💾 Implement (local) persistence

Graduator/Graduator.xcodeproj/project.pbxproj

@@ -19,6 +19,7 @@
 		EC242B882A1FC605006FE760 /* NoGradesInfo.swift in Sources */ = {isa = PBXBuildFile; fileRef = EC242B872A1FC605006FE760 /* NoGradesInfo.swift */; };
 		EC242B8A2A1FCECA006FE760 /* AverageBlockView.swift in Sources */ = {isa = PBXBuildFile; fileRef = EC242B892A1FCECA006FE760 /* AverageBlockView.swift */; };
 		EC5FE5A52A20882F0028AA5F /* Formatters.swift in Sources */ = {isa = PBXBuildFile; fileRef = EC5FE5A42A20882F0028AA5F /* Formatters.swift */; };
+		EC8BAD162A3465230062226B /* UnitsStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = EC8BAD152A3465230062226B /* UnitsStore.swift */; };
 		ECB2FFCE2A23C4A700FF9F91 /* SubjectFormView.swift in Sources */ = {isa = PBXBuildFile; fileRef = ECB2FFCD2A23C4A700FF9F91 /* SubjectFormView.swift */; };
 		ECB2FFD02A23C4B700FF9F91 /* SubjectFormVM.swift in Sources */ = {isa = PBXBuildFile; fileRef = ECB2FFCF2A23C4B700FF9F91 /* SubjectFormVM.swift */; };
 		ECC581D22A1D085B006C55EF /* GraduatorApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = ECC581D12A1D085B006C55EF /* GraduatorApp.swift */; };
@@ -41,6 +42,7 @@
 		EC242B872A1FC605006FE760 /* NoGradesInfo.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NoGradesInfo.swift; sourceTree = "<group>"; };
 		EC242B892A1FCECA006FE760 /* AverageBlockView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AverageBlockView.swift; sourceTree = "<group>"; };
 		EC5FE5A42A20882F0028AA5F /* Formatters.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Formatters.swift; sourceTree = "<group>"; };
+		EC8BAD152A3465230062226B /* UnitsStore.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = UnitsStore.swift; sourceTree = "<group>"; };
 		ECB2FFCD2A23C4A700FF9F91 /* SubjectFormView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SubjectFormView.swift; sourceTree = "<group>"; };
 		ECB2FFCF2A23C4B700FF9F91 /* SubjectFormVM.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SubjectFormVM.swift; sourceTree = "<group>"; };
 		ECC581CE2A1D085B006C55EF /* Graduator.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Graduator.app; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -108,6 +110,15 @@
 			path = Utils;
 			sourceTree = "<group>";
 		};
+		EC8BAD142A34650D0062226B /* Data */ = {
+			isa = PBXGroup;
+			children = (
+				EC242B822A1FAA9B006FE760 /* Stub.swift */,
+				EC8BAD152A3465230062226B /* UnitsStore.swift */,
+			);
+			path = Data;
+			sourceTree = "<group>";
+		};
 		ECB2FFCC2A23C49500FF9F91 /* Forms */ = {
 			isa = PBXGroup;
 			children = (
@@ -135,12 +146,12 @@
 		ECC581D02A1D085B006C55EF /* Graduator */ = {
 			isa = PBXGroup;
 			children = (
+				EC8BAD142A34650D0062226B /* Data */,
 				ECE6E3C02A1F80F6004FE471 /* Model */,
 				ECC581DF2A1D08C3006C55EF /* ViewModel */,
 				EC242B6F2A1F8260006FE760 /* View */,
 				ECC581D12A1D085B006C55EF /* GraduatorApp.swift */,
 				EC242B702A1F8283006FE760 /* MainView.swift */,
-				EC242B822A1FAA9B006FE760 /* Stub.swift */,
 				ECC581D52A1D085C006C55EF /* Assets.xcassets */,
 				ECC581D72A1D085C006C55EF /* Preview Content */,
 			);
@@ -251,6 +262,7 @@
 				EC242B6E2A1F81CC006FE760 /* UnitsManager.swift in Sources */,
 				ECC581E52A1D0C44006C55EF /* UnitVM.swift in Sources */,
 				EC5FE5A52A20882F0028AA5F /* Formatters.swift in Sources */,
+				EC8BAD162A3465230062226B /* UnitsStore.swift in Sources */,
 				EC242B7F2A1F83BF006FE760 /* UnitsManagerVM.swift in Sources */,
 				EC242B7B2A1F838C006FE760 /* UnitViewCell.swift in Sources */,
 				EC242B6C2A1F81AE006FE760 /* Subject.swift in Sources */,

