Merge pull request #91 from novoda/feature-rm-88-handle-server-error

Feature [RM88] Handle Server Error

Rick-and-Morty/CharacterRepository.swift

@@ -1,15 +1,15 @@
 import Foundation
 
 protocol CharacterRepositoryProtocol {
-    func getCharacters(completion: @escaping (([Character]) -> Void))
+    func getCharacters(completion: @escaping (([Character]) -> Void), fail: @escaping ((NSError?) -> Void))
 }
 
 final class CharacterRepository: CharacterRepositoryProtocol {
     private var characterPageURL: URL? = RickAndMortyService.baseURL.appendingPathComponent("character")
 
     private let rickAndMortyService: RickAndMortyServiceProtocol = RickAndMortyService()
 
-    func getCharacters(completion: @escaping (([Character]) -> Void)) {
+    func getCharacters(completion: @escaping (([Character]) -> Void), fail: @escaping ((NSError?) -> Void)) {
         if let url = characterPageURL {
             rickAndMortyService.fetchData(url: url) { (charactersResponse: CharacterResponse) in
                 if let nextURLString = charactersResponse.info.next {
@@ -21,9 +21,8 @@ final class CharacterRepository: CharacterRepositoryProtocol {
                 }
 
                 completion(charactersResponse.characters)
-            } error: { error in
-                print(error.debugDescription)
-                return
+            } fail: { (error: NSError?) in
+                fail(error)
             }
         }
     }

Rick-and-Morty/EpisodeRepository.swift

@@ -16,7 +16,7 @@ final class EpisodeRepository: EpisodeRepositoryProtocol {
                 rickAndMortyService.fetchData(url: url) { (episode: Episode) in
                     EpisodeRepository.cachedEpisodeNames[urlString] = episode
                     completion(episode)
-                } error: { error in
+                } fail: { error in
                     print(error.debugDescription)
                     return
                 }

Rick-and-Morty/Rick And Morty.xcodeproj/project.pbxproj

@@ -10,6 +10,7 @@
 		1711B39E26B1898100BE935B /* CharacterListView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1711B39D26B1898100BE935B /* CharacterListView.swift */; };
 		174655E826CBB74100A52819 /* EpisodeDetailView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 174655E726CBB74100A52819 /* EpisodeDetailView.swift */; };
 		174655EA26CBBD2300A52819 /* EpisodeDetailViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 174655E926CBBD2300A52819 /* EpisodeDetailViewModel.swift */; };
+		174878F626D4E3CA004293AB /* ErrorView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 174878F526D4E3CA004293AB /* ErrorView.swift */; };
 		174B064B26C6611D0080ADD0 /* RickAndMortyService.swift in Sources */ = {isa = PBXBuildFile; fileRef = 174B064A26C6611D0080ADD0 /* RickAndMortyService.swift */; };
 		174B064D26C661470080ADD0 /* RickAndMortyServiceProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 174B064C26C661470080ADD0 /* RickAndMortyServiceProtocol.swift */; };
 		174B065126C671580080ADD0 /* CharacterRepository.swift in Sources */ = {isa = PBXBuildFile; fileRef = 174B065026C671580080ADD0 /* CharacterRepository.swift */; };
@@ -41,6 +42,7 @@
 		1711B39D26B1898100BE935B /* CharacterListView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CharacterListView.swift; sourceTree = "<group>"; };
 		174655E726CBB74100A52819 /* EpisodeDetailView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EpisodeDetailView.swift; sourceTree = "<group>"; };
 		174655E926CBBD2300A52819 /* EpisodeDetailViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EpisodeDetailViewModel.swift; sourceTree = "<group>"; };
+		174878F526D4E3CA004293AB /* ErrorView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ErrorView.swift; sourceTree = "<group>"; };
 		174B064A26C6611D0080ADD0 /* RickAndMortyService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RickAndMortyService.swift; sourceTree = "<group>"; };
 		174B064C26C661470080ADD0 /* RickAndMortyServiceProtocol.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RickAndMortyServiceProtocol.swift; sourceTree = "<group>"; };
 		174B065026C671580080ADD0 /* CharacterRepository.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CharacterRepository.swift; sourceTree = "<group>"; };
@@ -140,6 +142,7 @@
 				1711B39D26B1898100BE935B /* CharacterListView.swift */,
 				17588BAE26C273BB008ECC31 /* CharacterCard.swift */,
 				174655E726CBB74100A52819 /* EpisodeDetailView.swift */,
+				174878F526D4E3CA004293AB /* ErrorView.swift */,
 				174941D126CD1216001AFD9A /* Utilities */,
 			);
 			path = Views;
@@ -308,6 +311,7 @@
 				B811686D1CFF1C9900301A0A /* AppDelegate.swift in Sources */,
 				174B065926C680850080ADD0 /* EpisodeRepository.swift in Sources */,
 				174655EA26CBBD2300A52819 /* EpisodeDetailViewModel.swift in Sources */,
+				174878F626D4E3CA004293AB /* ErrorView.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Rick-and-Morty/Rick And Morty/Services/RickAndMortyService.swift

@@ -3,7 +3,8 @@ import Foundation
 final class RickAndMortyService: RickAndMortyServiceProtocol {
     static let baseURL = URL(string: "https://rickandmortyapi.com/api")!
 
