Add a method that can replace items of a section.

DeclarativeHub · Mar 26, 2019 · f1f3d23 · f1f3d23
1 parent 24fb161
commit f1f3d23
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Showing 3 changed files with 26 additions and 0 deletions.
diff --git a/...d-iOS.playground/Pages/UICollectionView+ObservableArray2D.xcplaygroundpage/Contents.swift b/...d-iOS.playground/Pages/UICollectionView+ObservableArray2D.xcplaygroundpage/Contents.swift
@@ -114,4 +114,7 @@ DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
     data.moveItem(from: IndexPath(item: 0, section: 1), to: IndexPath(item: 0, section: 0))
 }
 
+DispatchQueue.main.asyncAfter(deadline: .now() + 4) {
+    data.replaceItems(ofSectionAt: 1, with: [1, 100, 20], performDiff: true)
+}
 //: [Next](@next)
diff --git a/...ground-iOS.playground/Pages/UITableView+ObservableArray2D.xcplaygroundpage/Contents.swift b/...ground-iOS.playground/Pages/UITableView+ObservableArray2D.xcplaygroundpage/Contents.swift
@@ -8,6 +8,7 @@ import ReactiveKit
 
 let tableView = UITableView()
 tableView.frame.size = CGSize(width: 300, height: 600)
+tableView.rowHeight = 40
 
 // Note: Open the assistant editor to see the table view
 PlaygroundPage.current.liveView = tableView
@@ -54,4 +55,8 @@ DispatchQueue.main.asyncAfter(deadline: .now() + 3) {
     data.moveItem(from: IndexPath(item: 0, section: 1), to: IndexPath(item: 0, section: 0))
 }
 
+DispatchQueue.main.asyncAfter(deadline: .now() + 4) {
+    data.replaceItems(ofSectionAt: 1, with: [1, 100, 20], performDiff: true)
+}
+
 //: [Next](@next)
diff --git a/Sources/Bond/Observable Collections/TreeChangeset+Array2D.swift b/Sources/Bond/Observable Collections/TreeChangeset+Array2D.swift
@@ -127,3 +127,21 @@ extension MutableChangesetContainerProtocol where Changeset: TreeChangesetProtoc
         removeAll()
     }
 }
+
+extension MutableChangesetContainerProtocol where Changeset: TreeChangesetProtocol, Changeset.Collection: Array2DProtocol, Changeset.Collection.Item: Equatable {
+
+    /// Replace items of a section at the given index with new items. Setting `performDiff: true` will make the framework
+    /// calculate the diff between the existing and new items and emit an event with the calculated diff.
+    public func replaceItems(ofSectionAt sectionIndex: Int, with newItems: [Item], performDiff: Bool) {
+        guard performDiff else {
+            self[sectionAt: sectionIndex].items = newItems
+            return
+        }
+        let currentItems = self[sectionAt: sectionIndex].items
+        let diff = OrderedCollectionDiff<Int>(from: currentItems.extendedDiff(newItems, isEqual: ==))
+        descriptiveUpdate { (collection) -> Diff in
+            collection[childAt: [sectionIndex]].children = newItems.map { Array2D.Node.item($0) }
+            return diff.map { [sectionIndex, $0] }
+        }
+    }
+}