From f1b30368744dab5f288c7e636d8bd64a41012e40 Mon Sep 17 00:00:00 2001
From: Daniele Margutti <hello@danielemargutti.com>
Date: Wed, 22 Aug 2018 12:11:51 +0200
Subject: [PATCH] #4 Fixes for assertion in TableDirector update. Use
 performBatchUpdates in iOS 11+

---
 .../Table Example/TableViewController.swift   | 30 +++++++------
 Sources/Flow/Table/TableDirector.swift        | 44 ++++++++++++-------
 2 files changed, 45 insertions(+), 29 deletions(-)

diff --git a/ExampleApp/Table Example/TableViewController.swift b/ExampleApp/Table Example/TableViewController.swift
index 42e9972..7db1e36 100644
--- a/ExampleApp/Table Example/TableViewController.swift	
+++ b/ExampleApp/Table Example/TableViewController.swift	
@@ -15,19 +15,7 @@ class TableViewController: UIViewController {
 	override func viewDidLoad() {
 		super.viewDidLoad()
 
-		let articleAdpt = TableAdapter<Article,TableArticleCell>()
-		articleAdpt.on.dequeue = { ctx in
-			ctx.cell?.titleLabel?.text = ctx.model.title
-			ctx.cell?.subtitleLabel?.text = ctx.model.text
-		}
-		articleAdpt.on.tap = { ctx in
-			print("Tapped on article \(ctx.model.id)")
-			return .deselectAnimated
-		}
-		self.tableView?.director.register(adapter: articleAdpt)
-		
-		
-		
+		self.tableView?.director.register(adapter: ArticleAdapter())
 		self.tableView?.director.add(section: self.getWinnerSection())
 
 		self.tableView?.director.rowHeight = .autoLayout(estimated: 100)
@@ -82,6 +70,22 @@ class TableViewController: UIViewController {
 
 }
 
+public class ArticleAdapter: TableAdapter<Article,TableArticleCell> {
+	
+	init() {
+		super.init()
+		self.on.dequeue = { ctx in
+			ctx.cell?.titleLabel?.text = ctx.model.title
+			ctx.cell?.subtitleLabel?.text = ctx.model.text
+		}
+		self.on.tap = { ctx in
+			print("Tapped on article \(ctx.model.id)")
+			return .deselectAnimated
+		}
+	}
+	
+}
+
 public class Article: ModelProtocol, Hashable {
 	public var hashValue: Int {
 		return self.id.hashValue
diff --git a/Sources/Flow/Table/TableDirector.swift b/Sources/Flow/Table/TableDirector.swift
index 8c92eee..639c7bc 100644
--- a/Sources/Flow/Table/TableDirector.swift
+++ b/Sources/Flow/Table/TableDirector.swift
@@ -154,6 +154,7 @@ public class TableDirector: NSObject, UITableViewDelegate, UITableViewDataSource
 			return
 		}
 		
+		
 		// Keep a reference to removed items in order to perform diff and animation
 		let oldSections: [TableSection] = Array.init(self.sections)
 		var oldItemsInSections: [String: [ModelProtocol]] = [:]
@@ -162,26 +163,37 @@ public class TableDirector: NSObject, UITableViewDelegate, UITableViewDataSource
 		// Execute callback and return animations to perform
 		let animationsToPerform = (t(self) ?? TableReloadAnimations.default())
 
-		// Execute reload for sections
-		let changesInSection = SectionChanges.fromTableSections(old: oldSections, new: self.sections)
-		changesInSection.applyChanges(toTable: self.tableView, withAnimations: animationsToPerform)
-		
-		self.tableView?.beginUpdates()
-		self.sections.enumerated().forEach { (idx,newSection) in
-			if let oldSectionItems = oldItemsInSections[newSection.UUID] {
-				guard let oldItems = oldSectionItems as? [AnyHashable], let newItems = newSection.models as? [AnyHashable] else {
-					debugPrint("Malfunction: models in table must be conform to Hashable protocol in order to perform automatic diff")
-					return
+		func executeDiffAndUpdate() {
+			// Execute reload for sections
+			let changesInSection = SectionChanges.fromTableSections(old: oldSections, new: self.sections)
+			changesInSection.applyChanges(toTable: self.tableView, withAnimations: animationsToPerform)
+			
+			self.sections.enumerated().forEach { (idx,newSection) in
+				if let oldSectionItems = oldItemsInSections[newSection.UUID] {
+					guard let oldItems = oldSectionItems as? [AnyHashable], let newItems = newSection.models as? [AnyHashable] else {
+						debugPrint("Malfunction: models in table must be conform to Hashable protocol in order to perform automatic diff")
+						return
+					}
+					// models must conform to Hashable otherwise we are not able to perform diff
+					let diffData = diff(old: oldItems, new: newItems)
+					let itemChanges = SectionItemsChanges.create(fromChanges: diffData, section: idx)
+					itemChanges.applyChangesToSectionItems(ofTable: self.tableView, withAnimations: animationsToPerform)
 				}
-				// models must conform to Hashable otherwise we are not able to perform diff
-				let diffData = diff(old: oldItems, new: newItems)
-				let itemChanges = SectionItemsChanges.create(fromChanges: diffData, section: idx)
-				itemChanges.applyChangesToSectionItems(ofTable: self.tableView, withAnimations: animationsToPerform)
 			}
 		}
 		
-		self.tableView?.endUpdates()
-		DispatchQueue.main.asyncAfter(deadline: .now() + 0.25, execute: { onEnd?() })
+		if #available(iOS 11.0, *) {
+			self.tableView?.performBatchUpdates({
+				executeDiffAndUpdate()
+			}, completion: { end in
+				if end { onEnd?() }
+			})
+		} else {
+			self.tableView?.beginUpdates()
+			executeDiffAndUpdate()
+			self.tableView?.endUpdates()
+			DispatchQueue.main.asyncAfter(deadline: .now() + 0.25, execute: { onEnd?() })
+		}
 	}
 	
 	/// Change the content of the table.