Graduator/Graduator/Data/UnitsStore.swift

@@ -0,0 +1,54 @@
+//
+//  UnitsStore.swift
+//  Graduator
+//
+//  Created by etudiant on 2023-06-10.
+//
+
+import SwiftUI
+
+
+class UnitsStore: ObservableObject {
+    
+    var units: [Unit] = []
+    
+    private static func fileURL() throws -> URL {
+        try FileManager.default.url(
+            for: .documentDirectory,
+            in: .userDomainMask,
+            appropriateFor: nil,
+            create: false
+        ).appendingPathComponent("units.data")
+    }
+    
+    func load() async throws -> [Unit] {
+        
+        let task = Task<[Unit], Error> {
+            let fileURL = try Self.fileURL()
+            let data = try? Data(contentsOf: fileURL)
+            var units: [Unit] = []
+            if (data == nil || data!.isEmpty) {
+                units = Stub.units
+            }
+            else if (data != nil) {
+                units = try JSONDecoder().decode([Unit].self, from: data!)
+            }
+            return units
+        }
+        
+        self.units = try await task.value
+        return self.units
+    }
+    
+    func save(units: [Unit]) async throws {
+        
+        let task = Task {
+            let data = try JSONEncoder().encode(units)
+            let outfile = try Self.fileURL()
+            try data.write(to: outfile)
+        }
+        
+        _ = try await task.value
+    }
+    
+}

Graduator/Graduator/GraduatorApp.swift

@@ -14,6 +14,13 @@ struct GraduatorApp: App {
     var body: some Scene {
         WindowGroup {
             MainView(unitsManagerVM: unitsManagerVM)
+                .task {
+                    do {
+                        try await unitsManagerVM.load()
+                    } catch {
+                        fatalError(error.localizedDescription)
+                    }
+                }
                 .environmentObject(unitsManagerVM)
         }
     }

Graduator/Graduator/Model/Subject.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct Subject : Identifiable {
+struct Subject : Identifiable, Codable {
     let id: UUID
     var name: String
     var weight: Int

Graduator/Graduator/Model/Unit.swift

@@ -7,7 +7,7 @@
 
 import Foundation
 
-struct Unit : Identifiable {
+struct Unit : Identifiable, Codable {
     let id: UUID
     var name: String
     var weight: Int
@@ -15,6 +15,7 @@ struct Unit : Identifiable {
     var code: Int
     var subjects: [Subject]
     
+    // FIXME DRY
     func getAverage() -> Double? {
         var totalWeight = 0
         var weightedSum = 0.0

Graduator/Graduator/Model/UnitsManager.swift

@@ -10,6 +10,32 @@ import Foundation
 struct UnitsManager {
     
     var units: [Unit]
+    private var store = UnitsStore()
+
+    public init(units: [Unit] = [], store: UnitsStore = UnitsStore()) {
+        self.units = units
+        self.store = store
+    }
+    
+    mutating func load() async throws {
+        print("Loading...")
+        do {
+            self.units = try await store.load()
+            print("Units loaded")
+        } catch {
+            print("ERROR: Failed to load...")
+        }
+    }
+    
+    func save() async throws {
+        print("Saving...")
+        do {
+            try await store.save(units: units)
+            print("Units saved")
+        } catch {
+            print("ERROR: Failed to save...")
+        }
+    }
     
     func getTotalAverage() -> Double? {
         return getAverage(units: units)
@@ -19,6 +45,7 @@ struct UnitsManager {
         return getAverage(units: units.filter { $0.isProfessional })
     }
     
+    // FIXME DRY
     func getAverage(units: [Unit]) -> Double? {
         var totalWeight = 0
         var weightedSum = 0.0

