Is interprocess communication relevant on the iPhone or iPad? Because there's NSPipe available...
The stock iOS sandbox does not allow an app to start another process or communicate with any other process on the device directly (except using a public API).
You might be able to use pipes for communication between threads within an apps single process space.
Not for the current iPad (which I'm typing this on), but iOS4 supports multi-tasking so presumably it is more relevant there?
Related
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/
Is it possible to identify devices around me that have their bluetouth enabled?
I don't need to communicate with them, just know they are there.
I am looking for something similar to android's BluetouthDevice.startDiscovery()
Is something like this possible?
Apple turns out to be very restrictive about Bluetooth communications for iOS platform.
Focusing about a native application with Xcode (but not PhoneGap based - PhoneGap is a Xcode plugin that allows web apps to be converted into native ones; btw it gives a quite nice but limited access to underlying hardware resources) for a iOS device to communicate with bluetooth devices (even with discovery actions) the following conditions have to be met:
-) The device you're trying to discover must be equipped with Apple Bluetooth authentication chip (you can ask to Apple directly for the MFi program);
-) Internally your app must declare a protocol name (e.g.: net.yourcompany.proto0) which the devices you connect with must conform to;
-) You must use Apple's External Accessory Framework to establish communication with such devices.
In short, by this procedure Apple guarantees that the only Bluetooth communications an iOS device can establish are just with authorized and certified Bluetooth devices.
I've gone 400 Mph about this thing but I hope it can give you some pointer to start your search.
The topic is too wide to be treated here in its full length.
One thing you might want to look into is Bonjour and NSNetServiceBrowser.
You can publish a service and also search for other services around you. There are ways to run Bonjour in the background (http://stackoverflow.com/questions/6345554/bonjour-in-the-background).
The only limitation with this approach is that everyone else would also need to be running the app as well. Also, by default Bonjour discovers over both WiFi and Bluetooth, something else you would probably need to look into.
Is it possible to communicate two instances of an app:
In nearby devices (Android or iPhone)
Without user intervention (aside from starting the app once)
Without internet (but not network) connection?
How?
Android to Android?
iPhone to iPhone?
Android to iPhone and vice-versa?
Let us ignore the issues associated with implementing the network communication at the application level and focus on the system design problem your question raises.
You want an application on one device to connect to another associated application on another device without any user intervention/interaction beyond launching the device. In order for this to work your system is going to need a 3rd party separate from the two devices/applications that provides a lookup service.
What will need to happen is each application will need to communicate with this service, ask for the data regarding other device it should connect to, if it exists, and then attempt that connection. This is basically how a bittorrent tracker works.
Keep in mind that there's quite a bit more involved in the implementation than that simple scenario suggests. For example, the proper registering/unregistering of devices, registration timeouts, security, etc.
Unless I misunderstand your question, you should be able to just use standard sockets (TCP or UDP depending on your needs) for communication between any/all devices. For iPhone, you could probably use the NSStream classes and for Android you'd use the Socket classes.
Can the new NFC feature be an answer to this?
What I need is to have a simple screen in this Mac app that just prints a string as the iPhone is transmitting strings through the WiFi network.
This string is simply a string value from a slider being adjusted up and down by the user on the iPhone. The data will be sent to the Mac app and then the Mac app will receive this signal from the WiFi network and simply print the values.
This is a constant connection. I'm not trying to sync once. I'm trying to listen to the iPhone device from the Mac to see if the iPhone is sending any more strings as the user slides the UISlider up and down from the iPhone app.
How can I create the client side? Do I need to use Bonjour or something?
In my answer to this question, I provide a link to a sample application that has a Mac component and an iPhone one. These components communicate between one another over a WiFi network, with changes in a label on one being reflected in the other. This is done using Bonjour discovery and the standard networking APIs.
With simple modifications, this could be used to send the continuous updates you need for your particular case.
Use the CFNetwork framework, you can use bonjour for discovery and then handle a persistent connection through native sockets for passing data back and forth.
http://developer.apple.com/library/ios/#documentation/Networking/Conceptual/CFNetwork/Introduction/Introduction.html
Here is an excellent tutorial to get started, its for iOS but CFNetwork is available in OS X too.
http://mobileorchard.com/tutorial-networking-and-bonjour-on-iphone/
I'm in the process of planning out a personal project that will be a media player and one of the things I would like to do is be able to dock my iPod touch (or any iPod or iPhone) and control it and play music off it like the speaker docs do that you can buy.
I found some information while searching around online for this but my question is can I make up a cable and use the serial protocol from any device or does Apple have this locked down so only certified/approved devices can communicate this way?
If you are looking to do this for yourself, I would recommend jailbreaking and the following resources on the web. These describe some methods of the Apple Accessory Protocol, and include some parts (at sparkfun) to execute. To get approved for the Apple method you need a corporation (or similar structure) and even legal counsel before you can get approved to even see the agreement you have to agree to in order to join.
http://nuxx.net/wiki/Apple_Accessory_Protocol
http://www.sparkfun.com/categories/101
There are even some great articles out there such as:
http://courses.cit.cornell.edu/ee476/FinalProjects/s2007/awr8_asl45/awr8_asl45/index.html
Good luck!
EDIT:
Since this is a relatively popular post, keep in mind that you can now use Bluetooth 4.0 LE for serial communication without approval from Apple (other than AppStore approval).
https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts/AboutCoreBluetooth/Introduction.html
Only devices in the Made for iPod program which use Apple's proprietary authentication chip can communicate with the External Accessory framework on the iPhone or iPod touch. Such devices must also expose a protocol that iPhone applications can use.
It is a reasonably involved process to be approved as a Made for iPod vendor of products (similar to the App Store approval process, but for hardware), but it has become a lot easier than it used to be. With iPhone OS 3.0, Apple has opened up the program to many more third parties than just the usual large accessory providers.
In your case, I'd actually wait and use another vendor's iPhone-controllable stereo. Manufacturers are just starting to come out with hardware controllable via iPhone applications, so it's only a matter of time before one of the larger accessory providers creates something like what you want. If they expose a protocol for controlling the device, all you'll have to do is write your application to control the device via that protocol.