feat(favorites): adding core data logic to CoreDataClient class

iOSBooks/Podfile

@@ -7,7 +7,6 @@ target 'iOSBooks' do
 
   # Pods for iOSBooks
   pod 'PromiseKit'
-  pod 'IQKeyboardManagerSwift'
   pod 'Kingfisher', "~>5.1"
 
   target 'iOSBooksTests' do

iOSBooks/iOSBooks.xcodeproj/project.pbxproj

@@ -37,6 +37,8 @@
 		74B9185223199E8F00ADDEA4 /* BookDetailViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 74B9185123199E8F00ADDEA4 /* BookDetailViewModel.swift */; };
 		74B9185423199F4500ADDEA4 /* BookDetailViewController+View.swift in Sources */ = {isa = PBXBuildFile; fileRef = 74B9185323199F4500ADDEA4 /* BookDetailViewController+View.swift */; };
 		74B918562319AE0300ADDEA4 /* BookDetailViewController+Safari.swift in Sources */ = {isa = PBXBuildFile; fileRef = 74B918552319AE0300ADDEA4 /* BookDetailViewController+Safari.swift */; };
+		74B918582319B2CF00ADDEA4 /* CoreDataClient.swift in Sources */ = {isa = PBXBuildFile; fileRef = 74B918572319B2CF00ADDEA4 /* CoreDataClient.swift */; };
+		74B9185B2319B2DD00ADDEA4 /* Book.xcdatamodeld in Sources */ = {isa = PBXBuildFile; fileRef = 74B918592319B2DD00ADDEA4 /* Book.xcdatamodeld */; };
 		768F74E39672B1F50C632913 /* Pods_iOSBooks.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 2D2FDB2EC5907498F6A3C173 /* Pods_iOSBooks.framework */; };
 /* End PBXBuildFile section */
 
@@ -89,6 +91,8 @@
 		74B9185123199E8F00ADDEA4 /* BookDetailViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = BookDetailViewModel.swift; sourceTree = "<group>"; };
 		74B9185323199F4500ADDEA4 /* BookDetailViewController+View.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "BookDetailViewController+View.swift"; sourceTree = "<group>"; };
 		74B918552319AE0300ADDEA4 /* BookDetailViewController+Safari.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "BookDetailViewController+Safari.swift"; sourceTree = "<group>"; };
+		74B918572319B2CF00ADDEA4 /* CoreDataClient.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoreDataClient.swift; sourceTree = "<group>"; };
+		74B9185A2319B2DD00ADDEA4 /* Book.xcdatamodel */ = {isa = PBXFileReference; lastKnownFileType = wrapper.xcdatamodel; path = Book.xcdatamodel; sourceTree = "<group>"; };
 		E6741F045EBC12BB315EE1CB /* Pods-iOSBooks.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-iOSBooks.debug.xcconfig"; path = "Target Support Files/Pods-iOSBooks/Pods-iOSBooks.debug.xcconfig"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -212,6 +216,8 @@
 			isa = PBXGroup;
 			children = (
 				7447D3652316E3C100E01BD3 /* BooksClient.swift */,
+				74B918572319B2CF00ADDEA4 /* CoreDataClient.swift */,
+				74B918592319B2DD00ADDEA4 /* Book.xcdatamodeld */,
 			);
 			path = Clients;
 			sourceTree = "<group>";
@@ -504,9 +510,11 @@
 				74ADE9BE23196CE3006D2644 /* AppCoordinatorDependencyInjector.swift in Sources */,
 				7447D3702316F14D00E01BD3 /* SalesInfo.swift in Sources */,
 				7447D37A2316F71200E01BD3 /* BooksListViewModel.swift in Sources */,
+				74B918582319B2CF00ADDEA4 /* CoreDataClient.swift in Sources */,
 				7447D36E2316F13A00E01BD3 /* ImageLinks.swift in Sources */,
 				7447D37C2316F71D00E01BD3 /* BooksListViewController.swift in Sources */,
 				74ADE9C7231973B5006D2644 /* BooksListViewController+CollectionView.swift in Sources */,
+				74B9185B2319B2DD00ADDEA4 /* Book.xcdatamodeld in Sources */,
 				74ADE9C52319730F006D2644 /* BooksCell.swift in Sources */,
 				74ADE9D223199D97006D2644 /* BookDetailViewController.swift in Sources */,
 				74ADE9B823196A7A006D2644 /* AppCoordinator.swift in Sources */,
@@ -786,6 +794,19 @@
 			defaultConfigurationName = Release;
 		};
 /* End XCConfigurationList section */
+
+/* Begin XCVersionGroup section */
+		74B918592319B2DD00ADDEA4 /* Book.xcdatamodeld */ = {
+			isa = XCVersionGroup;
+			children = (
+				74B9185A2319B2DD00ADDEA4 /* Book.xcdatamodel */,
+			);
+			currentVersion = 74B9185A2319B2DD00ADDEA4 /* Book.xcdatamodel */;
+			path = Book.xcdatamodeld;
+			sourceTree = "<group>";
+			versionGroupType = wrapper.xcdatamodel;
+		};
+/* End XCVersionGroup section */
 	};
 	rootObject = 0E3964CC2314BB470093738B /* Project object */;
 }