-    func fetchData<T:Decodable>(url: URL, success: @escaping (T) -> (), error: @escaping (Error?) -> ()) {
+    func fetchData<T:Decodable>(url: URL, success: @escaping (T) -> (), fail: @escaping (NSError?) -> ()) {
+
         let request = URLRequest(url: url)
 
         URLSession.shared.dataTask(with: request) { data, response, requestError in
@@ -16,15 +17,21 @@ final class RickAndMortyService: RickAndMortyServiceProtocol {
                         success(decodedData)
                     }
                 } catch let decodingError {
-                    DispatchQueue.main.async {
-                       error(decodingError)
+                    if let error = decodingError as NSError? {
+                        DispatchQueue.main.async {
+                            fail(error)
+                        }
+                    } else {
+                        print("Unknown Error: \(decodingError.localizedDescription)")
                     }
                 }
             } else {
-                if requestError != nil {
+                if let error = requestError as NSError? {
                     DispatchQueue.main.async {
-                        error(requestError)
+                        fail(error)
                     }
+                } else {
+                    print("Unknown Error: \(String(describing: requestError?.localizedDescription))")
                 }
             }
         }.resume()

Rick-and-Morty/Rick And Morty/Services/RickAndMortyServiceProtocol.swift

@@ -1,5 +1,5 @@
 import Foundation
 
 protocol RickAndMortyServiceProtocol {
-    func fetchData<T:Decodable>(url: URL, success: @escaping (T) -> (), error: @escaping (Error?) -> ())
+    func fetchData<T:Decodable>(url: URL, success: @escaping (T) -> (), fail: @escaping (NSError?) -> ())
 }

Rick-and-Morty/Rick And Morty/ViewModels/CharacterListViewModel.swift

@@ -5,7 +5,15 @@ final class CharacterListViewModel: ObservableObject {
 
     struct CharacterListViewState {
         let title: String = "Characters"
+        var errorMessage: String? = nil
         var characters: [Character]
+        var state: State = .doneLoading
+
+        enum State {
+            case loading
+            case doneLoading
+            case error
+        }
     }
 
     private let characterRepository: CharacterRepositoryProtocol = CharacterRepository()
@@ -16,11 +24,28 @@ final class CharacterListViewModel: ObservableObject {
     }
 
     func loadCharacters() {
-        characterRepository.getCharacters {
-            characters in
+        characterListViewState.state = .loading
+
+        characterRepository.getCharacters { characters in
+            self.characterListViewState.state = .doneLoading
+            self.characterListViewState.errorMessage = nil
+
             for character in characters {
                 self.characterListViewState.characters.append(character)
             }
+        } fail: { error in
+
+            self.characterListViewState.state = .error
+
+            if let error = error {
+                if error.code == 4864 {
+                    self.characterListViewState.errorMessage = "Wubba Lubba Dub Dub! There was a problem loading the characters."
+                } else {
+                    self.characterListViewState.errorMessage = error.localizedDescription
+                }
+
+                self.characterListViewState.errorMessage?.append(" Tap the refresh button to try again..")
+            }
         }
     }
 

Rick-and-Morty/Rick And Morty/Views/CharacterListView.swift

@@ -5,12 +5,21 @@ struct CharacterListView: View {
 
     var body: some View {
         NavigationView {
-            List(viewModel.characterListViewState.characters, id: \.id) { character in
-                CharacterCard(viewModel: CharacterCardViewModel(character: character))
-                    .onAppear(perform: {
-                        viewModel.loadIfNeeded(characterID: character.id)
-                    })
+            ZStack {
+                List(viewModel.characterListViewState.characters, id: \.id) { character in
+                    CharacterCard(viewModel: CharacterCardViewModel(character: character))
+                        .onAppear(perform: {
+                            viewModel.loadIfNeeded(characterID: character.id)
+                        })
+                }
+
+                if viewModel.characterListViewState.state == .error {
+                    ErrorView(errorMessage: viewModel.characterListViewState.errorMessage, refreshAction: viewModel.loadCharacters)
+                } else if viewModel.characterListViewState.state == .loading {
+                    ProgressView()
+                }
             }
+            .listStyle(PlainListStyle())
             .navigationTitle(viewModel.characterListViewState.title)
         }
     }

Rick-and-Morty/Rick And Morty/Views/ErrorView.swift

@@ -0,0 +1,37 @@
+//
+//  ErrorView.swift
+//  Rick And Morty
+//
+//  Created by Scottie Gray on 2021-08-24.
+//  Copyright © 2021 Novoda. All rights reserved.
+//
+
+import SwiftUI
+
+struct ErrorView: View {
+    let errorMessage: String?
+    let refreshAction: () -> ()
+
+    var body: some View {
+        if let error = errorMessage {
+            VStack {
+                Text(error)
+                    .foregroundColor(.gray)
+                    .multilineTextAlignment(.center)
+                    .padding()
+                Button(action: refreshAction, label: {
+                    Image(systemName: "arrow.clockwise")
+                        .resizable()
+                        .frame(width: 30, height: 30, alignment: /*@START_MENU_TOKEN@*/.center/*@END_MENU_TOKEN@*/)
+                })
+            }
+        }
+    }
+}
+
+struct ErrorView_Previews: PreviewProvider {
+    static var previews: some View {
+        ErrorView(errorMessage: "Wubba Lubba Dub Dub! There was a problem loading. Tap the button to try again.", refreshAction: {})
+
+    }
+}