Parsing Json to UITableview

Question

I have a UITableView and I need to populate with cells using data from some JSON that I get online. I have successfully acquired and parsed the data. The issue lies in the cells not being created with the proper data because they are created before the JSON Finishes loading and therefore cannot be displayed with the data. I know that you can easily use tableView.reloadData() and I run into another issue. I need to get the data downloaded before I even call any of the tableView methods.

The reason for this is because I want to return the number of cells based on how many cells are in the JSON. so something like jsoncells.count

This is my code so far: I had versions that kinda worked but they're gone since I've been tinkering with the code a little bit.

import UIKit

class TimelineViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {

@IBOutlet weak var backgroundImageView: UIImageView!
var timelineCellDataArray = [[String:String]]()
override func viewDidLoad() {
    super.viewDidLoad()
    setupBackground(backgroundImage: #imageLiteral(resourceName: "Placeholder 1.jpeg"))
}

func setupBackground(backgroundImage: UIImage) {
    backgroundImageView.image = backgroundImage

    // Background Image Blur Effect:
    let backgroundImageBlurEffect = UIBlurEffect(style: .light)
    let backgroundImageBlurEffectView = UIVisualEffectView(effect: backgroundImageBlurEffect)
    backgroundImageBlurEffectView.frame = backgroundImageView.frame
    backgroundImageView.addSubview(backgroundImageBlurEffectView)
}

// Change View Controller To Profle View Controller
func setViewToProfileViewController() {
    print("H")
    let storyboard = UIStoryboard(name: "Main", bundle: nil)
    let vc = storyboard.instantiateViewController(withIdentifier: "ProfileViewController") as! ProfileViewController
    self.navigationController?.pushViewController(vc, animated: true)
}



func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 4
}

var isLoad = true
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    var cell = tableView.dequeueReusableCell(withIdentifier: "TimelineCell", for: indexPath) as! TimelineCell

    // Json Parsing For Cell Populating
    let urlString = "https://www.jasonbase.com/things/QRkQ.json"
    let url = URL(string: urlString)
        URLSession.shared.dataTask(with: url!) { (data, response, error) in
            if error != nil  {

            } else {
                do {
                    let parsedData = try JSONSerialization.jsonObject(with: data!) as! [String:[[String:String]]]
                    self.timelineCellDataArray = parsedData["timelineCell"]!
                    DispatchQueue.main.async {
                        print("we")
                        switch self.timelineCellDataArray[indexPath.row]["cellType"] {
                        case "1"?:
                            cell = cell.createPostCell(cellToUse: cell)
                        case "2"?:
                            cell = cell.createPartyCell(cellToUse: cell)
                        case"3"?:
                            cell = cell.createFriendRequestCell(cellToUse: cell)
                        default:
                            break
                        }
                        tableView.reloadData()
                        self.isLoad = false
                    }
                } catch let error as NSError {
                    print(error)
                }
            }
            }.resume()
    print("WD")
    return cell
}

}

Here is my JSON https://www.jasonbase.com/things/QRkQ.json

Answer 1

Do your JSON acquisition in viewDidLoad. You can then create a global variable (it seems you are using the variable called timelineCellDataArray) that stores your data that you append to every time you get new data from your database.

Once you finish getting all your data from the database, you call tableView.reloadData(). That way in your numberOfRowsInSection function, you can just return timelineCellDataArray.count. In your cellForRowAt function, you can just take the object in timelineCellDataArray[index.row] and populate your cell with this data.