Quick Playground for adding rows to the top of a tableview

Playground.swift

import PlaygroundSupport
import UIKit

class TableViewManager: NSObject, UITableViewDataSource, UITableViewDelegate {
    
    weak var tableView: UITableView?
    
    var strings = ["a", "b", "c", "d","e", "f", "g", "h","i", "j", "k", "dl","am", "bn", "co", "dp","aq", "br", "cs", "dt","au", "bv", "cw", "dx","ay", "bz", "caa", "dbb","acc", "bdd", "cee", "dff","agg", "bhh", "cii", "djj","akk", "bll", "cmm", "dnn","aoo", "bpp", "cqq", "zrr"]
    
    func add(data: [String]) {
        strings.insert(contentsOf: data, at: 0) // add your data to the top of source
//        updateWithScroll(data: data)
        updateWithContentOffsset(data: data)
    }
    
    func updateWithScroll(data: [String]) {
        guard let tableView = tableView else {
            return
        }
        guard let currentVisibleIndexPaths = tableView.indexPathsForVisibleRows else {
            return
        }
        var updatedVisibleIndexPaths = [IndexPath]()
        for indexPath in currentVisibleIndexPaths {
            let newIndexPath = IndexPath(row: indexPath.row + data.count, section: indexPath.section)
            updatedVisibleIndexPaths.append(newIndexPath)
        }
        
        tableView.reloadData()
        tableView.scrollToRow(at: updatedVisibleIndexPaths[0], at: .top, animated: false)
    }
    
    // Will probably get extremely complicated with dynamic cell height
    func updateWithContentOffsset(data: [String]) {
        guard let tableView = tableView else {
            return
        }
        let currentOffset = tableView.contentOffset
        let yOffset = CGFloat(data.count) * tableView.rowHeight // MAKE SURE YOU SET THE ROW HEIGHT OTHERWISE IT WILL BE ZERO!!!
        let newOffset = CGPoint(x: currentOffset.x, y: currentOffset.y + yOffset)
        tableView.reloadData()
        tableView.setContentOffset(newOffset, animated: false)
    }
    
    func numberOfSections(in tableView: UITableView) -> Int {
        return 1
    }
    
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return strings.count
    }
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! Cell
        cell.textLabel?.text = strings[indexPath.row]
        cell.backgroundColor = .green
        return cell
    }
    
    func scrollViewDidScroll(_ scrollView: UIScrollView) {
        print(scrollView.contentOffset.y)
    }
}


class Cell: UITableViewCell {
    
}

let view = UIView(frame: CGRect(x: 0, y: 0, width: 375, height: 667))
view.backgroundColor = .blue

let tableView = UITableView(frame: view.bounds)
view.addSubview(tableView)

tableView.register(Cell.self, forCellReuseIdentifier: "cell")

let tableManager = TableViewManager()
tableManager.tableView = tableView
tableView.dataSource = tableManager
tableView.delegate = tableManager
tableView.rowHeight = 44

let deadlineTime = DispatchTime.now() + .seconds(5)
DispatchQueue.main.asyncAfter(deadline: deadlineTime, execute: {
    tableManager.add(data: ["m","j","k"])
    print("added data")
})

PlaygroundPage.current.liveView = view
PlaygroundPage.current.needsIndefiniteExecution = true