MQTT is Facebook Messanger.
You can easily find more information on MQTT in the Internet, e.g. in this SO question or in this blog post.
According to the FAQ on airpush.com, they're not using real push notifications but rather polling the server a few times per day. One reason I think this is a viable solution for you as well is that Android's C2DM apparently makes use of the Google Play Store, so it won't work on devices distributed outside of the Google eco-system. With over 5 Million Kindle Fires having sold already, that is worth thinking about.
From Airpush FAQ:
When executed once from the main activity of an Android™ application, the Airpush client utilizes Android™ OS's AlarmManager framework to schedule ongoing server polling events a few times per day. If an ad is polled from the server it is cached until optimal display time, which is algorithmically determined by the server.
Without using C2DM there's not option for a "real push notification". Because (afaik, correct me if I'm wrong) an android device registers at google (they can still deinstall malware from your phone via remote) and with this ip they are able to do a push notification. All other solutions could tend to be a "register at a server, keep the connection alive and wait for requests" or something and tend to be more battery-inefficient.
Parse has an excellent push notification service for Android, very easy to setup. More info here: Parse Android Notification Doc
If you want the user to only receive 3-4 messages per day and your messages are not bound to specific arrival times, you don't need pushing mechanisms.
Just create a service in your app that checks your own web service 5-10 times a day. If there is new data, make your app display it in the notification center.
If you don't want to have a service running all the time (like many messaging apps do), you can set up alarms (using the Android AlarmManager framework) that wake your app up regularily to check for new messages to display.
And if it is possible to configure the notification center to receive
notifications from my server even if the user deletes the application
developed by us, application which registered that device to receive
notifications.
That sounds like you want to write a virus or root kit ;-) You could use e-mails for your messages instead.
UPDATE 2013-12-30:
As just noted in my comment, rebuilding what GCM does is not a nice approach. It's enough when Google Services already load the device with this functionality. If your goal is just that Google does not see what messages you send to your users, you might aswell encrypt them. For Google not being able to actually read your messages, the client app should generate a key and send it to your server. All messages you send via GCM can then be encrypted using that key.
If you just want to circumvent Google's restriction on the amount of messages sent to users, you could pack multiple messages into one GCM notification and show them one after the other. But then again, we are back at some kind of polling solution as described before, with the exception that the user does not need to have internet access when you want to show the messages as they are cached on the device.