Question

Well, my idea is to make an app that is installed on two or more devices. The main or “head” device can send out a call to one of the specific devices in the form of a push notification. The push notification could be preset or whatever. The goal would to be a simple notification system. All of the users who I am making this for have an iPad active and sitting on a desk in front of them. Imagine this as a doctor tool for calling the nurse into the room when the patient is ready. Tell me if this is clear enough.

How would this be done?

Answer 1

If I understand your question correctly, you want to develop an app that can push notifications to other devices.

The best way to would be to have a server and have the device sending the notification to send a request to the server. The server would then store it in a database. Then when the other devices send a request to the server to check for anything new, they would see that newest entry and push a notification to the phone.

In reference to Dave DeLong’s comment, this app might actually be good if people don’t want to use their minutes/texts/3G/4G, but instead only want to use WiFi. Also would be good for a small corporation instead of having walki-talkis. (That last part may be a stretch.)

Good luck on developing!

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In order to make the device check for new notifications from the server simply have it access a link during a set interval (maybe like every 5-10 seconds; an ideal situation would be to have a setting for users to change the time interval between checks):

hxxp://domain.com/checkForNew.php?deviceID=foo&otherSecurity=blah

Then have the PHP return some kinds of values that you may need. An example output would be:

fromID|toIDs|dateSent|message

On the iPhone you can get this content using:

NSString *googleString = @"hxxp://domain.com/checkForNew.php?deviceID=foo&otherSecurity=blah";
NSURL *googleURL = [NSURL URLWithString:googleString];
NSError *error;
NSString *googlePage = [NSString stringWithContentsOfURL:googleURL 
                                                encoding:NSASCIIStringEncoding
                                                   error:&error];

(This code can be found here: Reading HTML content from a UIWebView )

Finally, separate this string into appropriate variables and push the notification.