Connecting JSON from external server to Swift tableView

Question

I am new to Swift, and am trying to create a table that reads JSON data from my website. I followed some tutorials, and was able to get my code to work with a table controller. Now I'm trying to use a view controller with a table view inside, so I can have more customization. My problem is, I can't get the data to actually show up when I try to use my new code.

This is what I have in my viewController.swift:

import UIKit

class ViewController: UIViewController {

@IBOutlet weak var tableView: UITableView!
var TableData:Array< String > = Array < String >()


override func viewDidLoad() {
    super.viewDidLoad()

    get_data_from_url("http://www.stevenbunting.org/Alliris/service.php")
}



func numberOfSections(in tableView: UITableView) -> Int {
    return 1
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return TableData.count
}


func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)

    cell.textLabel?.text = TableData[indexPath.row]

    return cell
}






func get_data_from_url(_ link:String)
{
    let url:URL = URL(string: link)!
    let session = URLSession.shared

    let request = NSMutableURLRequest(url: url)
    request.httpMethod = "GET"
    request.cachePolicy = NSURLRequest.CachePolicy.reloadIgnoringCacheData


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

        guard let _:Data = data, let _:URLResponse = response  , error == nil else {

            return
        }


        self.extract_json(data!)


    })

    task.resume()

}


func extract_json(_ data: Data)
{


    let json: Any?

    do
    {
        json = try JSONSerialization.jsonObject(with: data, options: [])
    }
    catch
    {
        return
    }

    guard let data_list = json as? NSArray else
    {
        return
    }


    if let countries_list = json as? NSArray
    {
        for i in 0 ..< data_list.count
        {
            if let country_obj = countries_list[i] as? NSDictionary
            {
                if let country_name = country_obj["user"] as? String
                {
                    if let country_code = country_obj["friendlist"] as? String
                    {
                        TableData.append(country_name + " [" + country_code + "]")
                    }
                }
            }
        }
    }



    DispatchQueue.main.async(execute: {self.do_table_refresh()

    })

}

func do_table_refresh()
{
    self.tableView.reloadData()

}


}

Have you set the ViewController as the tableView's datasource? Probably not, as your ViewController-code doesn't implement the [UITableViewDataSource-protocol](https://developer.apple.com/reference/uikit/uitableviewdatasource) ;) — Nathan Mattes, Mar 16 '17 at 20:16

score 0 · Accepted Answer · edited May 23 '17 at 11:46

Probably you didn't set the tableView's dataSource. To do this, implement the UITableViewDataSource-protocol in the ViewController-class and set the tableView's dataSource-property to self in the viewDidLoad(), for example:

class ViewController: UIViewController, UITableViewDataSource {
// ...
    override func viewDidLoad() {
        super.viewDidLoad()

        tableView.dataSource = self
        // ...
    } 
    //...
}

Oh, and don't forget about the Apple Transport Security-settings, otherwise you won't see anything as iOS doesn't allow HTTP anymore, you have use HTTPS. The right way to handle this is to get an SSL-Certificate for your domain.

The quick'n'dirty and absolutely not recommended way is to disable ATS or to set an exception for certain, trustworthy domains.

Connecting JSON from external server to Swift tableView

1 Answers1