I understand the basic concept of having a provider talk to Apple's Push Notification Server which then pushes the notification to the phone. Usually, the provider is an app server running on some machine somewhere completely separate from the app.
However, we don't currently have a separate server, and don't yet need one as everything is currently handled in-app. So, is there any way we can use the app itself as the provider to send a notification to Apple's server and thus to another phone?
Basic concept: we have a game and when a user completes 70% of the level, we'd like to notify his competitors that he's close to finishing the game (or that he has finished at 100%).
If it's possible, are there any security concerns with this approach?
P.S. The app already knows who the competitors are because it displays them in a UITableView.
Technically it's possible. If you include the push certificate with your app, and you have a way to send the device token of each device to all other devices that may need to push to that device, you can push a notification directly from one device to another.
However, in practice, that would require opening and closing many connections to the APNS servers frequently (you'll need a connection for each device, and every time a device loses network connection - which may happen often - you'll have to re-open that connection), which will probably cause Apple to block your app from connecting to their APNS server (since they would interpret it a DDoS attack).
Therefore you should use a server.
For future visitors to this question: we wound up ditching Amazon SNS since we spent nearly 8 hours and couldn't get it working the way we wanted. Instead, we setup Parse Push in rough 15 minutes with exactly what we wanted to do, so I would definitely recommend giving it a look.
Related
I'm looking at a way to receive (any form of) a notification in IOS (iPhone).
This is needed for a "nurse call" like project and should work regardless of internet connection.
But there are a few "small" restrictions.
It must work on a local network (no connection to the world wide web).
The app must work in background (not always opened).
The response time should be 1 minute max.
If it's of any help, I do have the possibility of using a local Apple MacOSX server.
Things I've tried.
I've looked at Apple Push Notifications, though I believe it will need access to the APNs (server). And can't work locally.
I've looked at keeping an "server" open in an IOS app, though this server will certainly be killed when the app is not in the foreground.
I've looked at the background mode "fetch", but it's not possible to set the frequency and it may just work once every 30 minutes.
I've looked at the Apple server, but I'd rather not use a local e-mail server since it's probably not fast enough and it'll not be possible to interact with an app this way.
The "Messages Server" seems to be interesting, but I'm not sure if I can receive those messages on an iPhone (from a local server, withouth the need of Apple servers).
We are designing a system that based on particular events on the server creates geofences for particular device. It is expected that the client (device) will be in sync with the server data, question is how?
Initial (most optimal) idea was to send a silent push to the device to notify it about new data, and trigger data pull. Knowing that this solution will work for Android OS devices, we though the problem can be solved in similar fashion on iOS. Unfortunately, my iOS dev told me that silent push are not reliable on iOS, and presented following discussion: Silent push notifications only delivered if device is charging and/or app is foreground.
Therefore, my question is how to keep the (geofence) data on the iOS devices in sync with server side?
We can pull, say every say 5 minutes, this solution is extremely inefficient, for most of the devices new geofences are changed rarely if at all, but our ‘power users’ need to have geofences updated very often.
We could push with some kind of silent push mechanism, but it has to be reliable.
Maybe some kind of persistent connection (tcp or better udp) but that seems like battery draining solution. Besides not reliable, the server would have to keep track of changing IPs which is not even possible on many cellular networks.
WebSocket. Also battery draining solution, that is not intended for background sync. Overkill for devices that really have the data updated rarely (like once a month).
Some commercial solution (PubNub or Pusher), but we would definitely prefer in house solution.
Are there any other solutions that are used in such cases? Maybe our approach with silent push is not right, but there is other build in Apple solution for such use case?
There's a fantastic service called Simperium with an iOS SDK that can help keep your info in Sync. I heard about them because I started using SimpleNote, a free note-taking tool that uses the sync service. They were acquired by Automattic, which runs Wordpress so the whole deal should be decently stable.
Hope this helps!
You can run your syncing operations in the applicationDidEnterBackground: method within AppDelegate. That's the solution I've always used as long as the syncing operation doesn't take too long.
Here you can also query your database for data changes instead of pushing a trigger to the device, which could get hairy with push notifications and aren't really their intended use. If changes in the data are found (or some boolean flag is checked) then initiate a data pull.
I'm not sure how much data you are working with but having a REST query every 5 mins is the way I'd go. Perhaps you can even switch it to a query each time you start up the app would be good enough?
We have an app where the user data needs to be sync'd with the back end server - each time we start the app it queries the backend server to see if there are any updates. We md5hash the data from the server and then we can just check our hash against the latest data - if it doesn't "match" then we pull the new data set.
In general, iOS doesn't really allow you to do multi-tasking the way you can do on android. Now, if you aren't releasing to the app store - and only using this as an in-house app you can get a little funky with things and run in a background mode.
