HTTP Requests in Swift 3

Question

I am fairly new to Swift, and am trying to make an HTTP request. I tried many of the ideas in this Stack Overflow question, but all caused errors when run in a playground; I believe this is because they are all in Swift 1.0-2.0.

How can I make an HTTP request in Swift 3?

Update I tried the first solution presented in this answer and, after completing Xcode's suggested "Fix-its" I encountered four errors:

when working with playground you need to wait for http response with XCPlaygroundPage.currentPage.needsIndefiniteExecution = true — Ali Kıran, Jul 10 '16 at 14:16
it's just hint for testing asynchronous code in playground.And also if you provide what kind of errors encountering in question we will help you more. — Ali Kıran, Jul 10 '16 at 14:22
@AliKiran I updated my question with what errors I encountered. — owlswipe, Jul 10 '16 at 14:26
Thanks for solving this everyone! Each one of the three answers below works great. — owlswipe, Jan 18 '17 at 17:25

score 40 · Accepted Answer · edited Feb 18 '17 at 23:42

There are a couple problems with your code:

By default, your app cannot connect to insecure (i.e. HTTP) site. It's a feature called App Transport Security. You need to make an exception in your app's Info.plist file to connect to HTTP sites.
This: dataTask(urlwith: ! as URL). What are you trying to unwrap with the exclamation mark (!)? What's the variable name?

A lot of class names have changed between Swift 2 and 3 so those answers you've found may not be applicable. Below is an example that connects to httpbin.org to get your IP address:

import PlaygroundSupport
import Foundation

let url = URL(string: "https://httpbin.org/ip")

let task = URLSession.shared.dataTask(with: url!) { data, response, error in
    guard error == nil else {
        print(error!)
        return
    }
    guard let data = data else {
        print("Data is empty")
        return
    }

    let json = try! JSONSerialization.jsonObject(with: data, options: [])
    print(json)
}

task.resume()
PlaygroundPage.current.needsIndefiniteExecution = true

Love it! Perfect, and thanks for the tips (I did know the first one, and for the second one the weird exclamation point came from Xcode doing a bunch of weird fix-its including that one)! — owlswipe, Jul 10 '16 at 15:48

Eric Aya · Answer 2 · 2016-07-10T15:52:31.530

14

There's typo errors (no url variable in the call) in your code.

Anyway, in Swift 3 it's better to use the new URL struct and the URLSession class.

Also, XCPlayground is now PlaygroundSupport.

And no need to use NSString when String is available.

import PlaygroundSupport
PlaygroundPage.current.needsIndefiniteExecution = true

let url = URL(string: "http://stackoverflow.com/")
let task = URLSession.shared.dataTask(with: url!) { (data, response, error) in
    if let data = data,
        html = String(data: data, encoding: String.Encoding.utf8) {
            print(html)
    }
}
task.resume()

Note: this is for Xcode 8 beta 2. On beta 1 you would have to do shared() instead of shared. If you're on iOS don't forget to import UIKit, but this code also works for OS X if you import Cocoa instead.

edited Jul 10 '16 at 15:52

answered Jul 10 '16 at 14:43

Eric Aya

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Thanks! This totally works for me, but I can't accept it until you fix the two errors in the code: you'll need to add a () after `shared` on line 5 and add import UIKit to the beginning, even if that seems self-explanatory. – owlswipe Jul 10 '16 at 15:46
Got it! Thanks for your help. – owlswipe Jul 10 '16 at 15:52
Sorry, I would have accepted just Code Different was first...your answer is just as good! Somebody upvote this. – owlswipe Jul 10 '16 at 16:01
Eh, no problem. The accepted answer is ok - and you're free to choose the one you want anyway. Thanks! :) – Eric Aya Jul 10 '16 at 16:03

Ali Kıran · Answer 3 · 2016-07-10T16:14:39.327

In your error it seems url missing.Here bare simple api call to help you get started with.

import UIKit
import Foundation
import PlaygroundSupport

let url:URL = URL(string: "http://jsonplaceholder.typicode.com/posts")!
let session = URLSession.shared

var request = URLRequest(url: url)
request.httpMethod = "POST"
request.cachePolicy = NSURLRequest.CachePolicy.reloadIgnoringCacheData

let paramString = "data=Hello"
request.httpBody = paramString.data(using: String.Encoding.utf8)

let task = session.dataTask(with: request as URLRequest) {
    (
    data, response, error) in

    guard let data = data, let _:URLResponse = response  where error == nil else {
        print("error")
        return
    }

    let dataString =  String(data: data, encoding: String.Encoding.utf8)
    print(dataString)

}

task.resume()

PlaygroundPage.current.needsIndefiniteExecution = true

Thank you! This code sample works great, it's just that I don't think my mistake was not including a URL. — owlswipe, Jul 10 '16 at 15:49
@Rob thank you for code review i update my sample according to your feedback.By the way printing NSString give formatted output.But it doesn't make much sense — Ali Kıran, Jul 10 '16 at 16:15

HTTP Requests in Swift 3

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