On 8 April 2015, Apple released Xcode 6.3, updating the Swift language to Swift 1.2. We spent some time working through our recent book, Swift Development with Cocoa, to make sure we knew how the changes impacted the example code, and to provide updated code as needed.

We're pleased to say that the required changes are minor! We've pushed a full set of updated example code to the GitHub repository, available here. We've also made a changelog, listing the differences between the code examples in the book, and the current best-practice with Xcode 6.3:

• NSApplicationMain(C_ARGC, C_ARGV) has been replaced with NSApplicationMain(Process.argc, Process.unsafeArgv)

• Several methods that were implementations of protocols had the optionality of their parameters changed. For example, the applicationDidFinishLaunching parameter originally had a parameter of type NSApplication!, which has now changed to NSApplication.

• Several properties changed from being optional to non-optional, or vice-versa.

• Swift now has a "forced cast" operator, as!, which is used when down-casting from a class. We've update the code to use as! when appropriate (such as when downcasting from NSObject to CLLocation)

• Changed NSCalendarUnit.DayCalendarUnit (which was deprecated) to NSCalendarUnit.CalendarUnitDay

• Changed "countElements" to its new replacement, "count".

You can also find the changelog in the GitHub repository. The changes are all very minor, thanks Apple! If you have any questions, don't hesitate to contact us! Thanks for buying our book, we love hearing from readers.

These webcasts have both happened already! We'll be posting the content here within 24-48 hours! Thanks for watching!

We're doing two webcasts with O'Reilly Media in the coming week. They're both free and the content we cover is a lot of fun. They are:

• Five Swift Essentials – covering five core components in your programming arsenal when building software for iOS or OS X with Swift, Apple's new language.
• Build a Game in Less Than an Hour with Unity – covering everything you need to build a simple asteroid shooting game with Unity, the amazingly powerful game engine.

Both webcasts are free, and you can register for them via the links above. We'd love to see you there! 

Our new book is finally out, in early release unedited ebook form! Today Swift Development with Cocoa was released by O'Reilly Media.

We're really proud of this book (which we wrote with our friend and frequent collaborator Tim Nugent), and now's a great time to grab it – O'Reilly is running a 50% off promotion on all the great new iOS 8-related books until 5AM PDT on 25 September 24!

The code samples for Swift Development with Cocoa are available on GitHub too, if you'd like to play with some Swift.

While you're at it, check out our friend Tony Gray's new book, Swift Pocket Reference – Secret Lab wouldn't exist without his encouragement and support, and he's written a damn fine pocket reference for Swift!

Stay tuned for more books, as well as the final release of these Swift books. Let us know if you have any comments on the early release editions! 

YOW! Connected

We just got back from speaking at the YOW! Connected mobile and Internet of Things conference in Melbourne – it was lots of fun (and a nice successor to Swipe Conference, which we spoke at both years that it ran).

We presented two, completely different, sessions:

• How to build games for children – on the design and production of mobile games for younger children
• Building iOS apps for IoT devices: a case study of the Holiday by MooresCloud

The slides from the IoT talk are available on SpeakerDeck now, and the games for children talk will be available soon.

We'll definitely be at YOW! Connected near year – it was awesome!

/dev/world/2014

Up next for us is /dev/world/2014 – Australia's oldest iOS and Mac developer conference. We're helping to organise /dev/world this year, and it's shaping up to be bigger and better than ever! It's happening later this month: September 29 and 30, in Melbourne.

We've announced three great feature presentations:

• Marc Edwards, from well known Mac and iOS developers Bjango, and co-host of Iterate, the mobile design podcast.
• Tom Greenaway, from Kumobius, developers of wildly successful mobile games such as Duet and Time Surfer.
• Paul Fenwick, science educator, public speaker, and occasional pirate, from Perl Training Australia (although he won't be talking about Perl!)

We've also announced many fantastic speakers, including people from Google, Canva, AccessibilityOz, Appbot, Reckoner, Fairfax, and Shiny Things, amongst many others!

There will be workshops on the use of Xcode for development, as well as one on Swift, Apple's new language (we're running that one!)

As we said in our previous blog post, Secret Lab wouldn't exist without /dev/world – we've been attending since 2008, and it's part of what helped us build a company and learnt to design and create great software. 

If you're in the developer community, and you're interested in iOS, Mac, Swift, or game or app development in general, you don't want to miss this conference.

Updated 12 September 2014: The playground is now updated for Xcode 6.0 GM! We'll be running a workshop on Swift at /dev/world/2014 as well, if you want to learn more!

