Populating UITableView from JSON - swift4

Question

I'm trying to use a JSON file to populate a UITableView in my app. Previously I was hard coding an array of sample data, but need to move to using my JSON file. This is a mishmash of various tutorials and answers found on SO, so I apologize if the syntax conventions are a little off.
import UIKit
import os.log
class BonusTableViewController: UITableViewController {
//MARK: Properties
var bonuses = [Bonus]() // Used for old sample data
var jBonuses = [Bonuses]() // Used with JSON based data
override func viewDidLoad() {
super.viewDidLoad()
//MARK: Confirm JSON file was loaded and log the Bonus Codes
let loadedBonuses = loadJson(filename: "BonusData")
for bonus in loadedBonuses! {
print(bonus.bonusCode)
}
}
// Load the JSON file from the bundled file.
func loadJson(filename fileName: String) -> [Bonuses]? {
if let url = Bundle.main.url(forResource: fileName, withExtension: "json") {
do {
let data = try Data(contentsOf: url)
let decoder = JSONDecoder()
let jsonData = try decoder.decode(JSONData.self, from: data)
print("loadJson loaded JSON")
return jsonData.bonuses
} catch {
print("error:\(error)")
}
}
return nil
}
// MARK: Data Structures
// Bonus Data Structs
struct JSONData: Decodable {
let name: String
let version: String
let bonuses: [Bonuses]
}
struct Bonuses: Decodable {
let bonusCode: String
let category: String
let name: String
let value: Int
let city: String
let state: String
let flavor: String
let imageData: String
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return jBonuses.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// Table view cells are reused and should be dequeued using a cell identifier.
let cellIdentifier = "BonusTableViewCell"
guard let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as? BonusTableViewCell else {
fatalError("The dequeued cell is not an instance of BonusTableViewCell.")
}
// Now using JSON file
let jBonus = jBonuses[indexPath.row]
print("Setting labels using JSON file")
cell.bonusCodeLabel.text = jBonus.bonusCode
cell.categoryLabel.text = jBonus.category
cell.nameLabel.text = jBonus.name
cell.valueLabel.text = "\(jBonus.value)"
cell.cityLabel.text = "\(jBonus.city),"
cell.stateLabel.text = jBonus.state
cell.flavorText.text = jBonus.flavor
cell.primaryImage.image = jBonus.photo
return cell
}
From the console, I can confirm that it is able to see the JSON data and it does spit out the list of bonus codes. I can't pinpoint why this isn't working, but the result is a blank just a tableview with a bunch of empty rows.

Answer 1

Replace viewDidLoad with
override func viewDidLoad() {
super.viewDidLoad()
jBonuses = loadJson(filename: "BonusData")!
tableView.reloadData()
}
You have to assign the loaded data to the data source array and reload the table view.
Or if loadedBonuses could really be nil (it cannot in this case):
override func viewDidLoad() {
super.viewDidLoad()
if let loadedBonuses = loadJson(filename: "BonusData") {
jBonuses = loadedBonuses
tableView.reloadData()
}
}
Notes:
Delete the method numberOfSections, 1 is the default.
Force unwrap the cell, the code must not crash if everything is hooked up properly
let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as! BonusTableViewCell

Answer 2

You are populating Tableview using jBonuses array of Type Bonuses, but where you are filling the jBonuses array.
It seems that you are not filling jBonuses Array. Fill the jBonuses array once you get API response and call tableview reloadData method.
yourTableView.reloadData()