CODEWITHSUNDEEP
swift
Jon Sakas
Jon Sakas

Reputation: 2232

Simple network request with Swift 4

I'm currently learning swift coming from a web development background and I am a little stuck making a simple network request.

I'm using the document below to learn about URLSession and dataTask, but I seems a have a conceptual misunderstanding of how the documentation is using with. (Any explanation there would be appreciated)

https://developer.apple.com/documentation/foundation/urlsession/1410330-datatask

Here is my code:

import Foundation

let url = URL(string: "https://swapi.co/api/people/1/")
let urlSession = URLSession.shared


func completionHandler (_ data : Data?, _ response : URLResponse?, _ error : Error?) -> Void {
    print("Completed.")
}

urlSession.dataTask(with url : url, completionHandler : completionHandler)

The error: 

Playground execution failed:

error: MyPlayground.playground:5:26: error: expected ',' separator
urlSession.dataTask(with url : url, completionHandler : completionHandler)
                         ^
                        ,

Xcode version 9.2

Swift version 4.0.3 (swiftlang-900.0.74.1 clang-900.0.39.2)

Upvotes: 0

Views: 254

Answers (1)

vikingosegundo
vikingosegundo

Reputation: 52227

try 

urlSession.dataTask(with: url!, completionHandler: completionHandler)

note that you force unwrap url here. better use guard let or if let to avoid it.

if let url = URL(string: "https://swapi.co/api/people/1/") {
    let urlSession = URLSession.shared

    let completionHandler: (_ data: Data?, _ response: URLResponse?, _ error: Error?) -> Void  = { _,_,_ in
        print("Completed.")
    }

    let task = urlSession.dataTask(with: url, completionHandler: completionHandler)
    task.resume()
}

In playgrounds you also need to activate indefinite execution

import PlaygroundSupport

import Foundation

if let url = URL(string: "https://swapi.co/api/people/1/") {
    let urlSession = URLSession.shared

    let completionHandler: (_ data: Data?, _ response: URLResponse?, _ error: Error?) -> Void  = { _,_,_ in
        print("Completed.")
    }

    let task = urlSession.dataTask(with: url, completionHandler: completionHandler)
    task.resume()
}

PlaygroundPage.current.needsIndefiniteExecution = true

Upvotes: 2

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