iphones/Beacons & swift

What will be covered

TODAY

• Intro to XCode
• A simple BLE project: http://git.io/ve9gE
• Using the Storyboard designer (maybe)

NEXT WEEK (or so)

• Handling REST with Alamofire and SwiftyJSON
• Cocoa Pods

XCode

1. Check out Sample Code at http://git.io/ve9gE

2. This code needs changes (as it is pre Swift 1.2)

Swift Design principals

• Better NIL value handling via optionals and strict initialization
• Strongly (statically I suppose) typed
• Use ObjC & Swift within the same project (via Bridging Headers)
• Functions are first-class citizens; Closures
• Memory Management and memory saftey (no GC, no ARC, no unsafe pointer casting)
• Assertions

Swift optionals

scala has it too

​f: a function which returns an Array or NIL

​func f(arr: [Int]) -> [Int]? {

 if (arr.count < 1) {
    return nil
 } else {
    return arr
 }

}

Swift optionals

​Array? is of type OPTIONAL (yes that's a type)

​Use UNWRAPPING via ! to get the actual value

​var i = f([1,2])![0]   //OK - unwrapping works
var i = f([1])![0]     //Booom - f returns NIL

Swift optionals

​Typical pattern.

​if (let i = f([1]) {
    println(i.description)
}

​You can also use

​if (f(<some array>) != nil) {
   // do something
}

Delegate pattern

Delegation is a design pattern that enables a class or structure to hand off (or delegate) some of its responsibilities to an instance of another type.

​Application Delegate. 
- viewDidLoad






CLLocationManagerDelegate​.

There are important events in the life of your application that happen out of its direct control. These include things like launching and terminating. Your application needs to know when these things happen or are about to happen, so the iPhone OS will automatically notify your AppDelegate by calling the appropriate method (e.g. applicationDidFinishLaunching, applicationWillTerminate). That's the main purpose of the AppDelegate.

Things that should be run once a BLE event is triggered.

Core-location Delegate

​Responding to Location Events

Pausing Location Updates

Responding to Region Events

Responding to Authorization Changes

Deplyoing to Appstore

This app will not be accepted by Apple.