[GWL-407] Refresh기능 구현 (#447)

* feat: HomeFeature DownSampling 모듈 추가

* feat: 다운 샘플링 적용

* feat: ImageCacher 및 PrepareForReuse 적용

* feat: Repository And UseCase 파일 생성

* feat: FetchCheckManager 구현

* move: 파일 위치 변경

* feat: coordaintor 및 UseCase 적용

* feat: 무한 스크롤 구현

* delete: 목 데이터 삭제

* feat: 화면에 피드가 표시되었을 때 Page넘버를 증가하는 기능 추가

* delete: Home화면 Resources 폴더 제거

* feat: UseCase, Repository에 refresh Feed 비지니스 로직 작성

* move: 파일 분리

* feat: 리프래시 기능 구현

Author: MaraMincho

iOS/Projects/Features/Home/Sources/Data/FeedRepository.swift

@@ -16,13 +16,14 @@ import Trinet
 public struct FeedRepository: FeedRepositoryRepresentable {
   let decoder = JSONDecoder()
   let provider: TNProvider<FeedEndPoint>
+
   init(session: URLSessionProtocol = URLSession.shared) {
     provider = .init(session: session)
   }
 
   public func fetchFeed(at page: Int) -> AnyPublisher<[FeedElement], Never> {
     return Future<[FeedElement], Error> { promise in
-      Task { [provider] in
+      Task {
         do {
           let data = try await provider.request(.fetchPosts(page: page), interceptor: TNKeychainInterceptor.shared)
           let feedElementList = try decoder.decode([FeedElement].self, from: data)
@@ -35,12 +36,30 @@ public struct FeedRepository: FeedRepositoryRepresentable {
     .catch { _ in return Empty() }
     .eraseToAnyPublisher()
   }
+
+  public func refreshFeed() -> AnyPublisher<[FeedElement], Never> {
+    return Future<[FeedElement], Error> { promise in
+      Task { [provider] in
+        do {
+          let data = try await provider.request(.refreshFeed, interceptor: TNKeychainInterceptor.shared)
+          let feedElementList = try decoder.decode([FeedElement].self, from: data)
+          promise(.success(feedElementList))
+        } catch {
+          promise(.failure(error))
+        }
+      }
+    }
+    .catch { _ in return Empty() }
+    .eraseToAnyPublisher()
+  }
 }
 
 // MARK: - FeedEndPoint
 
 public enum FeedEndPoint: TNEndPoint {
   case fetchPosts(page: Int)
+  case refreshFeed
+
   public var path: String {
     return ""
   }
@@ -57,6 +76,8 @@ public enum FeedEndPoint: TNEndPoint {
     switch self {
     case let .fetchPosts(page):
       return page
+    case .refreshFeed:
+      return nil
     }
   }
 

iOS/Projects/Features/Home/Sources/Domain/HomeUseCase.swift

@@ -13,6 +13,7 @@ import Foundation
 
 public protocol HomeUseCaseRepresentable {
   func fetchFeed() -> AnyPublisher<[FeedElement], Never>
+  func refreshFeed() -> AnyPublisher<[FeedElement], Never>
   mutating func didDisplayFeed()
 }
 
@@ -34,7 +35,11 @@ public struct HomeUseCase: HomeUseCaseRepresentable {
       return Empty().eraseToAnyPublisher()
     }
     checkManager[latestFeedPage] = true
-    return feedElementPublisher.eraseToAnyPublisher()
+    return feedRepositoryRepresentable.fetchFeed(at: latestFeedPage)
+  }
+
+  public func refreshFeed() -> AnyPublisher<[FeedElement], Never> {
+    return feedRepositoryRepresentable.refreshFeed()
   }
 
   public mutating func didDisplayFeed() {

iOS/Projects/Features/Home/Sources/Domain/RepositoryInterface/FeedRepositoryRepresentable.swift

