Can two iPhone aplications communicate with each other? - iphone

Is it possible for two iPhone apps to communicate with each other by any means like sending messages etc?
EDIT: Also is there any way a system app can communicate with our app?
For example: If I want to play a sound when I receive a phone call, then is it feasible?
Thanx in advance.

Do you mean in realtime? On the same device?
Of course there are uncountable ways to do IPC (pasteboard, -[UIApplication openURL:], via a web-service). The best way to send data depends on the actual use case.
For now two apps cannot run at the same time, so realtime communication would not be possible on one device.

I think that not directly, they're only allowed to access it's own sandbox. You could approach that using Push on both Applications, using an intermediate server to transfer the data between the two apps.

Direcctly it is not possible at all
With intermediate Server they can..
i.e.
One application sends message to server
That server sends same message to Second Application via Push Notification

Related

Can an iPhone app act as a server to send messages or push notifications?

I want to write an iOS app that can act as a client and a server to other iPhones over the cellular data network (i.e., without a typical centralized server). The goal is to share series of about 200 short event messages, one at a time, from the iPhone server to multiple iPhone clients by some means of notification. Apple Push Notification service would be fine for such notifications, but there is no need to use it specifically.
I think sending push notifications from one iPhone to another is possible by connecting to gateway.push.apple.com from the serving iPhone as described in the Local and Push Notification Programming Guide, but I can't find anyone else discussing this approach (maybe it's too obvious?).
The reason for all this is an attempt to avoid the overhead of infrastructure. If this isn't feasible, alternatives which minimize or avoid additional hardware are welcome.
Requirements:
Communication must be [strictly] over cellular data network
Wi-Fi isn't available
Bluetooth doesn't have enough range
Unidirectional communication with an iPhone server multicasting to many iPhone clients
No jailbreaking
Ideally the serving phone's battery will be able to handle this without a recharge
Update 5/4/11 2:12 AM EST: Just to be clear, I don't have any particular requirement to use APNs; I thought it may have been feasible in this setup, but from the discussion below, it sounds like that's not the case. However, I'm still interested in any other system that could help me achieve the same end result with some type of message passing or similar form of communication.
Theoretically you should be able to write a iOS app that can connect to the APNS and send notifications to other devices running your applications. However, your main problem will be to actually acquire the 'tokens' of other devices. When you have a centralized server doing the job, its always online and thus, the clients can 'talk' to it via http and register them self (giving their tokens to the server in the process). Thus the server knows the client token and it can use them to send notifications to the clients via APNS.
However this is not possible in the scenario you are talking about. But this is not to say its impossible. May be you could use an email account X, to store all client tokens. Every client will send a email to this account with their token in it. So when a another 'client' want to send a notification to another client, it can find out the token by reffering to the inbox of the email account (you can cache this stuff and optimize it in a zillion ways of course).
But the point is some how a (third party(ex: email service provider)/your own) server that is online 24/7 will be involved in the process.
Let us know how you progress with this. It would be interesting to know.

communication between smartphone

how can I communicate with another smartphone per example in a game?
I'm developing in objective-c, I need to pass/receive informations about positions of some elements on the screen, but I've not ideas of how i can do this, can you give me some tips? Do i need a physical server with a socket open? and how can i manage the connection?
Thanks for any help.
Jonathan.
Look into the peer-to-peer methods of GameKit. It's designed for multiple devices to communicate with each other. iOS only.
One phone can't readily programmatically talk directly to another phone. Well, you might be able to get phone A to send an email or SMS to phone B, but then phone B's app won't be able to act on the notification. (Since you mention obj-C I assume you're using iOS)
So you'll likely have to have a central server help out. Assuming apps running on both phones. Phone A can make an http request to the server; while phone B polls for a possible response. It can use a comet-like technique to reduce polling overhead.

