How do we detect if wifi becomes unavailable in iPhone SDK - iphone

Is there any way that we can programatically identify when the wifi of a user becomes available/unavailable?
My application requires exchanging messages between two different devices. It is working good in stable wifi setups. But if the wifi is unstable, I am having trouble in detecting if the other device is available or not.
I am not sure if this is expected, but my bonjour based NSNetService discoverer is not updating the available devices list automatically. This leaves me with a list of services that are not available for the exchange.
My line of thinking was to remove all the available services from the list and start a fresh search.
Please let me know if I am thinking in the right direction to solve the right problem.
Thanks in advance.
-Murali

Perhaps the Reachability sample code provided by Apple will help you in this regard. Although there have been people who say it hasn't been updated in a while, in which case, here is an actively maintained fork.
It seems like you can register for notifications so you can get frequent information on the state of the network.

Related

Peer-to-peer communication between iOS devices

I am trying to prototype a solution to a problem and am currently exploring multiple routes I could try. Is it possible for one iOS device, running a certain app, to communicate directly with another iOS device, running the same application - without the need to be on the same LAN?
Solutions I am currently investigating are using Bluetooth and ad-hoc wireless connections.
Ideally, the application when installed would ask the user for the required permissions, and then would accept and/or send data to/from another client after a handshake had happened.
My concern with Bluetooth is that 'pairing' would need to happen with every device, rather than happen in the background once the user has installed the app. I have a feeling what I am talking about isn't possible from what I've been reading elsewhere on Stackoverflow.
Take a look at Bluetooth Low Energy.
https://developer.apple.com/library/ios/#samplecode/BTLE_Transfer/Introduction/Intro.html#//apple_ref/doc/uid/DTS40012927
Here is another example,
https://github.com/KhaosT/CBPeripheralManager-Demo
You might also want to look into GameKit and peer-to-peer connectivity there.
I can't tell you anything about it, but you might try looking at iOS 7. If that's an option, I'd take a look. Can't talk about what it is because of NDA though.
Depending on what you need to communicate, you could try checking out this project, which lets you share arrays of strings between iOS devices over Bluetooth LE.
You don't need to "pair" the devices and it can still communicate while the app is in the background. SimpleShare
Hope it helps!
From the documentation of MultipeerGroupChat:
MultipeerGroupChat sample application utilizes the Multipeer Connectivity framework to enable nearby users to discover, connected, and send data between each other. This sample simulates a simple chat interface where up to 8 devices can connect with each other and send text messages or images to each other. Here you will learn how to bring up framework UI for discovery and connections and also how to monitor session state, listen for incoming data and resources, and send data and resources.
This is an excellent example at developer.apple.com here is the link
https://developer.apple.com/library/ios/samplecode/MultipeerGroupChat/Introduction/Intro.html
Also this tutorial from Ralf Ebert demonstrates how to use Multipeer Connectivity framework for peer communication should help you.
https://www.ralfebert.de/tutorials/ios-swift-multipeer-connectivity/

Share text between iPhone and other phones using wifi

Is it possible to send and receive data between iPhone and other phones such as blackberry or android over wifi. I am on the move it to create an iPhone app with the above functionality. Can any one has previous experience in this, or any sample codes to do this. I have searched a lot but couldn't find anything relevant.
you can do this by using a server application. So the iphone pushes the data to the server and the other devices are either getting push notifications or something similar or simply poll for the data.
Without a server, you have the trouble of finding the other devices. If its safe to assume they are all on the same subnet, then you could use a UDP broadcast to do this.
There's many ways of doing this, every one with its own pitfalls. So there's no generic answer to this question without knowing in more detail what's the purpose of it.

How do you get the charge status of a connected iPhone from the Mac?

