initial pre-viable version of watch app

Workouts/_ATTIC_/Cepo/EntityAddEditView.swift

@@ -0,0 +1,48 @@
+import SwiftUI
+import SwiftData
+
+struct EntityAddEditView<T: EditableEntity, Content: View>: View {
+    @Environment(\.dismiss) private var dismiss
+    @Environment(\.modelContext) private var modelContext
+
+    @State var model: T
+    private let content: (Binding<T>) -> Content
+
+    init(model: T, @ViewBuilder content: @escaping (Binding<T>) -> Content) {
+        _model = State(initialValue: model)
+        self.content = content
+    }
+
+    var body: some View {
+        NavigationStack {
+            Form {
+                content($model)
+            }
+            .toolbar {
+                ToolbarItem(placement: .navigationBarLeading) {
+                    Button("Cancel") {
+                        dismiss()
+                    }
+                }
+                
+                ToolbarItem(placement: .navigationBarTrailing) {
+                    Button("Save") {
+                        // If the model is not in a context, it's a new one.
+                        if model.modelContext == nil {
+                            modelContext.insert(model)
+                        }
+                        // The save is in a do-catch block to handle potential errors,
+                        // such as constraint violations.
+                        do {
+                            try modelContext.save()
+                            dismiss()
+                        } catch {
+                            // In a real app, you'd want to present this error to the user.
+                            print("Failed to save model: \(error.localizedDescription)")
+                        }
+                    }
+                }
+            }
+        }
+    }
+}