Merge pull request #18 from ra1028/lazy-target-assigning

Lazy target assigning

Carbon.xcodeproj/project.pbxproj

@@ -56,6 +56,7 @@
 		6B7ADEF421FDB12B003803BE /* UITableViewComponentHeaderFooterViewTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6B7ADEF021FDB12A003803BE /* UITableViewComponentHeaderFooterViewTests.swift */; };
 		6B7EED9E224CA5DD00060872 /* UIScrollViewExtensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6B7EED9D224CA5DD00060872 /* UIScrollViewExtensions.swift */; };
 		6B7EEDA0224CE4E100060872 /* UIScrollViewExtensionsTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6B7EED9F224CE4E000060872 /* UIScrollViewExtensionsTests.swift */; };
+		6BAEA3DA2289C5D10026F81E /* Deprecated.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6BAEA3D92289C5D10026F81E /* Deprecated.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -122,6 +123,7 @@
 		6B7ADEF021FDB12A003803BE /* UITableViewComponentHeaderFooterViewTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = UITableViewComponentHeaderFooterViewTests.swift; sourceTree = "<group>"; };
 		6B7EED9D224CA5DD00060872 /* UIScrollViewExtensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UIScrollViewExtensions.swift; sourceTree = "<group>"; };
 		6B7EED9F224CE4E000060872 /* UIScrollViewExtensionsTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UIScrollViewExtensionsTests.swift; sourceTree = "<group>"; };
+		6BAEA3D92289C5D10026F81E /* Deprecated.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Deprecated.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -175,6 +177,7 @@
 				6B65949021E2532100291AAF /* Section.swift */,
 				6B6594A321E2532100291AAF /* Renderer.swift */,
 				6B5304522201EDB200A3E21E /* DataChangeset.swift */,
+				6BAEA3D92289C5D10026F81E /* Deprecated.swift */,
 				6B65948921E2532100291AAF /* Adapters */,
 				6B65949221E2532100291AAF /* Updaters */,
 				6B65949D21E2532100291AAF /* Interfaces */,
@@ -439,6 +442,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				6BAEA3DA2289C5D10026F81E /* Deprecated.swift in Sources */,
 				6B6594BB21E2532100291AAF /* UITableViewComponentHeaderFooterView.swift in Sources */,
 				6B7EED9E224CA5DD00060872 /* UIScrollViewExtensions.swift in Sources */,
 				6B6594AC21E2532100291AAF /* Section.swift in Sources */,

Examples/Example-iOS/Sources/Emoji/EmojiViewController.swift

@@ -9,8 +9,7 @@ final class EmojiViewController: UIViewController {
     @IBOutlet var collectionView: UICollectionView!
     @IBOutlet var toolBar: UIToolbar!
 
-    private lazy var renderer = Renderer(
-        target: collectionView,
+    private let renderer = Renderer(
         adapter: UICollectionViewFlowLayoutAdapter(),
         updater: UICollectionViewUpdater()
     )
@@ -25,6 +24,8 @@ final class EmojiViewController: UIViewController {
         title = "Shuffle Emoji"
         toolBar.isTranslucent = false
         collectionView.contentInset.bottom = 44
+
+        renderer.target = collectionView
         renderer.updater.alwaysRenderVisibleComponents = true
 
         refresh()

Examples/Example-iOS/Sources/Form/FormViewController.swift

@@ -36,8 +36,7 @@ final class FormViewController: UIViewController {
         didSet { render() }
     }
 
-    private lazy var renderer = Renderer(
-        target: tableView,
+    private let renderer = Renderer(
         adapter: UITableViewAdapter(),
         updater: UITableViewUpdater()
     )
@@ -50,6 +49,7 @@ final class FormViewController: UIViewController {
         tableView.estimatedRowHeight = UITableView.automaticDimension
         NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillChangeFrame), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
 
+        renderer.target = tableView
         renderer.updater.deleteRowsAnimation = .middle
         renderer.updater.insertRowsAnimation = .middle
         renderer.updater.insertSectionsAnimation = .top

Examples/Example-iOS/Sources/Hello/HelloViewController.swift

@@ -12,8 +12,7 @@ final class HelloViewController: UIViewController {
         didSet { render() }
     }
 
-    private lazy var renderer = Renderer(
-        target: tableView,
+    private let renderer = Renderer(
         adapter: UITableViewAdapter(),
         updater: UITableViewUpdater()
     )
@@ -23,6 +22,7 @@ final class HelloViewController: UIViewController {
 
         title = "Hello"
         tableView.contentInset.top = 44
+        renderer.target = tableView
 
         render()
     }

Examples/Example-iOS/Sources/Kyoto/KyotoViewController.swift

@@ -9,8 +9,7 @@ final class KyotoViewController: UIViewController {
 
     @IBOutlet var collectionView: UICollectionView!
 
