I am trying to build a test app that would detect a given set of iBeacon deployed in a few physical locations. The detection should be done in the background, and make a call to a server following a certain logic.
Apple's rule of thumb is using the same UUID for all of my physical locations:
The UUID is shared by all locations.
This allows an iOS device to use a single identifier to recognize any of the stores with a single region.
Each specific store, San Francisco, Paris, and London, is then assigned a unique major value, allowing a device to identify which specific store it is in.
I found the call for setting a region with a given UUID, but did not find what object is returned when the UUID is detected, and what fields are returned.
Where does the app get the major/minor value when iOS detects a beacon with a given UUID?
When using monitoring APIs, you only get a CLBeaconRegion object in the enter/exit callback from CoreLocation. A beacon region defined by this class typically doesn't represent individual beacons, but a range of beacons based on wildcard identifiers.
Because of this, if you use wildcards in your region definition (as is typical) you actually can't see which specific beacon triggered a region entry. To solve this problem, you must combine both monitoring and ranging APIs at the same time. If you monitor and range simultaneously, CoreLocation will give you a callback in the didRangeBeacons beacons: [CLBeacon] inRegion region: CLBeaconRegion method with an array of all the CLBeacon objects it saw.
Because the callback with the array of beacons arrives once per second, however, you will need to add custom logic to do something only once when beacon first appears, if necessary.
Since you want background detection, it is important that you do both ranging and monitoring simultaneously. Even if you don't put anything in your monitoring callback because of the lack of specific beacon information, you need to do monitoring just to get your app woken up in the background on a new beacon detection. Then, you will get ranging callbacks for approximately 10 seconds before your app is suspended again.