Swift 4中的可编码JSON字典

Question

With the help of @matt. I was able to solve it and the finished code is below for anyone who will encounter similer issues in the near future. Given the below JSON

{
    "restaurants": [
        {
            "id": 1,
            "restaurantName": "Chuks",
            "restaurantPicture": "restaurantImages/benards.jpg",
            "status": "Working",
            "workingDays": "Tuesday to Sunday",
            "workingHours": "3pm to 10pm"
        },
        {
            "id": 3,
            "restaurantName": "Chuks",
            "restaurantPicture": "restaurantImages/benards.jpg",
            "status": "Working",
            "workingDays": "Tuesday to Sunday",
            "workingHours": "3pm to 10pm"
        },
        {
            "id": 4,
            "restaurantName": "Chuks",
            "restaurantPicture": "restaurantImages/benards.jpg",
            "status": "Working",
            "workingDays": "Tuesday to Sunday",
            "workingHours": "3pm to 10pm"
        },
        {
            "id": 5,
            "restaurantName": "Chuks",
            "restaurantPicture": "restaurantImages/benards.jpg",
            "status": "Working",
            "workingDays": "Tuesday to Sunday",
            "workingHours": "3pm to 10pm"
        },
        {
            "id": 6,
            "restaurantName": "Chuks",
            "restaurantPicture": "restaurantImages/benards.jpg",
            "status": "Working",
            "workingDays": "Tuesday to Sunday",
            "workingHours": "3pm to 10pm"
        }
    ]
}

And I am trying to access the arrays within the Dictionary with this code into a table. So I have made a Struct. Below is the content of my Structfile.

    struct Response: Codable {

    let restaurants: [Restaurant]

    struct Restaurant: Codable {
        let id: Int
        let restaurantName: String
        let restaurantPicture: String
        let status: String
        let workingDays: String
        let workingHours: String
    }
}

This is my main View Controller

        import UIKit

    class ViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {


        @IBOutlet weak var tabelView: UITableView!

        var restaurants = [Response]()

        override func viewDidLoad() {
            super.viewDidLoad()
            // Do any additional setup after loading the view, typically from a nib.

            downloadJSON {
                self.tabelView.reloadData()
            }

            tabelView.delegate = self
            tabelView.dataSource = self

        }

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

        func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
            let cell = UITableViewCell(style: .default, reuseIdentifier: nil)

            cell.textLabel?.text = restaurants[indexPath.row].restaurantName.capitalized

            return cell
        }


        func downloadJSON(completed: @escaping ()->()){

            let url = URL(string: "http://localhost:8888/tableview/tableView.php")

            URLSession.shared.dataTask(with: url!) { (data, response, error) in

                if error == nil{
                    do{
                        let downloadedRestaurants = try JSONDecoder().decode(Response.self, from: data!)
        print(downloadedRestaurants.restaurants.map{$0.restaurantName})

        self.restaurant.append(downloadedRestaurants)


                        DispatchQueue.main.async {
                            completed()
                        }
                    }catch{
                        print(error)
                    }
                }
            }.resume()

        }
    }

Thanks @matt. I hope this piece becomes useful to other newbies or anyone who is having similar issues Cheers!

Answer 1

The problem is that you are trying to decode as [RestaurantStats] . But look at your JSON! It is not an array of RestaurantStats. It is not an array at all. It is a dictionary with a single key, "restaurants" . You need to create that struct and decode as that .

EDIT Since I gave my answer, you have revised your code to declare an outer struct Response. And that's correct — and is exactly what I said you should do. So decode as Response and you're all set.