In iTunes, you can see the charge status of the iPhone currently connected:
This updates as the phone charges, and even shows when the phone is done charging.
Is there a way I can discover the charge status programmatically from the Mac? Any programming language or API is fine.
I would recommend setting up a bonjour service in an App on the iOS device to communicate with the computer. The app will then communicate the changes in the batter status using the batteryMonitoringEnabled property of UIDevice. Take a look at the samples code here.
BatteryStatus Sample Code
And here is the class reference
UIDevice Class Reference
And finally Bonjour programming
Bonjour programming guide
As far as I know, the only official way to communicate with the iPhone over USB/Bluetooth is by signing up to the "Made for iPhone" program:
http://developer.apple.com/programs/mfi/
Unfortunately the documentation seems to be closed to registered members so I can't find out if the API for this is public or private. You could contact Apple to check before applying.
UPDATE : As mentioned, this might not work for Mac/PC <-> iPhone communication over USB. There are several apps that do things with the phone over USB (although usually for reading/writing files). I'd start by looking at the source code of those:
http://code.google.com/p/iphonedisk
This should put you at least in a position where you have a connection to the device and are able to send/receive commands. Everyone who's ever done this sort of thing has had to spend time reverse engineering the thing :) The jailbreak community might be able to provide some insight too, although having to actually jailbreak the device is probably unacceptable.

iPhone best method to achieve device-to-device communication

What would be the best method to achieve realtime device to device communication within an application? I've been experimenting with the Apple Push Notification Service but find it spotty at best for realtime messaging. Is there a way to utilize sockets for this or am I just stuck into using the APNS?
If you are a beginner, use GameKit.
When you get sick of that, use AsyncSocket.
GameKit is so simple a child can use it; AsyncSocket is probably the most beautiful library in all of networking on any platforms - incredibly easy to use.
In both cases, you will first use Bonjour (two lines of code) to "find" the other device.
Here is the full explanation...
Tablet(iPad/Android)-Server Communication Protocol
Critical secret knowledge about GK you will need...
Client/Server GKSessions
Another quick summary ...
Most effective way to do networking on Mac/iPhone?
For the record, APNS has absolutely nothing whatsoever to do with what you are trying to achieve! Utterly forget about APNS.
WHAT IS THE RADIUS? -----------------------***
Please note that BLUETOOTH ONLY WORKS over about twenty feet. (Ten meters.)
Please note that for a local WiFi connection, you must both be connected to the same local WiFi hub. WiFi hubs have a range of perhaps 20 meters only, say one house and the next house only (depending on how thick the walls are).
Please note that: IT IS NOT PHYSICALLY POSSIBLE TO CONNECT TWO COMPUTERS (OF ANY TYPE) OVER A COUPLE OF MILES.
There is no such networking device. (You could perhaps build one using say "ham radio" but to be clear it would be a completely novel, new research project that would take a large company years to complete.)
There is absolutely nothing that works like that - I'm sorry to tell you the bad news.
The ONLY two possibilties are Bluetooth and WiFi, and they work only over about 20 and 30 feet respectively.
So how do you connect two remote computers like that? The answer is, via the internet.
The only way to do it is with an internet connection. There is no 'direct' connection possible with any existing technology.
If you need to know more about how to connect two computers (say two iPhones) using the internet, you will probably have to ask a new question! You will be pleased to know it is very easy and will cause you little trouble.
Note that both iPhones MUST have a good solid internet connection. If they are more than say 30 feet away from each other, the ONLY way to connect to iPhones is via the internet. THey must each have a good internet connection, or there is no possibility.
I hope this helps clarify things!
You can use GameKit's peer to peer services (bluetooth)
Gamekit how to do p2p wifi connection in iphone
Check out Apples GameKit framework GameKit Or a sockets based networking look at AsyncSocket which also includes an iPhone demo.

How to identify whether the current data network is Edge or 3G on iPhone

Is there a way to figure out the current data network available on iPhone? Whether it is EDGE or 3G?
It works for me even if its doable using core telephony private framework. I am not bothered about app store submission.
I know its very simple to identify whether the user is on Wifi or CellData network. But not able to find a way to identify the network type among edge or 3g?
Pleas also comment if you know a good core telephony documentation/tutorial to refer to.
I've never investigated this, you could try to start from the Rechability
example from Apple
http://developer.apple.com/iphone/library/samplecode/Reachability/