Send location coordinate to another iPhone

I am trying to write an app that communicates with another app. I just want to see the other person on my map. Is this possible ? I can handle all the map details if I can get the coordinates in real time. Any advice on communicating with other iPhones would be great. I donot want to use Apple Push Notification service.
You can achieve this by having some web service running that allows the iphone to get and send information to it. Look around this site, the question of how to make requests from a service through the iphone has been asked many many times. Specifically look at NSURLRequest/NSURLMutableRequest documentation ...hope this helps
I would suggest you look into Bonjour services for the iphone. If you want one instance of your app to communicate with another instance of the same app on another iphone, then this is probably what you want, unless you want to use gamecenter.
With bonjour services you can advertise a service on the phone while the app is running and have the other iphone connect to that service and send it some data.

iphone app communication without using webservices

I want to send some Text plus a image from one iphone application to other iphone app but restriction is I should not use a web server in between communication,Is there any way to fulfill it ?
Details: There are two independent devices and could be far enough say out of network. My requirement one app adds some text with a image and sends it to another iphone which can be at any long distance , and the app installed in another iphone will read that info and image into itself.
Actually there is a solution that meets your needs — and that fits to bbums answer:
Create a HTTP-Server on the iPhone, using cocoahttpserver. than you will ask some webservice like whatismyip.com for your public ip. with this your iPhone can be connected worldwide.
But very likely ur wifi-network is not forwarding your port to the iPhone. Ash.
And even if: Now it gets difficult. How to publish your ip from one phone to the other? hmmm... — I got it: I will exchange the information in a centralized space! In the web!
... wait — that would be a Webserver.
You see: Without any kind of server in the Web the users would need to exchange ip manually and have full admin power and knowledge about the local network.
So IMHO bbums answer is the only way to go.
PS: I am working with http server running on iPhones. In local network that works great, especially with bonjour. And you can use them over distance network — but only with reconfiguration of your router — something you shouldn't force your user to do
There is far from enough information to provide a specific answer.
two apps on two different devices?
are the two devices on the same network?
are the two devices both on WiFi?
do you need the user to receive a notification or something if the app isn't running?
If on same device, you can define a custom URL handler in the destination app and then openURL: in the source app to pass the data over. Encode your image and text into the URL, but be careful of size limitations.
If on different devices, there are many possible solutions, but answering the above questions will be critical to actually knowing what solution is appropriate.
Given your comment -- two apps, different devices, arbitrary networks -- then you are going to have to have some kind of server in between. Note that the recently added Game Center does have the ability to rendezvous two users, but it has a very particular user experience that may not be appropriate to your needs.
I would suggest that you investigate using push notifications to notify the receiving user of the availability of content. As for moving the content between, no direct connection is possible and you will have to have some kind of store-and-forward server in between. And, yes, a web server is going to be the easiest possible solution simply because HTTP is ubiquitous these days.
If there's no network of any kind available, but both parties have amateur radio licenses, then hooking the two devices up to HF packet radios might work.
THIS is super EASY.
I would code up some software that can turn data into modem signal, like the good old dial up modem. The device would actually make those annoying buzzing sounds.
You get the phone number for your friends nearest landline and call him.
He places his iPhone near the phones receiver in listen mode and you connect to his phone using your audible modem.
Bingo, via the power of sounds you have sent data which is decoded on his device and all for the very cheap price of a phone call, there are pretty cheap these days especially if you use Skype.
Easy Way (relatively speaking)
A way two apps on different networks can communicate without setting up a web server of some sort is as follows.
Use an existing third party storage system like DropBox.
Each app would need the login and password for your DropBox. Then both apps can read and write files that the other app can see.
An existing app that does this is a shopping list app called ShopShop.
The app on my phone and my wife's phone both link to the same DropBox account and the app keeps the shopping list synced up when one of us adds something to the list.

Send data to a SPECIFIC iPhone application through mobile network (No Internet)

I am looking for a way to send data to a SPECIFIC iPhone application without going through Internet... thus using the mobile network.
Thanks.
No chance. There's only two things the phone is actually receiving: calls and text messages. Both cannot be used for what you like to do, since neither can be routed to any app.
You can't even really keep an open socket to allow connections through the internet, since the new multitasking is not really multitasking and allows listening for new data only for a few types of applications, voip clients for example. But you didn't want internet anyway...
Best you can do is text the phone a URL whose schema is registered to your app.