iOSBooks/iOSBooks/AppDelegate.swift

@@ -6,7 +6,7 @@
 //  Copyright © 2019 Guilherme Antunes. All rights reserved.
 //
 
-import IQKeyboardManagerSwift
+import CoreData
 import UIKit
 
 @UIApplicationMain
@@ -22,8 +22,6 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
             print("window is unexpectedly nil")
             return false
         }
-        IQKeyboardManager.shared.enable = true
-        IQKeyboardManager.shared.shouldShowToolbarPlaceholder = false
         coordinator = AppCoordinator(window: window)
         coordinator?.start()
 
@@ -51,7 +49,51 @@ class AppDelegate: UIResponder, UIApplicationDelegate {
     func applicationWillTerminate(_ application: UIApplication) {
         window = nil
     }
+
+    // MARK: - Core Data stack
+
+    lazy var persistentContainer: NSPersistentContainer = {
+        /*
+         The persistent container for the application. This implementation
+         creates and returns a container, having loaded the store for the
+         application to it. This property is optional since there are legitimate
+         error conditions that could cause the creation of the store to fail.
+         */
+        let container = NSPersistentContainer(name: "Book")
+        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
+            if let error = error as NSError? {
+                // Replace this implementation with code to handle the error appropriately.
+                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
+
+                /*
+                 Typical reasons for an error here include:
+                 * The parent directory does not exist, cannot be created, or disallows writing.
+                 * The persistent store is not accessible, due to permissions or data protection when the device is locked.
+                 * The device is out of space.
+                 * The store could not be migrated to the current model version.
+                 Check the error message to determine what the actual problem was.
+                 */
+                fatalError("Unresolved error \(error), \(error.userInfo)")
+            }
+        })
+        return container
+    }()
 
+    // MARK: - Core Data Saving support
+
+    func saveContext () {
+        let context = persistentContainer.viewContext
+        if context.hasChanges {
+            do {
+                try context.save()
+            } catch {
+                // Replace this implementation with code to handle the error appropriately.
+                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
+                let nserror = error as NSError
+                fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
+            }
+        }
+    }
 
 }
 

iOSBooks/iOSBooks/BookDetail/View/BookDetail.storyboard

@@ -54,14 +54,26 @@
                                     </textView>
                                 </subviews>
                             </stackView>
+                            <button opaque="NO" contentMode="scaleToFill" contentHorizontalAlignment="center" contentVerticalAlignment="center" buttonType="roundedRect" lineBreakMode="middleTruncation" translatesAutoresizingMaskIntoConstraints="NO" id="4yx-Iu-LCN">
+                                <rect key="frame" x="330" y="56" width="72" height="37"/>
+                                <fontDescription key="fontDescription" name="AvenirNext-Regular" family="Avenir Next" pointSize="18"/>
+                                <state key="normal" title="Favoritar">
+                                    <color key="titleColor" red="0.0" green="0.0" blue="0.0" alpha="1" colorSpace="custom" customColorSpace="sRGB"/>
+                                </state>
+                                <connections>
+                                    <action selector="saveBook:" destination="6rU-Uw-H3q" eventType="touchUpInside" id="tMi-uV-QFL"/>
+                                </connections>
+                            </button>
                         </subviews>
                         <color key="backgroundColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
                         <constraints>
                             <constraint firstItem="DsL-0l-xi7" firstAttribute="leading" secondItem="SrW-hW-4OI" secondAttribute="leading" constant="12" id="A9U-Mz-1My"/>
                             <constraint firstItem="DsL-0l-xi7" firstAttribute="top" secondItem="TpO-b0-I35" secondAttribute="bottom" constant="12" id="NTd-sh-A5j"/>
+                            <constraint firstItem="SrW-hW-4OI" firstAttribute="trailing" secondItem="4yx-Iu-LCN" secondAttribute="trailing" constant="12" id="P14-Py-Px5"/>
                             <constraint firstItem="TpO-b0-I35" firstAttribute="leading" secondItem="SrW-hW-4OI" secondAttribute="leading" constant="12" id="Psc-l9-6GA"/>
                             <constraint firstAttribute="bottom" secondItem="DsL-0l-xi7" secondAttribute="bottom" id="chY-Lh-qBo"/>
                             <constraint firstItem="SrW-hW-4OI" firstAttribute="trailing" secondItem="DsL-0l-xi7" secondAttribute="trailing" constant="12" id="doA-ib-ugT"/>
+                            <constraint firstItem="4yx-Iu-LCN" firstAttribute="top" secondItem="SrW-hW-4OI" secondAttribute="top" constant="12" id="gS0-BO-Ivy"/>
                             <constraint firstItem="TpO-b0-I35" firstAttribute="top" secondItem="SrW-hW-4OI" secondAttribute="top" constant="12" id="y6M-gB-GD3"/>
                         </constraints>
                         <viewLayoutGuide key="safeArea" id="SrW-hW-4OI"/>
@@ -72,6 +84,7 @@
                         <outlet property="bookTitleLabel" destination="768-XD-nlZ" id="z92-Hg-c8F"/>
                         <outlet property="buyLinkLabel" destination="baa-VJ-mqK" id="2ro-Qf-yqx"/>
                         <outlet property="descriptionTextView" destination="AgA-qA-aED" id="zGM-Go-3v2"/>
+                        <outlet property="favoriteButton" destination="4yx-Iu-LCN" id="pHx-y7-Mep"/>
                     </connections>
                 </viewController>
                 <placeholder placeholderIdentifier="IBFirstResponder" id="7Zi-CG-FdX" userLabel="First Responder" sceneMemberID="firstResponder"/>