@@ -13,4 +13,5 @@ import Foundation
 
 public protocol FeedRepositoryRepresentable {
   func fetchFeed(at page: Int) -> AnyPublisher<[FeedElement], Never>
+  func refreshFeed() -> AnyPublisher<[FeedElement], Never>
 }

iOS/Projects/Features/Home/Sources/Presntaion/HomeScene/VIew/FeedImageCell.swift

@@ -7,6 +7,7 @@
 //
 
 import Cacher
+import ImageDownsampling
 import UIKit
 
 // MARK: - FeedImageCell
@@ -55,6 +56,7 @@ final class FeedImageCell: UICollectionViewCell {
         guard let data = try? Data(contentsOf: imageURL) else { return }
         DispatchQueue.main.async { [weak self] in
           self?.feedImage.image = UIImage(data: data)
+          self?.layoutIfNeeded()
         }
       }
       return

iOS/Projects/Features/Home/Sources/Presntaion/HomeScene/VIew/FeedItemCollectionViewCell.swift

@@ -6,6 +6,7 @@
 //  Copyright © 2023 kr.codesquad.boostcamp8. All rights reserved.
 //
 
+import Cacher
 import DesignSystem
 import UIKit
 

iOS/Projects/Features/Home/Sources/Presntaion/HomeScene/ViewController/HomeViewController+CompositionlLayout.swift

@@ -0,0 +1,24 @@
+//
+//  HomeViewController+CompositionlLayout.swift
+//  HomeFeature
+//
+//  Created by MaraMincho on 1/3/24.
+//  Copyright © 2024 kr.codesquad.boostcamp8. All rights reserved.
+//
+
+import UIKit
+
+extension HomeViewController {
+  static func makeFeedCollectionViewLayout() -> UICollectionViewCompositionalLayout {
+    let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .fractionalHeight(1))
+    let item = NSCollectionLayoutItem(layoutSize: itemSize)
+    item.contentInsets = .init(top: 9, leading: 0, bottom: 9, trailing: 0)
+
+    let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .estimated(455))
+    let group = NSCollectionLayoutGroup.vertical(layoutSize: groupSize, subitems: [item])
+
+    let section = NSCollectionLayoutSection(group: group)
+
+    return UICollectionViewCompositionalLayout(section: section)
+  }
+}

iOS/Projects/Features/Home/Sources/Presntaion/HomeScene/ViewController/HomeViewController.swift

@@ -7,6 +7,7 @@
 //
 
 import Combine
+import CombineCocoa
 import DesignSystem
 import Log
 import UIKit
@@ -24,6 +25,7 @@ final class HomeViewController: UIViewController {
 
   private let fetchFeedPublisher: PassthroughSubject<Void, Never> = .init()
   private let didDisplayFeedPublisher: PassthroughSubject<Void, Never> = .init()
+  private let refreshFeedPublisher: PassthroughSubject<Void, Never> = .init()
 
   private var feedCount: Int = 0
 
@@ -89,6 +91,7 @@ private extension HomeViewController {
     setupHierarchyAndConstraints()
     setNavigationItem()
     bind()
+    configureRefreshControl()
     fetchFeedPublisher.send()
   }
 
@@ -134,7 +137,8 @@ private extension HomeViewController {
     let output = viewModel.transform(
       input: HomeViewModelInput(
         requestFeedPublisher: fetchFeedPublisher.eraseToAnyPublisher(),
-        didDisplayFeed: didDisplayFeedPublisher.eraseToAnyPublisher()
+        didDisplayFeed: didDisplayFeedPublisher.eraseToAnyPublisher(),
+        refreshFeedPublisher: refreshFeedPublisher.eraseToAnyPublisher()
       )
     )
 
@@ -144,6 +148,8 @@ private extension HomeViewController {
         break
       case let .fetched(feed):
         self?.updateFeed(feed)
+      case let .refresh(feed):
+        self?.refreshFeed(feed)
       }
     }
     .store(in: &subscriptions)
@@ -154,6 +160,20 @@ private extension HomeViewController {
     navigationItem.leftBarButtonItem = titleBarButtonItem
   }
 
