CODEWITHSUNDEEP
iosxcodeswift
commodore64
commodore64

Reputation: 11

JSON data - completion handler

I am new to iOS development and need help on below issue. I have the below code that downloads a JSON data from web and populates an array with that.

let urlPath = "……………………………"
    let url = NSURL(string: urlPath)

    let session = NSURLSession.sharedSession()
    let task = session.dataTaskWithURL(url!, completionHandler: {data, response, error -> Void in

       if (error != nil) {
            println(error)
        } else {

        let jsonResult: AnyObject = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: nil)!

        dispatch_async(dispatch_get_main_queue()) {

            for var i = 0; i < jsonResult.count; i++ {
                self.sales[i] = jsonResult[i]["daily_sales"] as NSString
            }
        }
        }
        })

    task.resume()

    println(self.sales[0])

at the end the app crashes since it does not wait for the JSON data to be downloaded.

What are the alternative ways to handle this?

Upvotes: 0

Views: 81

Answers (1)

Yaman
Yaman

Reputation: 3991

It crashes because of this println(self.sales[0]). You trying to display sales that are not even downloaded. Put this line at the end of your completion block and you should be OK

Upvotes: 1

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