add minimal generalized main/detail view

WorkoutsPlus/ItemLibrary.swift

@@ -0,0 +1,100 @@
+//
+//  ContentView.swift
+//  WorkoutsPlus
+//
+//  Created by Felix Förtsch on 10.08.24.
+//
+
+import SwiftUI
+import SwiftData
+
+struct ItemLibrary: View {
+		@Environment(\.modelContext) private var modelContext
+		@Query private var items: [Item]
+		
+		@State private var isPresentingNewItemSheet = false
+		
+		let initialDataSet = [
+				"Pull-up",
+				"Push-up",
+				"Dips",
+				"Rows",
+				"Split Squat"
+		]
+		
+		var body: some View {
+				NavigationView {
+						List {
+								ForEach(items) { item in
+										NavigationLink(destination: ItemDetailsView(item: item)) {
+												Text(item.name)
+										}
+								}
+								.onDelete(perform: deleteItem)
+						}
+						.onAppear {
+								if items.isEmpty {
+										loadInitialData(exercises: initialDataSet)
+								}
+						}
+						.toolbar {
+								ToolbarItem(placement: .navigationBarTrailing) {
+										Button {
+												createNewItem()
+										} label: {
+												Label("Add Exercise", systemImage: "plus")
+										}
+								}
+						}
+						.sheet(isPresented: $isPresentingNewItemSheet) {
+								let newItem = Item(name: "")
+								NavigationView {
+										ItemDetailsView(item: newItem, isPresentedAsSheet: true)
+												.onDisappear {
+														if !newItem.name.isEmpty {
+																saveItem(item: newItem)
+														}
+												}
+								}
+						}
+				}
+		}
+		
+		private func createNewItem() {
+				isPresentingNewItemSheet = true
+		}
+		
+		private func saveItem(item: Item) {
+				modelContext.insert(item)
+				try? modelContext.save()
+		}
+		
+		private func deleteItem(offsets: IndexSet) {
+				withAnimation {
+						for index in offsets {
+								modelContext.delete(items[index])
+						}
+						try? modelContext.save()
+				}
+		}
+		
+		private func loadInitialData(exercises: [String]) {
+				var items: [Item] = []
+				
+				for exercise in exercises {
+						let item = Item(name: exercise)
+						items.append(item)
+				}
+				
+				for item in items {
+						modelContext.insert(item)
+				}
+				
+				try? modelContext.save()
+		}
+}
+
+#Preview {
+		ItemLibrary()
+				.modelContainer(for: Item.self, inMemory: true)
+}