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Start your free trialMarcos Reboucas
12,890 PointsAny idea what's wrong with my closure?
func fetchTreehouseBlogPosts(completion:{(data:NSData!, response:NSURLResponse!, error:NSError!)->Void in})
import Foundation
// Add your code below
func fetchTreehouseBlogPosts(completion:{(data:NSData!, response:NSURLResponse!, error:NSError!)->Void in})
2 Answers
Roberta Voulon
5,792 PointsI think a ton of people are stuck on this, I finally got a hint from somewhere and it worked for me, so I'm re-posting this where I can: What made it work for me in the end was wrap the signature in outer parenthesis like this:
typealias BlogPostCompletion = ((NSData!, NSURLResponse!, NSError!) -> Void)
func fetchTreehouseBlogPosts(completion: BlogPostCompletion) {}
It's really silly, I was stuck on this for days, I didn't even know this is correct syntax, and they're not necessary!
Richard Lu
20,185 PointsThe problem here is that your defining the closure. To fix this problem you have to declare it, like this:
import Foundation
// remove the 'in' keyword
func fetchTreehouseBlogPosts(completion: (NSData!, NSURLResponse!, NSError!)->Void) {}
When you pass the closure onto the function, it should look like this:
fetchTreehouseBlogPosts {
(Data, response, error) -> Void in {
// do something
}
}
Let me know how this works out for you (:
Marcos Reboucas
12,890 PointsHello Richard and thank you for helping. Unfortunately it didn't work for me. What I'm doing is:
import Foundation
typealias BlogPostCompletion = (data:NSData!, response:NSURLResponse!, error:NSError!) -> Void
func fetchTreehouseBlogPosts (completion: BlogPostCompletion) { }
But I'm getting: Make sure the method is named fetchTreehouseBlogPosts and has the correct syntax!
Also the preview:
swift_lint.swift:7:45: error: expected ',' separator typealias BlogPostCompletion = (data:NSData!; response:NSURLResponse!; error:NSError!) -> Void ^ , swift_lint.swift:7:45: error: expected type typealias BlogPostCompletion = (data:NSData!; response:NSURLResponse!; error:NSError!) -> Void ^ swift_lint.swift:7:45: error: expected ',' separator typealias BlogPostCompletion = (data:NSData!; response:NSURLResponse!; error:NSError!) -> Void ^ ,