Difficulties converting to Swift 3

Question

After converting from Swift 2 to Swift 3 (even after converting edit-> convert -> to current swift syntax) I am getting lots of errors. Especially:

I am shown total 90 errors for my project which was working fine in Swift 2 before i downloaded this beta Xcode 8.0 and converted to Swift 3

Is this a conversion mistake I am making?

Solution 1

Most of them are easy fixes, simply by tapping the red button, and having Xcode fix it for you! Others include:

CGRect

Swift 2:

let frame = CGRectMake(0, 0, 20, 20)

Swift 3:

let frame = CGRect(x: 0, y: 0, width: 20, height: 20)

CGPoint

Swift 2:

let point = CGPointMake(0, 0)

Swift 3:

let point = CGPoint(x: 0, y: 0)

CGSize

Swift 2:

let size = CGSizeMake(20, 20)

Swift 3:

let size = CGSize(width: 20, height: 20)

CGRectGetMidX

Swift 2:

CGRectGetMidX(view)

Swift 3:

view.midX

CGRectGetMidY

Swift 2:

CGRectGetMidY(view)

Swift 3:

view.midY

UIColor

Swift 2:

let color = UIColor.redColor()

Swift 3:

let color = UIColor.red

"NS"

Swift 2:

NSTimer
NSData
NSError

Swift 3:

Timer
Data
Error

UserDefaults

Swift 2:

NSUserDefaults.standardUserDefaults().//something

Swift 3:

UserDefaults.standard.//something

Solution 2

And always remember to use the helpful "Fix all in Scope" function which can be found at Editor -> Fix all in Scope

Solution 3

I was converting a project and Xcode was not helping me with any fixes so I resorted to a couple of regex search-and-replaces:-

CGPointMake\((.*),[ ]*([^\)]+)\)
CGPoint(x:$1, y:$2)

CGSizeMake\((.*),[ ]*([^\)]+)\)
CGSize(width:$1, height:$2)

Note they are not aware of nested parentheses , but probably good enough for 90% of cases.

Comments

[niravdesai21]

@EricD i want to know is the method to convert code i use edit-> convert -> to current swift syntax is correct or not. If there is a better method then just to help me with that. thats all i asked for.

[Eric Aya]

@niravdesai21 Yes this is the right command. This command does most of the work, but it's up to you to do the rest. Xcode is just an IDE, not a magical thing. :) Read the Swift 3 docs if you're lost with the changes.

[Pranav Wadhwa]

Also, it is possible that the conversion didn't work right. Try converting it again, even if it gives you a warning that the file was already converted to Swift 3

[DG7]

I had over a 100 errors when I converted. Come to find about 80% of the errors were resolved when I updated my libraries. In particular I was using Swifty JSON. I uploaded the latest file version and voilà, the rest was manageable stepping through code.

[Tyler Hack]

This helped me out a lot, while I was working I found one more that was a recurring change CGRectGetMidX && CGRectGetMidY Swift 2: CGRectGetMidX(object) || CGRectGetMidY(object) Swift 3: object.midX || object.midY

[Pranav Wadhwa]

Thanks @TylerHack I'll include that in my answer. Glad to help!

[nights]

i have hundreds of CGRectMake etc, how is that easy to change? maybe by regexp, but even so quite dangerous

[Pranav Wadhwa]

@nights try converting it again. I believe the default conversion will fix it.

[nights]

tried a hundred times and it will not convert anything :[ now making changes manually...counting days

[Vitya Shurapov]

Also size, point and rect with 0 as the values, it can be done like this.

[Vitya Shurapov]

let size = CGSize.zero, let point = CGPoint.zero, let rect = CGRect.zero