Graduator/Graduator/View/Cells/SubjectViewCell.swift

@@ -17,6 +17,9 @@ struct SubjectViewCell: View {
     var body: some View {
         HStack {
             VStack {
+                // FIXME (later, maybe) when getting updated from the UnitView, these two changes are persisted right away instead of waiting for user
+                // to confirm changes. Or is it rather that we were updating these fields, and then changing the grade, thus calling
+                // unitsManagerVM.updateUnit(unitVM) ? If so, how to even fix that?
                 HStack {
                     TextField("", text: $subjectVM.model.name)
                         .disabled(!unitsManagerVM.isAllEditable)
@@ -33,9 +36,15 @@ struct SubjectViewCell: View {
                                 .frame(width: 40)
                                 .onChange(of: isGradeEditable) { value in
                                     if !value {
+                                        Task {
+                                            do {
                                                 subjectVM.onEdited()
                                                 unitVM.updateSubject(subjectVM)
-                                        unitsManagerVM.updateUnit(unitVM)
+                                                try await unitsManagerVM.updateUnit(unitVM)
+                                            } catch {
+                                                print("Failed to update grade: \(error)")
+                                            }
+                                        }
                                     }
                                 }
                             Image(systemName: isGradeEditable ? "checkmark" : "lock.open")

Graduator/Graduator/View/Views/UnitView.swift

@@ -19,7 +19,6 @@ struct UnitView: View {
         guard let index = offsets.first else { return }
         let subjectVMToDelete = unitVM.SubjectsVM[index]
         unitVM.deleteSubject(subjectVMToDelete)
-        unitsManagerVM.updateUnit(unitVM)
     }
     
     var body: some View {
@@ -83,10 +82,16 @@ struct UnitView: View {
                         Text("Annuler")
                     }
                     Button(action: {
+                        Task {
+                            do {
                                 unitsManagerVM.isAllEditable.toggle()
                                 unitVM.onEdited()
                                 unitVM.updateAllSubjects()
-                        unitsManagerVM.updateUnit(unitVM)
+                                try await unitsManagerVM.updateUnit(unitVM)
+                            } catch {
+                                print("Failed to update unit: \(error)")
+                            }
+                        }
                     }) {
                         Text("OK")
                     }
@@ -107,9 +112,15 @@ struct UnitView: View {
                             leading: Button("Annuler") { showingForm = false },
                             trailing: Button("Enregistrer") {
                                 if let newSubject = formVM.createSubject() {
+                                    Task {
+                                        do {
                                             unitVM.addSubject(newSubject)
-                                    unitsManagerVM.updateUnit(unitVM)
+                                            try await unitsManagerVM.updateUnit(unitVM)
                                             showingForm = false
+                                        } catch {
+                                            print("Failed to create unit: \(error)")
+                                        }
+                                    }
                                 } else {
                                     showAlert = true
                                 }

Graduator/Graduator/ViewModel/UnitVM.swift

@@ -60,7 +60,7 @@ class UnitVM : ObservableObject, Identifiable {
     init(unit: Unit) {
         original = unit
         model = original.data
-        subjectsVM = unit.subjects.map { SubjectVM(subject: $0) }
+        subjectsVM = original.subjects.map { SubjectVM(subject: $0) }
     }
     
     convenience init() {

Graduator/Graduator/ViewModel/UnitsManagerVM.swift

@@ -54,18 +54,41 @@ class UnitsManagerVM : ObservableObject {
     init(unitsManager: UnitsManager) {
         original = unitsManager
         model = original.data
-        unitsVM = unitsManager.units.map { UnitVM(unit: $0) }
+        unitsVM = original.units.map { UnitVM(unit: $0) }
     }
     
     convenience init() {
         self.init(unitsManager: UnitsManager(units: []))
     }
     
-    func updateUnit(_ unitVM: UnitVM) {
+    func load() async throws {
+        print("Loading VM...")
+        do {
+            try await original.load()
+            DispatchQueue.main.async {
+                self.model = self.original.data
+                self.unitsVM = self.original.units.map { UnitVM(unit: $0) }
+                print("VM loaded")
+            }
+        } catch {
+            print("ERROR: Failed to load VM...")
+        }
+    }
+    
+    func updateUnit(_ unitVM: UnitVM) async throws {
         guard let index = unitsVM.firstIndex(where: { $0.id == unitVM.id }) else { return }
         let updatedUnit = unitsVM[index].model
         original.units[index].update(from: updatedUnit)
-        model = original.data
+        print("Saving VM...")
+        do {
+            try await original.save()
+            print("VM saved")
+            DispatchQueue.main.async {
+                self.model = self.original.data
+            }
+        } catch {
+            print("ERROR: Failed to save VM...")
+        }
     }
     
     var TotalAverage: Double? {