We've been spending the last week learning Swift, Apple's new programming language. So far we're very impressed! We put together a playground to test out, showcase, and learn the new language and syntax. We thought it might be useful, so we've put it up on our GitHub. 

Let us know what you think! If you'd like to learn more about Swift, iOS programming, and even Objective-C (which you should still learn, in our opinion), check out our training!

Don't forget to check out our brief thoughts on WWDC 2014 as well.

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Some quick thoughts from Secret Lab on the mind-blowing collection of WWDC 2014 announcements from Apple.

OS X Yosemite

Pretty! Made simpler. Not super sold on translucency, though.

Handoffs and Continuity is awesome. Will be super useful. Devs get access to this too. Reminds us of the excellent “Send to Chrome” feature in Android. Only really polished.

iOS 8

Not a huge amount of new stuff, visuals wise; however, there are some awesome behind the scenes changes.

Custom Actions, Photo Editing, Sharing Options can all be provided by apps. You can make your app provide services to other apps. This is AWESOME - it’s going to make the app ecosystem quite a bit richer.

Android’s had this for some time, and it’s great to see it in iOS.

The ability to put widgets in the notification center is also great, lots of devs are going to make some great stuff with this.

Being able to share documents between apps without having to copy them is going to be Super Nifty. This has been a real weakness of iOS until now.

Swift

WOW. Apple developed an entire language, wrote all the docs, and wrote all the supporting tools for it, without it leaking. This is really impressive.Can’t wait to use this.

The language is very modern. Its syntax feels like a mashup of Python, Haskell and Ruby.

Interoperation with Obj-C is rather nicely handled. They’ve directly translated ObjC’s arguments-are-embedded-into-method names approach into named parameters. The goal was clearly to make it as painless as possible to work with both languages in a single project.

Something that’s interesting is it’s completely opposed to Objective-C’s way of doing things is that, while ObjC allows sending messages to nil (thereby making it safe to not have to do null checks), Swift instead guarantees that all values that are not Optionals are non-null. Optionals are a very cool feature: in other languages, the concept of “nothing” is usually represented by a special value (for example, Lua’s ‘nil’ value), or by convention (for example, in C, the value 0 means ‘nothing’). This creates its own problems; if you use a special value, comparing it to other objects means you have to do type conversions, and if you instead use the convention of zero meaning null, you have to do checks. Objective-C goes some of the way towards helping with this: it defines ‘nil’ as a special value that’s represented a zero pointer, but calling methods on it is safe because the runtime automatically returns if it notices you’re trying to call methods on nil.

This is nicer than crashing, but it can lead to problems, since if an object you’re trying to work with is unexpectedly nil, you’ll get bugs. Not crashing bugs, but weird behaviour bugs.

The Optionals system is nicer. In Swift, a value is either guaranteed to be a valid one, or else is explicitly known to sometimes be nil.

For example: if you’re converting strings to integers, your code looks like this:

let theString = "123"

let theInt = theString.toInt()

In most languages, the ‘toInt()’ method would return a value that represents ‘not valid’, such as 0. But in Swift, it returns an optional int - that is, a value that MIGHT represent nothing, but if it doesn’t represent nothing, then it’s GUARANTEED to be an integer and nothing else.

This makes things quite a bit safer, since the compiler’s able to do more checking, and is able to reason about your code better.

Swift is filled with this kind of thing. Another example: in C and similar langauges, the assignment operator (=) returns a value, like this:

a = b = 3 // sets both a and b to 3

In Swift, that doesn’t apply. This means that the following is actually a compiler error (it’s just a warning in ObjC):

if x = y {

…

}

We’re not huge fans of the range operators: a...b means “range from a to b, including b” and a..b means “range from a to b, not including b”. Notice that they only differ by a single period. That’s going to lead to bugs, due to typos.

The mutability of variables depends on whether or not the variable is declared as a constant or not. This is nicer than Objective-C, which has two different classes for each type based on whether it’s mutable or not (ie NSString vs NSMutableString)

This only applies to strings, arrays, dictionaries, and other low-level things. We’re still going to be stuck with NSURL vs NSMutableURL for a while.

Playground is super cool. Reminds us of IPython, in that you can figure out your code without it having to be run inside a larger app. This is going to make development a lot faster.

App Store

Being able to show videos and make app bundles (with discount) is going to be neat. Not a huge game changer for us, but any increase in app store functionality is good.