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iOS Build a Weather App with Swift Managing Complexity Callback Methods With Closures

Marcos Reboucas
Marcos Reboucas
12,890 Points

Could anyone tell me what's wrong with this closure syntax?

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 
^ ,
Callbacks.swift
import Foundation

// Add your code below

typealias BlogPostCompletion = (data:NSData!, response:NSURLResponse!, error:NSError!) -> Void

func fetchTreehouseBlogPosts (completion: BlogPostCompletion)
{
}

2 Answers

Roberta Voulon
Roberta Voulon
5,792 Points

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!

Trevor Moore
Trevor Moore
5,207 Points

Yep I was totally stuck on this, I thought I was misunderstanding the question. Very frustrating!