Re: Swift enums and NSNotificationCenter
Re: Swift enums and NSNotificationCenter
- Subject: Re: Swift enums and NSNotificationCenter
- From: Rick Mann <email@hidden>
- Date: Wed, 05 Aug 2015 17:21:52 -0700
Thanks, I'll see what I can make of that. Still not quite as nice as being able to pass an enum to an NSNotificationCenter extension method, but partway there.
Would it make sense for Swift to just let you add method implementations to protocols (perhaps as a shortcut to the protocol-extension technique you used)?
> On Aug 5, 2015, at 17:18 , Charles Srstka <email@hidden> wrote:
>
>> On Aug 5, 2015, at 7:00 PM, Rick Mann <email@hidden> wrote:
>>
>>>
>>> On Aug 5, 2015, at 16:57 , Charles Srstka <email@hidden> wrote:
>>>
>>> I get that error any time I try to subclass *any* enum. I don’t think enums are supposed to be subclassable.
>>
>> Guess I'll submit a bug. Seems perfectly reasonable to do.
>
> Sorry for the delay; it took me a while to figure out why the line of code with addObserverForName was giving wonderfully helpful errors like “‘String’ is not convertible to ‘StringLiteralConvertible’” (grumble grumble).
>
> Anyway, what you want may be possible via a protocol extension:
>
> import Foundation
>
> protocol PostableEnum {
> func post()
> var rawValue: String { get }
> }
>
> extension PostableEnum {
> func post() {
> NSNotificationCenter.defaultCenter().postNotificationName(self.rawValue, object: nil)
> }
> }
>
> enum SomeEnum : String, PostableEnum {
> case Foo = "Foo"
> }
>
> let someEnum = SomeEnum.Foo
>
> let foo = NSObject()
>
> let observer = NSNotificationCenter.defaultCenter().addObserverForName("Foo", object: nil, queue: nil) { _ in
> print("notification received")
> }
>
> someEnum.post()
>
> CFRunLoopRun()
>
> Charles
>
--
Rick Mann
email@hidden
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