iOSBooks/iOSBooks/BookDetail/View/BookDetailViewController+View.swift

@@ -21,8 +21,11 @@ extension BookDetailViewController: BookDetailViewControllerPresentable {
     }
 
     func setupView() {
+        if let button = favoriteButton {
+            toggleFavoriteButton(button)
+        }
         title = viewModel?.getScreenTitle()
-        bookImageView?.kf.setImage(with: viewModel?.getBookImageLink())
+        bookImageView?.kf.setImage(with: viewModel?.getBookImageLink(), options: [.cacheOriginalImage])
         bookTitleLabel?.text = viewModel?.getBookTitle()
         bookAuthorsLabel?.text = viewModel?.getBookAuthors()
         buyLinkLabel?.text = viewModel?.getBookBuyLink()
@@ -34,4 +37,14 @@ extension BookDetailViewController: BookDetailViewControllerPresentable {
         setBackButton(#selector(dismissScreen))
     }
 
+    func toggleFavoriteButton(_ button: UIButton) {
+        button.layer.cornerRadius = 10
+        guard let viewModel = viewModel else { return }
+        if viewModel.savedBook {
+            button.backgroundColor = .yellow
+            return
+        }
+        button.backgroundColor = .white
+    }
+
 }

iOSBooks/iOSBooks/BookDetail/View/BookDetailViewController.swift

@@ -16,6 +16,7 @@ class BookDetailViewController: UIViewController {
     @IBOutlet weak var bookAuthorsLabel: UILabel?
     @IBOutlet weak var buyLinkLabel: UILabel?
     @IBOutlet weak var descriptionTextView: UITextView?
+    @IBOutlet weak var favoriteButton: UIButton?
 
     // MARK: - Properties
     var viewModel: BookDetailViewModelProtocol?
@@ -36,4 +37,11 @@ class BookDetailViewController: UIViewController {
     @objc func dismissScreen() {
         viewModel?.presentPreviousStep()
     }
+
+    // MARK: - Actions
+    @IBAction func saveBook(_ sender: UIButton) {
+        viewModel?.saveBookIfNeeded()
+        toggleFavoriteButton(sender)
+    }
+
 }

iOSBooks/iOSBooks/BookDetail/ViewModel/BookDetailViewModel.swift

@@ -17,6 +17,8 @@ protocol BookDetailViewModelProtocol {
     func presentPreviousStep()
     func getScreenTitle() -> String?
     func getBookBuyLinkURL() -> URL?
+    func saveBookIfNeeded()
+    var savedBook: Bool { get }
 }
 
 class BookDetailViewModel: BookDetailViewModelProtocol {
@@ -25,6 +27,8 @@ class BookDetailViewModel: BookDetailViewModelProtocol {
     var selectedBook: Item?
     weak var view: BookDetailViewControllerPresentable?
     var coordinator: AppCoordinatorProtocol?
+    var service = CoreDataClient()
+    var savedBook: Bool = false
 