-    private lazy var renderer = Renderer(
-        target: collectionView,
+    private let renderer = Renderer(
         adapter: UICollectionViewFlowLayoutAdapter(),
         updater: UICollectionViewUpdater()
     )
@@ -21,6 +20,7 @@ final class KyotoViewController: UIViewController {
         title = "Kyoto"
         collectionView.contentInset.bottom = 24
 
+        renderer.target = collectionView
         renderer.render(
             Section(
                 id: ID.top,

Examples/Example-iOS/Sources/Pangram/PangramViewController.swift

@@ -5,8 +5,7 @@ final class PangramViewController: UIViewController {
     @IBOutlet var collectionView: UICollectionView!
     @IBOutlet var toolBar: UIToolbar!
 
-    private lazy var renderer = Renderer(
-        target: collectionView,
+    private let renderer = Renderer(
         adapter: UICollectionViewFlowLayoutAdapter(),
         updater: UICollectionViewUpdater()
     )
@@ -21,6 +20,7 @@ final class PangramViewController: UIViewController {
         title = "Pangram"
         toolBar.isTranslucent = false
         collectionView.contentInset.top = 44
+        renderer.target = collectionView
 
         render()
     }

Examples/Example-iOS/Sources/Todo/TodoViewController.swift

@@ -23,8 +23,7 @@ final class TodoViewController: UIViewController, UITextViewDelegate {
         didSet { render() }
     }
 
-    private lazy var renderer = Renderer(
-        target: tableView,
+    private let renderer = Renderer(
         adapter: TodoTableViewAdapter(),
         updater: UITableViewUpdater()
     )
@@ -42,6 +41,8 @@ final class TodoViewController: UIViewController, UITextViewDelegate {
         tableView.rowHeight = UITableView.automaticDimension
         tableView.estimatedRowHeight = UITableView.automaticDimension
         tableView.contentInset.bottom = view.bounds.height - addButton.frame.minY
+
+        renderer.target = tableView
         renderer.updater.skipReloadComponents = true
         renderer.updater.alwaysRenderVisibleComponents = true
 

Examples/Example-iOS/Sources/Top/HomeViewController.swift

@@ -17,8 +17,7 @@ final class HomeViewController: UIViewController {
 
     @IBOutlet var tableView: UITableView!
 
-    private lazy var renderer = Renderer(
-        target: tableView,
+    private let renderer = Renderer(
         adapter: UITableViewAdapter(),
         updater: UITableViewUpdater()
     )
@@ -28,6 +27,7 @@ final class HomeViewController: UIViewController {
 
         title = "Home"
 
+        renderer.target = tableView
         renderer.render(
             Section(
                 id: ID.examples,