+  func refreshFeed(_ item: [FeedElement]) {
+    guard let dataSource else {
+      return
+    }
+    var snapshot = dataSource.snapshot()
+    snapshot.deleteAllItems()
+    snapshot.appendSections([0])
+    snapshot.appendItems(item)
+    DispatchQueue.main.async { [weak self] in
+      dataSource.apply(snapshot)
+      self?.feedListCollectionView.refreshControl?.endRefreshing()
+    }
+  }
+
   func updateFeed(_ item: [FeedElement]) {
     guard let dataSource else {
       return
@@ -168,35 +188,30 @@ private extension HomeViewController {
     feedCount = snapshot.numberOfItems
   }
 
+  func configureRefreshControl() {
+    // Add the refresh control to your UIScrollView object.
+    feedListCollectionView.refreshControl = UIRefreshControl()
+    feedListCollectionView.refreshControl?
+      .publisher(.valueChanged)
+      .sink { [weak self] _ in
+        self?.refreshFeedPublisher.send()
+      }
+      .store(in: &subscriptions)
+  }
+
   enum Constants {
     static let navigationTitleText = "홈"
   }
 
   enum Metrics {}
 }
 
-private extension HomeViewController {
-  static func makeFeedCollectionViewLayout() -> UICollectionViewCompositionalLayout {
-    let itemSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .fractionalHeight(1))
-    let item = NSCollectionLayoutItem(layoutSize: itemSize)
-    item.contentInsets = .init(top: 9, leading: 0, bottom: 9, trailing: 0)
-
-    let groupSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1), heightDimension: .estimated(455))
-    let group = NSCollectionLayoutGroup.vertical(layoutSize: groupSize, subitems: [item])
-
-    let section = NSCollectionLayoutSection(group: group)
-
-    return UICollectionViewCompositionalLayout(section: section)
-  }
-}
-
 // MARK: UICollectionViewDelegate
 
 extension HomeViewController: UICollectionViewDelegate {
   func collectionView(_: UICollectionView, willDisplay _: UICollectionViewCell, forItemAt indexPath: IndexPath) {
-    // 사용자가 아직 보지 않은 셀의 갯수
-    let toShowCellCount = (feedCount - 1) - indexPath.row
-    if toShowCellCount < 3 {
+    // 만약 셀이 모자르다면 요청을 보냄
+    if (feedCount - 1) - indexPath.row < 3 {
       fetchFeedPublisher.send()
     }
   }

iOS/Projects/Features/Home/Sources/Presntaion/HomeScene/ViewModel/HomeViewModel.swift

@@ -14,6 +14,7 @@ import Foundation
 public struct HomeViewModelInput {
   let requestFeedPublisher: AnyPublisher<Void, Never>
   let didDisplayFeed: AnyPublisher<Void, Never>
+  let refreshFeedPublisher: AnyPublisher<Void, Never>
 }
 
 public typealias HomeViewModelOutput = AnyPublisher<HomeState, Never>
@@ -23,6 +24,7 @@ public typealias HomeViewModelOutput = AnyPublisher<HomeState, Never>
 public enum HomeState {
   case idle
   case fetched(feed: [FeedElement])
+  case refresh(feed: [FeedElement])
 }
 
 // MARK: - HomeViewModelRepresentable
@@ -52,7 +54,7 @@ extension HomeViewModel: HomeViewModelRepresentable {
 
     let fetched: HomeViewModelOutput = input.requestFeedPublisher
       .flatMap { [useCase] _ in
-        useCase.fetchFeed()
+        return useCase.fetchFeed()
       }
       .map { feed in
         return HomeState.fetched(feed: feed)
@@ -65,9 +67,18 @@ extension HomeViewModel: HomeViewModelRepresentable {
       }
       .store(in: &subscriptions)
 
+    let refreshed: HomeViewModelOutput = input.refreshFeedPublisher
+      .flatMap { [useCase] _ in
+        return useCase.refreshFeed()
+      }
+      .map { feed in
+        return HomeState.refresh(feed: feed)
+      }
+      .eraseToAnyPublisher()
+
     let initialState: HomeViewModelOutput = Just(.idle).eraseToAnyPublisher()
 
-    return initialState.merge(with: fetched)
+    return initialState.merge(with: fetched, refreshed)
       .eraseToAnyPublisher()
   }
 }