added state change support in DivKitSample

client/ios/Sample/DivKitSample/DivHostView.swift

@@ -6,7 +6,7 @@ import LayoutKit
 
 final class DivHostView: UICollectionView {
   private let components: DivKitComponents
-  private var blocks: [Block] = []
+  private var items: [Item] = []
 
   init(components: DivKitComponents) {
     self.components = components
@@ -24,22 +24,46 @@ final class DivHostView: UICollectionView {
     fatalError("init(coder:) has not been implemented")
   }
 
-  func setCards(_ cards: [DivData]) {
-    self.blocks = cards.compactMap { card in
-      let context = components.makeContext(
-        cardId: DivCardID(rawValue: card.logId),
-        cachedImageHolders: []
-      )
-      return try? card.makeBlock(context: context)
+  func setData(_ items: [DivData]) {
+    self.items = items.compactMap { makeItem(data: $0) }
+  }
+  
+  func reloadItem(cardId: String) {
+    guard let index = items.firstIndex(where: { $0.data.logId == cardId }) else {
+      return
     }
+    
+    let item = items[index]
+    items[index] = makeItem(
+      data: item.data,
+      cachedImageHolders: item.block.getImageHolders()
+    )
+    
+    reloadItems(at: [IndexPath(item: index, section: 0)])
   }
 
+  private func makeItem(
+    data: DivData,
+    cachedImageHolders: [ImageHolder] = []
+  ) -> Item {
+    let context = components.makeContext(
+      cardId: DivCardID(rawValue: data.logId),
+      cachedImageHolders: cachedImageHolders
+    )
+    return Item(data: data, block: try! data.makeBlock(context: context))
+  }
+  
+  private struct Item {
+    let data: DivData
+    let block: Block
+  }
+  
   private class Cell: UICollectionViewCell {
     static let reuseIdentifier = "cell"
 
     struct State {
-      var block: Block
-      var view: BlockView
+      let block: Block
+      let view: BlockView
     }
 
     var state: State?
@@ -66,21 +90,31 @@ final class DivHostView: UICollectionView {
 }
 
 extension DivHostView: UICollectionViewDataSource {
-  func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
-    return blocks.count
+  func collectionView(
+    _ collectionView: UICollectionView,
+    numberOfItemsInSection section: Int
+  ) -> Int {
+    return items.count
   }
 
-  func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
+  func collectionView(
+    _ collectionView: UICollectionView,
+    cellForItemAt indexPath: IndexPath
+  ) -> UICollectionViewCell {
     let cell = collectionView.dequeueReusableCell(withReuseIdentifier: Cell.reuseIdentifier, for: indexPath) as! Cell
-    let block = blocks[indexPath.row]
+    let block = items[indexPath.row].block
     cell.setBlock(block)
     return cell
   }
 }
 
 extension DivHostView: UICollectionViewDelegateFlowLayout {
-  func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
-    let block = blocks[indexPath.row]
+  func collectionView(
+    _ collectionView: UICollectionView,
+    layout collectionViewLayout: UICollectionViewLayout,
+    sizeForItemAt indexPath: IndexPath
+  ) -> CGSize {
+    let block = items[indexPath.row].block
     let height = block.heightOfVerticallyNonResizableBlock(forWidth: bounds.width)
     return CGSize(width: bounds.width, height: height)
   }

client/ios/Sample/DivKitSample/DivHostViewController.swift

@@ -2,9 +2,8 @@ import UIKit
 
 import DivKit
 import LayoutKit
-import Serialization
 
-class DivHostViewController: UIViewController {
+final class DivHostViewController: UIViewController {
   private var divHostView: DivHostView!
   private var components: DivKitComponents!
 
@@ -18,7 +17,7 @@ class DivHostViewController: UIViewController {
     
     if let cards = try? DivJson.loadCards() {
       view.addSubview(divHostView)
-      divHostView.setCards(cards)
+      divHostView.setData(cards)
     }
   }
 
@@ -33,6 +32,7 @@ extension DivHostViewController: UIActionEventPerforming {
     switch event.payload {
     case let .divAction(params):
       components.handleActions(params: params)
+      divHostView.reloadItem(cardId: params.cardId)
     case .empty,
          .url,
          .menu,

client/ios/Sample/DivKitSample/div_json.json

@@ -241,7 +241,7 @@
                 "avatar": "https://habrastorage.org/r/w32/getpro/habr/avatars/ba8/258/251/ba825825164ffb969217c5bd71ebcc3e.png",
                 "username": "danis_gaiazov",
                 "time": "6 июля в 10:59",
-                "title": "Как люди помогают технологиям в Яндекс Картах\n",
+                "title": "Как люди помогают технологиям в Яндекс Картах",
                 "votes": "+20",
                 "comments": "19 +19",
                 "views": "4.7K",