Refactor

Author: kudoleh

ExampleMVVM/Presentation/MoviesScene/MoviesList/View/MoviesListTableView/MoviesListTableViewController.swift

@@ -11,27 +11,24 @@ final class MoviesListTableViewController: UITableViewController {
 
     var posterImagesRepository: PosterImagesRepository?
     var nextPageLoadingSpinner: UIActivityIndicatorView?
-    
+
     var viewModel: MoviesListViewModel!
-    var items: [MoviesListItemViewModel] = [] {
-        didSet { reload() }
-    }
-    
+
     override func viewDidLoad() {
         super.viewDidLoad()
         tableView.estimatedRowHeight = MoviesListItemCell.height
         tableView.rowHeight = UITableView.automaticDimension
         bind(to: viewModel)
     }
-    
+
     private func bind(to viewModel: MoviesListViewModel) {
         viewModel.loadingType.observe(on: self) { [weak self] in self?.update(isLoadingNextPage: $0 == .nextPage) }
     }
-    
+
     func reload() {
         tableView.reloadData()
     }
-    
+
     func update(isLoadingNextPage: Bool) {
         if isLoadingNextPage {
             nextPageLoadingSpinner?.removeFromSuperview()
@@ -48,31 +45,30 @@ final class MoviesListTableViewController: UITableViewController {
 
 // MARK: - UITableViewDataSource, UITableViewDelegate
 extension MoviesListTableViewController {
-    
+
     override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        return items.count
+        return viewModel.items.value.count
     }
-    
+
     override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
         guard let cell = tableView.dequeueReusableCell(withIdentifier: MoviesListItemCell.reuseIdentifier, for: indexPath) as? MoviesListItemCell else {
-            assertionFailure("Cannot dequeue reusable cell \(MoviesListItemCell.self) with reuseIdentifier: \(MoviesListItemCell.reuseIdentifier)")
-            return .init()
+            fatalError("Cannot dequeue reusable cell \(MoviesListItemCell.self) with reuseIdentifier: \(MoviesListItemCell.reuseIdentifier)")
         }
 
-        cell.fill(with: items[indexPath.row],
+        cell.fill(with: viewModel.items.value[indexPath.row],
                   posterImagesRepository: posterImagesRepository)
 
-        if indexPath.row == items.count - 1 {
+        if indexPath.row == viewModel.items.value.count - 1 {
             viewModel.didLoadNextPage()
         }
-        
+
         return cell
     }
-    
+
     override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
         return viewModel.isEmpty ? tableView.frame.height : super.tableView(tableView, heightForRowAt: indexPath)
     }
-    
+
     override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
         viewModel.didSelectItem(at: indexPath.row)
     }

ExampleMVVM/Presentation/MoviesScene/MoviesList/View/MoviesListViewController.swift

@@ -45,7 +45,7 @@ final class MoviesListViewController: UIViewController, StoryboardInstantiable,
     }
 
     private func bind(to viewModel: MoviesListViewModel) {
-        viewModel.items.observe(on: self) { [weak self] in self?.moviesTableViewController?.items = $0 }
+        viewModel.items.observe(on: self) { [weak self] _ in self?.moviesTableViewController?.reload() }
         viewModel.query.observe(on: self) { [weak self] in self?.updateSearchController(query: $0) }
         viewModel.error.observe(on: self) { [weak self] in self?.showError($0) }
         viewModel.loadingType.observe(on: self) { [weak self] _ in self?.updateViewsVisibility() }

ExampleMVVM/Presentation/MoviesScene/MoviesList/ViewModel/MoviesListViewModel.swift

@@ -58,7 +58,7 @@ final class DefaultMoviesListViewModel: MoviesListViewModel {
         let moviesPage: MoviesPage
         let items: [MoviesListItemViewModel]
     }
-    private var pages: [Page] = []
+    private var pages: [MoviesPage] = []
     private var moviesLoadTask: Cancellable? { willSet { moviesLoadTask?.cancel() } }
 
     // MARK: - OUTPUT
@@ -88,11 +88,10 @@ final class DefaultMoviesListViewModel: MoviesListViewModel {
         totalPageCount = moviesPage.totalPages
 
         pages = pages
-            .filter { $0.moviesPage.page != moviesPage.page }
-            + [Page(moviesPage: moviesPage,
-                    items: moviesPage.movies.map(MoviesListItemViewModel.init))]
+            .filter { $0.page != moviesPage.page }
+            + [moviesPage]
 
-        items.value = pages.items
+        items.value = pages.movies.map(MoviesListItemViewModel.init)
     }
 
     private func resetPages() {
@@ -168,7 +167,6 @@ extension DefaultMoviesListViewModel {
 
 // MARK: - Private
 
-private extension Array where Element == DefaultMoviesListViewModel.Page {
-    var movies: [Movie] { flatMap { $0.moviesPage.movies } }
-    var items: [MoviesListItemViewModel] { flatMap { $0.items } }
+private extension Array where Element == MoviesPage {
+    var movies: [Movie] { flatMap { $0.movies } }
 }

ExampleMVVM/Presentation/Utils/Observable.swift

@@ -26,7 +26,7 @@ public final class Observable<Value> {
 
     public func observe(on observer: AnyObject, observerBlock: @escaping (Value) -> Void) {
         observers.append(Observer(observer: observer, block: observerBlock))
-        DispatchQueue.main.async { observerBlock(self.value) }
+        observerBlock(self.value)
     }
 
     public func remove(observer: AnyObject) {