     // MARK: - ViewModel Protocol Methods
     func getBookTitle() -> String {
@@ -72,4 +76,19 @@ class BookDetailViewModel: BookDetailViewModelProtocol {
 
         return nil
     }
+
+    func saveBookIfNeeded() {
+        if savedBook {
+            deleteBook()
+            return
+        }
+        savedBook = true
+        service.saveBook(selectedBook)
+    }
+
+    func deleteBook() {
+        savedBook = false
+        service.deleteBook(selectedBook)
+
+    }
 }

iOSBooks/iOSBooks/BooksList/View/BooksListViewController+View.swift

@@ -15,6 +15,9 @@ protocol BooksListViewControllerPresentable: class {
 
 extension BooksListViewController: BooksListViewControllerPresentable {
     func reloadView() {
+        if let viewModel = viewModel {
+            title = viewModel.showFavorites ? "Favorites iOS Books" : "iOS Books"
+        }
         booksCollectionView?.reloadData()
     }
 
@@ -23,12 +26,26 @@ extension BooksListViewController: BooksListViewControllerPresentable {
     }
 
     func setupCollectionView()  {
-        title = "iOS Books"
         booksCollectionView?.dataSource = self
         booksCollectionView?.delegate = self
     }
 
     func setupNavigationBar() {
         navigationController?.navigationBar.prefersLargeTitles = true
     }
+
+    @objc func fillWithSavedBooks() {
+        guard var viewModel = viewModel else { return }
+        if !viewModel.showFavorites {
+            viewModel.showFavorites.toggle()
+            viewModel.loadSavedBooks(shouldShowOnScreen: true)
+            return
+        }
+        viewModel.showFavorites.toggle()
+        reloadView()
+    }
+
+    func setupFavoritesFilterButton() {
+        navigationItem.rightBarButtonItem = button
+    }
 }

iOSBooks/iOSBooks/BooksList/View/BooksListViewController.swift

@@ -9,19 +9,25 @@
 import UIKit
 
 class BooksListViewController: UIViewController {
+
+    // MARK: - Outlets
+    @IBOutlet weak var booksCollectionView: UICollectionView?
 
     // MARK: - Properties
     var viewModel: BooksListViewModelProtocol?
-    @IBOutlet weak var booksCollectionView: UICollectionView?
+    lazy var button = UIBarButtonItem(barButtonSystemItem: .bookmarks, target: self, action: #selector(fillWithSavedBooks))
 
     // MARK: - View Life Cycle
     override func viewDidLoad() {
         setupCollectionView()
-        viewModel?.loadBooks()
+        setupFavoritesFilterButton()
     }
 
     override func viewWillAppear(_ animated: Bool) {
         super.viewWillAppear(animated)
         setupNavigationBar()
+        viewModel?.loadSavedBooks(shouldShowOnScreen: false)
+        viewModel?.showFavorites = false
+        viewModel?.loadBooks()
     }
 }

iOSBooks/iOSBooks/BooksList/View/Subviews/BooksCell.swift

@@ -10,20 +10,42 @@ import Kingfisher
 import UIKit
 
 class BooksCell: UICollectionViewCell {
+
+    // MARK: - Outlets
     @IBOutlet weak var bookImageView: UIImageView?
 
+    // MARK: - Properties
+    var selectedBook: Book?
+    lazy var imageCache = ImageCache(name: selectedBook?.title ?? "")
+
     func setup(withBook book: Book?) {
-        if let book = book, let bookURLString = book.imageLinks?.smallThumbnail, let url = URL(string: bookURLString) {
-            bookImageView?.kf.setImage(with: url)
+        selectedBook = book
+        if let image = imageCache.retrieveImageInMemoryCache(forKey: selectedBook?.subtitle ?? "") {
+            bookImageView?.image = image
+        } else {
+            if let book = book, let bookURLString = book.imageLinks?.smallThumbnail, let url = URL(string: bookURLString) {
+                bookImageView?.kf.setImage(with: url, options: [.cacheOriginalImage], completionHandler: { (result) in
+                    switch result {
+                    case .success(let result):
+                        self.imageCache.store(result.image, forKey: self.selectedBook?.subtitle ?? "")
+                    case .failure(let error):
+                        print(error.localizedDescription)
+                    }
+                })
+
+            }
         }
+
     }
 
     override func prepareForReuse() {
         super.prepareForReuse()
+        bookImageView?.image = nil
         bookImageView?.kf.cancelDownloadTask()
     }
 
     deinit {
+        bookImageView?.image = nil
         bookImageView?.kf.cancelDownloadTask()
     }