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iOS

Posted by Kevin Gonzales
Kevin Gonzales
4,638 Points

Cant get passed this question.

Your job is to create a data task (not a download task), named dataTask, with a completion handler that returns the results of the data task. Add this data task between the commented section. Once that's done, within the body of the data task, return the results to the fetchTreehouseBlogPosts method's completion handler.

my code

import Foundation

// Add your code below typealias BlogPostCompletion = ((NSData!, NSURLResponse!, NSError!) -> Void)

// Add your code below func fetchTreehouseBlogPosts (completion: BlogPostCompletion) { let blogURL = NSURL(string: "http://blog.teamtreehouse.com/api/") let requestURL = NSURL(string: "get_recent_summary/?count=20", relativeToURL: blogURL)

let request = NSURLRequest(URL: requestURL!)

let config = NSURLSessionConfiguration.defaultSessionConfiguration() let session = NSURLSession(configuration: config)

// Add your code between the comments let dataTask = session.dataTaskWithRequest(request){ (let data, let response, let error) in // Steps. 1 Check HTTP respnose for succesful get request. You can add diferent logic for diferent status codes, but we only did one- the succesful one. if let httpRespnose = response as? NSHTTPURLResponse{

            switch (httpRespnose.statusCode){
            case 200:
                // 2.  create JSON object with data
                let jsonDictionary = NSJSONSerialization.JSONObjectWithData(data, options: nil , error: nil) as? [String:AnyObject]
                completion(jsonDictionary)
            default:
                println("GET Request not succesful. The HTTP Status code is \(httpRespnose.statusCode)")
            }

        } else {println("error not a valid HTTP response ")}


    }

// Add code above

dataTask.resume() }

The error I get:

swift_lint.swift:28:32: error: missing argument for parameter #2 in call completion(jsonDictionary) ^

Help please

Mobify CST
Mobify CST
Courses Plus Student 3,841 Points

Look, your BlogPostCompletion accepts 3 parameters: data, response and error. Conveniently this is exactly what you have in the closure. So you can literally do what your task asks you to do: add the data task and return the results to the completion handler:

 let dataTask = session.dataTaskWithRequest(request) {
 (let data, let response, let error) in    
      completion(data, response, error)
  }

3 Answers

Bruna Aleixo
Bruna Aleixo
2,693 Points
Bruna Aleixo
Bruna Aleixo
2,693 Points 
import Foundation

// Add your code below
typealias BlogPostCompletion = ((NSData!, NSURLResponse!, NSError!) -> Void)
func fetchTreehouseBlogPosts(completion: BlogPostCompletion) {
let blogURL = NSURL(string: "http://blog.teamtreehouse.com/api/")
  let requestURL = NSURL(string: "get_recent_summary/?count=20", relativeToURL: blogURL)

  let request = NSURLRequest(URL: requestURL!)

  let config = NSURLSessionConfiguration.defaultSessionConfiguration()
  let session = NSURLSession(configuration: config)

  let dataTask: NSURLSessionDataTask  = session.dataTaskWithURL(request) {
      (let data, let response, let error) in
      completion(data, response, error)
  }

  dataTask.resume()
}

Why isnt my code working??

Unsubscribed User
Unsubscribed User
Courses Plus Student 22,129 Points

Bruna Aleixo,

The reason why your code is not working is because your dataTask is calling a session with a "dataTaskWithURL". to fix this problem simply change:

session.dataTaskWithURL(request)
// To
session.dataTaskWithRequest(request)

Your Final code should look as follows:

import Foundation

// Add your code below
typealias BlogPostCompletion = ((NSData!, NSURLResponse!, NSError!) -> Void)
func fetchTreehouseBlogPosts(completion: BlogPostCompletion) {
let blogURL = NSURL(string: "http://blog.teamtreehouse.com/api/")
  let requestURL = NSURL(string: "get_recent_summary/?count=20", relativeToURL: blogURL)

  let request = NSURLRequest(URL: requestURL!)

  let config = NSURLSessionConfiguration.defaultSessionConfiguration()
  let session = NSURLSession(configuration: config)

  let dataTask: NSURLSessionDataTask  = session.dataTaskWithRequest(request) {
      (let data, let response, let error) in
      completion(data, response, error)
  }

  dataTask.resume()
}
Kevin Gonzales
Kevin Gonzales
4,638 Points
Kevin Gonzales
Kevin Gonzales
4,638 Points

I think I did it wrong. us in my completion has 3 parameters ?

thomascawthorn
thomascawthorn
22,986 Points
thomascawthorn
thomascawthorn
22,986 Points

I'm only just starting on completions right now! I'll let you know if I can help out afterwards ;)

Kevin Gonzales
Kevin Gonzales
4,638 Points

Thanks!