How to parse jsondata using API in swift 4 - ios

Question

"collection_listings" = (
{
"body_html" = "";
"collection_id" = 57229082710;
"default_product_image" = "<null>";
handle = men;
image = {
"created_at" = "2018-05-02T01:34:16-04:00";
src = "https://cdn.shopify.com/s/files/1/2331/3377/collections/men.jpg?v=1525239256";
};
"published_at" = "2018-05-02T01:34:16-04:00";
"sort_order" = manual;
title = Men;
"updated_at" = "2018-05-02T08:01:58-04:00";
}
How to print this data in the simulator using swift 4?
While I'm trying to print this data, I get this error:
typeMismatch(Swift.Array, Swift.DecodingError.Context(codingPath:
[], debugDescription: "Expected to decode Array but found a
dictionary instead.", underlyingError: nil))
Here is my updated code:
import UIKit
struct product: Decodable
{
let product_id : String
let title : String
let image : String
}
class ViewController: UIViewController,UICollectionViewDataSource
{
var products = product
#IBOutlet weak var productCell: UICollectionView!
override func viewDidLoad()
{
super.viewDidLoad()
productCell.dataSource = self
guard let url = URL(string: "https://psofttech-test.myshopify.com/admin/collection_listings.json") else { return }
var request = URLRequest(url: url)
request.httpMethod = "GET"
let session = URLSession.shared
session.dataTask(with: url) { (data, response, error) in
if error == nil
{
do
{
let json = try JSONSerialization.jsonObject(with: data!) as? [String: Any]
self.products = try JSONDecoder().decode([product].self, from: data!)
print(self.products, "dddd")
for info in self.products
{
self.productCell.reloadData()
}
}
catch
{
print(error)
}
}
}.resume()
print(products.self,"0000")
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int
{
return products.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell
{
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "productCollection", for: indexPath) as! productCollectionViewCell
cell.proLBL.text = products[indexPath.row].title
return cell
}
}

Answer 1

See if this code helps you..
if let data = data as? [String: Any] {
if let data = data["collection_listings"] as? NSArray {
for data in data {
if let data = data as [String: Any] {
}
}
}
}

Answer 2

Now you can use codable to parse json data in Swift 4.0.
Using Codable, we can model JSONObject or PropertyList file into
equivalent Struct or Classes by writing very few lines of code. We
don’t have to write the constructor for the properties in the
objects. It’s all handed by Codable. We just need to extend our model
to conform to the Codable, Decodable or Encodable protocol.
Mismatch between the strong data types of Swift and lose data types
of JSON has been internally handled by Swift compiler. We can now
handle Swift Data types like Date, URL, Float etc
Complex JSON can be modelled easily using Nesting Structs for
readability.
Parsing actual JSON become one-liner using JSONDecoder
You can refer to this app for using the codable : Demo App for Codable Swift

Answer 3

You're using the wrong object to decode. Basically it's telling you that the object type you sent to the decoder does not match the JSON. In your case (without seeing your code it's hard to tell exactly) it seems the object you provided is of type of array, and the JSON is a dictionary. This is the method I typically use:
Specify a struct of the type you want to decode:
struct Response {
var collection_listings: Listing
}
struct Listing {
var collection_id: String
}
In your decoder specific something like:
let decoder = JSONDecoder()
let apiResponse = try decoder.decode(Response.self, from: data)