README.md

@@ -195,21 +195,31 @@ Since there are several style syntaxes for passing group of sections, please che
 ```swift
 @IBOutlet var tableView: UITableView!
 
-lazy var renderer = Renderer(
-    target: tableView,
+let renderer = Renderer(
     adapter: UITableViewAdapter(),
     updater: UITableViewUpdater()
 )
+
+override func viewDidAppear(_ animated: Bool) {
+    super.viewDidAppear(animated)
+
+    renderer.target = tableView
+}
 ```
 
 ```swift
 @IBOutlet var collectionView: UICollectionView!
 
-lazy var renderer = Renderer(
-    target: collectionView,
+let renderer = Renderer(
     adapter: UICollectionViewFlowLayoutAdapter(),
     updater: UICollectionViewUpdater()
 )
+
+override func viewDidAppear(_ animated: Bool) {
+    super.viewDidAppear(animated)
+
+    renderer.target = collectionView
+}
 ```
 
 ```swift
@@ -397,6 +407,10 @@ Below are some of the default provided settings of `updater`.
 Indicating whether enables animation for diffing updates, setting `false` will perform it using `UIView.performWithoutAnimation`.  
 Default is `true`.  
 
+- **isAnimationEnabledWhileScrolling**  
+Indicating whether enables animation for diffing updates while target is scrolling, setting `false` will perform it  using `UIView.performWithoutAnimation`.  
+Default is `true`.  
+
 - **animatableChangeCount**  
 The max number of changes to perform diffing updates. It falls back to `reloadData` if it exceeded.  
 Default is `300`.  

Sources/Deprecated.swift

@@ -0,0 +1,10 @@
+public extension Renderer {
+    /// Create a new instance with given target, adapter and updater.
+    /// Immediately the `prepare` of updater is called.
+    @available(*, deprecated, message:"Use the `Renderer.init` that accepts only `adapter` and `updater` parameters, and set `target` at arbitrary timing.")
+    convenience init(target: Updater.Target, adapter: Updater.Adapter, updater: Updater) {
+        self.init(adapter: adapter, updater: updater)
+        self.target = target
+        updater.prepare(target: target, adapter: adapter)
+    }
+}

Sources/Renderer.swift

@@ -8,12 +8,14 @@ import UIKit
 ///
 /// Example for render a section containing simple nodes.
 ///
+///     let tableView: UITableView = ...
 ///     let renderer = Renderer(
-///         target: tableView,
 ///         adapter: UITableViewAdapter(),
 ///         updater: UITableViewUpdater()
 ///     )
 ///
+///     renderer.target = tableView
+///
 ///     renderer.render(
 ///         Section(
 ///             id: "section",
@@ -27,30 +29,32 @@ import UIKit
 ///         )
 ///     )
 open class Renderer<Updater: Carbon.Updater> {
-    /// An instance of target that weakly referenced.
-    public private(set) weak var target: Updater.Target?
-
     /// An instance of adapter that specified at initialized.
     public let adapter: Updater.Adapter
 
     /// An instance of updater that specified at initialized.
     public let updater: Updater
 
+    /// An instance of target that weakly referenced.
+    /// It will be passed to the `prepare` method of updater at didSet.
+    open weak var target: Updater.Target? {
+        didSet {
+            guard let target = target else { return }
+            updater.prepare(target: target, adapter: adapter)
+        }
+    }
+
     /// Returns a current data held in adapter.
     /// When data is set, it renders to the target immediately.
     open var data: [Section] {
         get { return adapter.data }
         set(data) { render(data) }
     }
 
-    /// Create a new instance with given target, adapter and updater.
-    /// Immediately the `prepare` of updater is called.
-    public init(target: Updater.Target, adapter: Updater.Adapter, updater: Updater) {
-        self.target = target
+    /// Create a new instance with given adapter and updater.
+    public init(adapter: Updater.Adapter, updater: Updater) {
         self.adapter = adapter
         self.updater = updater
-
-        updater.prepare(target: target, adapter: adapter)
     }
 
     /// Render given collection of sections, immediately.
@@ -59,12 +63,15 @@ open class Renderer<Updater: Carbon.Updater> {
     ///   - data: A collection of sections to be rendered.
     ///   - completion: A completion handler to be called after rendered.
     open func render<C: Collection>(_ data: C, completion: (() -> Void)? = nil) where C.Element == Section {
+        let data = Array(data)
+
         guard let target = target else {
+            adapter.data = data
             completion?()
             return
         }
 
-        updater.performUpdates(target: target, adapter: adapter, data: Array(data), completion: completion)
+        updater.performUpdates(target: target, adapter: adapter, data: data, completion: completion)
     }
 
     /// Render given collection of sections after removes contained nil, immediately.

Tests/RendererTests.swift

@@ -5,10 +5,10 @@ final class RendererTests: XCTestCase {
     func testTargetWeakCapture() {
         var target: MockTarget? = MockTarget()
         let renderer = Renderer(
-            target: target!,
             adapter: MockAdapter(),
             updater: MockUpdater()
         )
+        renderer.target = target
 
         target = nil
         XCTAssertNil(renderer.target)
@@ -18,24 +18,39 @@ final class RendererTests: XCTestCase {
         let target = MockTarget()
         let adapter = MockAdapter()
         let renderer = Renderer(
-            target: target,
             adapter: adapter,
             updater: MockUpdater()
         )
+        renderer.target = target
 
         XCTAssertEqual(renderer.updater.targetCapturedOnPrepare, target)
         XCTAssertEqual(renderer.updater.adapterCapturedOnPrepare, adapter)
     }
 
+    func testRenderBeforeTargetIsSet() {
+        let adapter = MockAdapter()
+        let renderer = Renderer(
+            adapter: adapter,
+            updater: MockUpdater()
+        )
+
+        renderer.render(
+            Section(id: TestID.a),
+            Section(id: TestID.b)
+        )
+
+        XCTAssertEqual(renderer.adapter.data.count, 2)
+    }
+
     func testDataSetter() {
         let target = MockTarget()
         let adapter = MockAdapter()
         let renderer = Renderer(
-            target: target,
             adapter: adapter,
             updater: MockUpdater()
         )
 
+        renderer.target = target
         renderer.data = [
             Section(id: TestID.a),
             Section(id: TestID.b),
@@ -51,10 +66,10 @@ final class RendererTests: XCTestCase {
         let target = MockTarget()
         let adapter = MockAdapter()
         let renderer = Renderer(
-            target: target,
             adapter: adapter,
             updater: MockUpdater()
         )
+        renderer.target = target
 
         var completed = false
         let data = [
@@ -77,10 +92,10 @@ final class RendererTests: XCTestCase {
         let target = MockTarget()
         let adapter = MockAdapter()
         let renderer = Renderer(
-            target: target,
             adapter: adapter,
             updater: MockUpdater()
         )
+        renderer.target = target
 
         var completed = false
         let data = [
@@ -105,10 +120,10 @@ final class RendererTests: XCTestCase {
         let target = MockTarget()
         let adapter = MockAdapter()
         let renderer = Renderer(
-            target: target,
             adapter: adapter,
             updater: MockUpdater()
         )
+        renderer.target = target
 
         var completed = false
 
@@ -131,10 +146,10 @@ final class RendererTests: XCTestCase {
         let target = MockTarget()
         let adapter = MockAdapter()
         let renderer = Renderer(
-            target: target,
             adapter: adapter,
             updater: MockUpdater()
         )
+        renderer.target = target
 
         var completed = false