Question

I want to create an application which will be notified by server for new events. (lets say I have a shop and I need to inform all my iPhone users for my sales or something like this) Users who will download my application and run it and then put it in background wil have to be notified by this. Im quite new to iOS and Objective-C but if im not wrong this could be done via apple push notifications. Ive been reading about this and found out there are some providers that let you send this notifications. My question is, are there ways to create your own notification “center” in lets say c# and send notifications to iPhone-s by yourself, also if this could not be done are there any free providers?

and another thing. In objective-c app you have to subscribe your app to listen to that kind of events. Could you create app in phonegap or some other technologies so it will work with notifications? could you lets say embeed your app in objective-c (like web app in objective-c)

Answer 1

For sure you can do your own C# program that will push APNs to your clients (in fact I did that myself in many apps). What you have to understand is that the architecture of APN has 2 critical facts:

1. APNs are best effort, so no guarantee that they will reach every time.
2. APNs can not hold a lot of information with them when they reach your client (they have a limited number of bits, refer to the Apple documentation).

Due to these facts you might need to have your own server application (also could be in C#) that will handle sending the real information to the clients and will make sure that the data reached your client as well. Needless to say, this server application should sit and run on a real server. Maybe due to this fact some developers start looking for a third party solution, but personally I prefer not to use a third party and I do everything myself.

Other than having your own server application, your iPhone app will need to have some sort of database (probably SQLite3) to store the received news and display them later on.

EDIT: Answer of your questions in the comments below:

For the first question “why iPhone app must have sql db”. In fact it is not a must, as I said in my answer above, it is probable or a possibility. To know if you will need a database or not this depends on the nature of your app itself. For example you might be pushing text and images to your clients and in that case you can not fit such data in the payload of the APN. Another possibility, you might want not to lose the sent notification even if the user discarded the APN message, you might want to show it again when he opens the app later on… So the nature of the app decides whether you will need a server or not.

For the second question “you said you dont need to send notification via third party”, let me clarify something in my answer. As an Apple developer I don’t consider Apple servers as third party. Put differently, the real APN will only be sent via Apple servers and we can not change this fact (nor do we want to change it too). So at the end of the day the real APN will be sent to Apple servers and Apple servers will work on delivering it to the actual client. What I consider a third party is someone that has his own server, you send the message you want to him, and then he sends it to Apple servers. In that case there is someone between you and the Appl APN servers and this is what I called a third party, and this third party can be avoided as your C# code can directly connect to the Apple APN servers and ask it to send the message to the client. I hope I clarified my point.