Quick access data outside of closing
I am new to iOS. I have a request how can we access data or variables inside a closure. Below is a code snippet.
self.fetchData() { data in
dispatch_async(dispatch_get_main_queue()) {
println("Finished request")
if let data = data { // unwrap your data (!= nil)
let myResponseStr = NSString(data: data, encoding: NSUTF8StringEncoding) as! String
}
}
}
I want to get myResponseStr outside, like self.myString = myResponseStr
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1 answer
You must use the closure of the completion handler in a function that calls fetchData
, for example:
func fetchString(completionHandler: (String?) -> ()) {
self.fetchData() { responseData in
dispatch_async(dispatch_get_main_queue()) {
println("Finished request")
if let data = responseData { // unwrap your data (!= nil)
let responseString = NSString(data: data, encoding: NSUTF8StringEncoding) as? String
completionHandler(responseString)
} else {
completionHandler(nil)
}
}
}
}
And you would call it like this:
fetchString() { responseString in
// use `responseString` here, e.g. update UI and or model here
self.myString = responseString
}
// but not here, because the above runs asynchronously
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