how to fix tableview automatic height in swift?

Question

I want to display vertical data collection view in table view cell. but when the data is first reloaded from json the height of the table view doesn't change automatically. but when the tableview is scrolled up, the height of the tableview changes as shown below

1. This first image appeared when reloading data from Json: enter image description here

2. this image when tableview is scrolled up enter image description here

here is myCode:

• view controller

  import UIKit
  
  class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, reloadTable {
  
    func reloadTableData() {
      self.tableView.reloadData()
      self.tableView.beginUpdates()
      self.tableView.endUpdates()
    }
  
  @IBOutlet var tableView: UITableView!
  
  override func viewDidLoad() {
  super.viewDidLoad()
  // Do any additional setup after loading the view, typically from a nib.
  tableView.register(UINib(nibName: "TableViewCell", bundle: nil), forCellReuseIdentifier: Cell.tableView.rawValue)
  tableView.rowHeight = UITableView.automaticDimension
  tableView.estimatedRowHeight = 100
  tableView.tableFooterView = UIView()
  
  tableView.register(UINib(nibName: "SecondTableViewCell", bundle: nil), forCellReuseIdentifier: "SecondTableViewCell")
  
  }
  
  func numberOfSections(in tableView: UITableView) -> Int {
      return 1
  }
  
  func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
       return 2
  }
  
   func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
  if indexPath.row == 0{
  
      let cell = tableView.dequeueReusableCell(withIdentifier: "SecondTableViewCell", for: indexPath) as! SecondTableViewCell
      cell.name.text = "first data"
      return cell
  
  }else{
  
      let cell = tableView.dequeueReusableCell(withIdentifier: Cell.tableView.rawValue, for: indexPath) as! TableViewCell
      cell.setNeedsLayout()
      cell.layoutIfNeeded()
      return cell
    }
  }
  
  func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
     if indexPath.row == 0{
        return 100
     }else {
        return UITableView.automaticDimension
     }
    }
   }
  

here is my tableview cell:

• TableViewCell

  import UIKit
  import Alamofire
  import SwiftyJSON
  
  struct dataJSON {
     var name: String
  }
  
  protocol reloadTable {
   func reloadTableData()
  }
  
  class TableViewCell: UITableViewCell, UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout{
  
  
  var reload: reloadTable?
  
  var dataJson : [dataJSON] = []
  
  @IBOutlet var collectionView: UICollectionView!
  
  override func awakeFromNib() {
    super.awakeFromNib()
  
    fetchData()
  
    collectionView.delegate = self
    collectionView.dataSource = self
    collectionView.isScrollEnabled = false
    collectionView.register(UINib(nibName: "CollectionViewCell", bundle: nil), forCellWithReuseIdentifier: Cell.collView.rawValue)
  
    let collViewLayout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
    collViewLayout.itemSize = UICollectionViewFlowLayout.automaticSize
    layoutIfNeeded()
    setNeedsLayout()
  
    }
  
    func numberOfSections(in collectionView: UICollectionView) -> Int {
      return 1
   }
  
    func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
      return dataJson.count
   }
  
    func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
       let cell = collectionView.dequeueReusableCell(withReuseIdentifier: Cell.collView.rawValue, for: indexPath) as! CollectionViewCell
       cell.detail.text = dataJson[indexPath.row].name
       return cell
   }
  
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
       return CGSize(width: collectionView.frame.size.width / 2 - 10, height:  300)
   }
  
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
       return 5
   }
  
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
      return 5
   }
  
    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
      return UIEdgeInsets(top: 3, left: 3, bottom: 3, right: 3)
    }
  
    func fetchData(){
     Alamofire.request("https://jsonplaceholder.typicode.com/users", method: .get, parameters: nil, encoding: URLEncoding.default, headers: nil).responseJSON{
      (response) in
  
      switch response.result{
          case .success(let value):
              print(value)
              let json = JSON(value)
  
              let name = json["name"].stringValue
              print("nameesss: \(name)")
  
              json.array?.forEach({ (item) in
                  let data = item["name"].stringValue
                  self.dataJson.append(dataJSON(name: data))
              })
  
              self.collectionView.reloadData()
              self.reload?.reloadTableData()
  
          case .failure(let error):
              print(error)
      }
    }
  }
  
  override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize {
     self.collectionView.frame = CGRect(x: 0, y: 0, width: targetSize.width, height: 600)
     self.collectionView.layoutIfNeeded()
     return self.collectionView.collectionViewLayout.collectionViewContentSize
      }
    }
  

Answer 1

Try with

 DispatchQueue.main.async { [weak self] in
        self?.tableView.reloadData()
    }

Answer 2

After inserting data you must update subviews with self.view.layoutSubviews().

Answer 3

Make the delegate and datasource connections from the connection inspector. Click and drag the outlets from connection inspector to File owner for datasource and delegate.