Rx DataSource custom implementation example.

ViewController.swift

//
// Created by Daniel Tartaglia on 4/20/17.
// Copyright © 2017 Daniel Tartaglia. MIT License.


import UIKit
import RxSwift
import RxCocoa

class ViewController: UIViewController {

    @IBOutlet weak var tableView: UITableView!

    override func viewDidLoad() {
        super.viewDidLoad()

        let items = Observable.just(["1", "2", "3"])

        items.bind(to: tableView.rx.items(dataSource: DataSource()))
            .disposed(by: bag)
    }

    private let bag = DisposeBag()
}

class DataSource: NSObject, RxTableViewDataSourceType, UITableViewDataSource {

    typealias Element = [String]

    func tableView(_ tableView: UITableView, observedEvent event: Event<[String]>) {
        if case let .next(items) = event {
            self.items = items
            tableView.reloadData()
        }
    }

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

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
        cell.textLabel?.text = items[indexPath.row]
        return cell
    }

    func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        return "Header"
    }

    private var items: Element = []
}