Observer, Notification, Delegate swift ios8

I'm looking for some advice as how to best implement something which I think might be an observer, might be a multicast delegate or perhaps i'll just use notification enter.

I'm creating a DataManager class that connects to various data sources and produces a common data format.

Example:

We can generate a LocationMessage from either Internal Core Location, File Playback, Network Socket provided location, etc.

The data type returned is a LocationMessage that has a common format, which can also be converted into a CLLocation if necessary.

In my current "multi-delegate" model if you want to get location updates you have to implement the LocationConsumer protocol which defines

func didUpdateLocation(newLocation: LocationMessage) 
{
    println("\(__FUNCTION__)   \(newLocation)")
}

Then you would

//Instantiate a data manager
let dm : DataManager = DataManager()

//Register yourself as a delegate
dm.addLocationDelegate(self)

Internally when we get new location data the following is called:

    let closure = {
        (delegate : LocationDataConsumer) -> () in
        dispatch_async(self.delegateQueue) {
            delegate.didUpdateLocation(parsedLocation)
        }
    }
    locationDelegates.map(closure)

where locationDelegates is an array of [LocationConsumer]

Discussion

So, first off this obviously isn't really following a delegate pattern because you aren't supposed to have multiple delegates.

What I really like about the current approach, however, is it seems very clean to use a protocol in order to identify a class as caring about a specific data type. What I'm uncomfortable with, however, is "breaking" the standard delegate pattern.

From doing some reading I think the most appropriate approach would be to use a Notification Pattern, however, I feel from a coding point of view there is more maintenance involved (although I could be wrong). The simplicity of just implementing the protocol with this delegate method and calling addDelegate is lost with Notifications. I assume I have to specifically register for each notification i care about - correct?

I could not do something like:

class notificaitonClass : LocationNotifiee, WeatherNotifiee {

}

So I guess my question is

• 1: Have I implemented an Observer Pattern


• 2: What are the downsides of my current approach


• 3: Is there a way to define a swift protocol which will cause the class that implements it to automatically subscribe to a set of notifications


• 4: What would be a better approach ?

(Hope this isn't too vague)