Right now it seems that Apples Push notification Server is "Fire and forget". Surely there is some mechanism to improve the reliability, as other apps seem to have a higher rate of success (90%) wheras we are experiencing more of a 50%.
Apple's servers for uses I have seen, have been extremely reliable (along the 99.9% lines).
If you are having delivery issues, the real question is - how are you sending the push notifications to Apple's servers? It's easy for the server on your end to drop requests, or not be able to handle throughput - also possible with third party services that send notifications for you.
Also possible is messing up push provisioning on the client side so registration for tokens is not happening when you think it is, for instance new code is required for iOS8 to properly register for push notifications - older code will fail silently when compiled using the newer XCode.
I have a chat application developed by JS. I want to send PING to server once in a while. Its not a problem if app runs on fore ground. The problem is when user minimizes it or open another app. My app looses its focus and gets into suspended state.
I have following two use-cases.
To keep the chat session open I need to send PING to server (Its an IRC server) every X minutes even the app runs in background.
We also need to check for new messages (by ajax on a local http server) and add a local notification to the notification queue so when user clicks on it app can resume
I have found apple does not allow running apps in the background. if they allow they require special permission. I found some apps does it by requesting finite length execution time.
What is the best way to get highest possible background execution time? As a chat app can I request permission for voip, location or any other way ?
Note: the app will be running in an environment where there is no Internet. Hence push notification will not work here.
Update: After doing a lot searching I found background fetch. It seem background fetch will suite it. But still the problem remains, its not called in a timely manner.
This sounds like an interesting problem. From reading the various comments, it sounds like you want this to work when you're on a local network - so you have wifi, but the wifi router/base station isn't connected to the actual internet?
Because background refresh isn't going to be predictable - you'll never know when it is going to update - you might want to get creative.
You could look into exploiting iOS VOIP support, only without the Voice! Apple has some tips on VOIP here. VOIP basically uses something called SIP (Session Initiation Protocol), which is signalling layer of the call, and a lot like HTTP. It's this SIP layer that you want to take advantage of.
This isn't going to be terribly easy, but it should be achievable. Setup your app to use VOIP, and then look into something like PJSip as your SIP library. Then, on your local network have a SIP Server (I'm sure there are plenty open source implementations) that you can register your iPhone against (so your server knows where your phone is, pretending to be a VOIP phone). This should work, because it doesn't need to go through Apple as far as I am aware... And will run happily on your local network.
Then, the server can send a message via SIP to the handset, as if it were instigating a VOIP session. You app is awoken, gets the messages - ideally from the SIP message if possible - and then just doesn't start the session. SIP was designed just for creating sessions, not just VOIP. When I worked in Telecoms R&D (a long time ago) we were using it to swap between Text/Voice/Video, all using local servers.
You'll have to jump a lot of hoops to make this work, but it would be pretty awesome. I have never tried this actual use case - especially with iOS, but I'm fairly sure it will work. It is a bit of a fudge, but should get you where you need to go.
Good luck!
You can use something like PubNub to build this chat app with iOS using native Objective-C code, or with the Phonegap (Cordova) libs.
The beauty with using a real-time messaging network like PubNub is that when the app goes to the background, you can easily have the chat messages come in on APNS.
When the app is in the foreground, it can just receive them as the native (PubNub) message. And if it needs to "catch-up" with the messages it missed while in the background (but received via APNS), its trivial to implement.
Also, PubNub is platform agnostic -- so you can easily also use it on Web, Android, BB, Windows Phone, etc.
http://www.pubnub.com/blog/build-real-time-chat-10-lines-code/
http://www.pubnub.com/blog/html5-websockets-beautiful-real-time-chat-on-mobile-using-pubnubs-channel-presence/
https://github.com/pubnub/objective-c/tree/master/iOS
https://github.com/pubnub/javascript/tree/master/phonegap
geremy
We are building an enterprise class Work Order application where the users will often be in areas with no network coverage. We want to be sure that when they come back into coverage, any work that they have done on locally stored work orders is sent back to the server ASAP. This is easy to do if the user keeps the app running, but in our situation it is very likely that they will switch between apps, and the Work Order app may not be running when they come back into coverage.
We have thought of having the app fire an email to a server side listener when it senses that it is out of coverage. When the device comes back into coverage, the email should get delivered, and the server can send a push notification to the user to open the app. This feels like a bit of a hack... is there a better way to handle this situation?
As you already noticed, push notifications is the way to go, but even with them its not guaranteed that the user will send the data or even open the app.
I would suggest that you make the data itself expire after a limited time and alert the users when they minimize or even close the application.
You can also use local notification to alert about expiration.
So long as this is an enterprise application that doesn't have to be distributed through the App Store, you can abuse the audio background processing mode to keep your application running at all times. All you have to do is play a silent audio file on a loop as if you were a media player. This will keep your application running in the background, where you can retry connections to the server as you'd like.