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iOS Build a Weather App with Swift (Retired) Pulling Data From the Web Fetching JSON Data

Posted by beven nyamande
beven nyamande
9,575 Points

ios networking

i have assigned the constant "courseData" but am still getting an error where am i going wrong?

students_code.swift 
import Foundation
let treehouseBaseURL = NSURL(string: "https://api.teamtreehouse.com/")
let courseURL = NSURL(string: "/course/\(courseID)", relativeToURL: treehouseBaseURL)

let courseData =NSData.dataWithContentsOfURL(courseURL ,options: nil ,error : nil)

1 Answer

Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

the method you are calling is no longer used in Xcode 6.1. the challenge has been updated to reflect that. see the teachers notes of this video for more information:

from the notes:

This course uses Xcode 6.0.1 and since its release, Xcode has been updated to Xcode 6.1. In the process some changes have been made to the APIs we work with in this course and in this particular video, the use of the NSData class initializer has been modified from

NSData.dataWithContentsOfURL(url: NSURL, options: NSDataReadingOptions, error: NSErrorPointer)

to

NSData(contentsOfURL: NSURL, options: NSDataReadingOptions, error: NSErrorPointer)

Additionally, the NSURL constructor now returns an optional so when you pass the url to the NSData method, it needs to be unwrapped.

looking at the NSData class reference, we can see that it has an init method that looks like this:

init?(contentsOfURL aURL: NSURL,
            options mask: NSDataReadingOptions,
              error errorPtr: NSErrorPointer)

its an init method which means you call it like so:

NSData(contentsOfURL: aURL,
            options: someOptions,
              error: someError)

note that the NSURL initializer returns an optional, so you will need to force unwrap courseURL using !

import Foundation
let treehouseBaseURL = NSURL(string: "https://api.teamtreehouse.com/")
let courseURL = NSURL(string: "/course/\(courseID)", relativeToURL: treehouseBaseURL)
let courseData  = NSData(contentsOfURL: courseURL!, options: nil , error: nil)