✨ [feat] #36 네비게이션 바 뒤로가기 버튼 조건 추가 및 alert 띄우기 구현

- 뒤로가기 버튼 클릭시 그냥 dismiss 하는 방식과 alert 띄워 액션 처리하는 방식을 모두 지원하도록 NavigationBar 컴포넌트 수정

Author: pearhyunjin

FunForYou/FunForYou/Sources/Common/DesignSystem/NavigationBar.swift

@@ -10,19 +10,22 @@ import SwiftUI
 /// 공통 디자인 컴포넌트 - Navigation Bar
 /// - 뒤로가기 버튼만  - title: nil, style: .back
 /// - 뒤로가기 버튼 + 타이틀 - title: "바제목", style: .backTitle
-/// - 뒤로가기 버튼 + 타이틀 + 활성버튼 - title: "바제목", style: .backTitleButton(title: "버튼이름", isEnabled: true, action: { })
-/// - 뒤로가기 버튼 + 타이틀 + 비활성버튼 - title: "바제목", style: .backTitleButton(title: "버튼이름", isEnabled: false, action: { })
+/// - 뒤로가기 버튼 + 타이틀 + 활성버튼 - title: "바제목", style: .backTitleButton(title: "버튼이름", isEnabled: true, action: { }), onBack: { }
+/// - 뒤로가기 버튼 + 타이틀 + 비활성버튼 - title: "바제목", style: .backTitleButton(title: "버튼이름", isEnabled: false, action: { }), onBack: { }
 struct NavigationBar: View {
     @Environment(\.dismiss) private var dismiss
 
     let title: String?
     let style: NavigationStyleType
+    var onBack: (() -> Void)?
 
     init(title: String? = nil,
-         style: NavigationStyleType
+         style: NavigationStyleType,
+         onBack: (() -> Void)? = nil
     ) {
         self.title = title
         self.style = style
+        self.onBack = onBack
     }
 
     var body: some View {
@@ -36,7 +39,7 @@ struct NavigationBar: View {
 
                 HStack {
                     Button(action: {
-                        dismiss()
+                        onBack?()
                     }, label: {
                         Image(systemName: "chevron.backward")
                             .resizable()

FunForYou/FunForYou/Sources/Common/DesignSystem/PrimaryAlert.swift

@@ -15,7 +15,7 @@ struct PrimaryAlert: View {
     let onPrimary: () -> Void
     let onSecondary: () -> Void
 
-    @State private var isVisible = false
+    @Binding var isVisible: Bool
 
     var body: some View {
         ZStack {
@@ -84,13 +84,15 @@ struct PrimaryAlert: View {
 }
 
 #Preview {
+    @Previewable @State var searchText = true
     PrimaryAlert(
         style:.basic,
         onPrimary: {
             print("아니요, 계속 쓸래요")
         },
         onSecondary: {
             print("네, 이전으로 돌아갈게요")
-        }
+        },
+        isVisible: $searchText
     )
 }

FunForYou/FunForYou/Sources/Presentation/Daily/DailyWriting/DailyWritingView.swift

@@ -10,6 +10,7 @@ import SwiftUI
 struct DailyWritingView: View {
     @StateObject var viewModel: DailyWritingViewModel
     @Environment(\.modelContext) private var context
+    @Environment(\.dismiss) private var dismiss
 
     init(daily: Daily?, coordinator: Coordinator) {
         _viewModel = StateObject(wrappedValue: DailyWritingViewModel(daily: daily, coordinator: coordinator))
@@ -22,9 +23,15 @@ struct DailyWritingView: View {
                 style: .backTitleButton(
                     title: "저장하기",
                     isEnabled: viewModel.state.isSaveEnabled
-                ) {
-                viewModel.action(.saveDailyInspiration(context))
-            })
+                ) { viewModel.action(.saveDailyInspiration(context)) },
+                onBack: {
+                    if viewModel.state.isSaveEnabled {
+                        viewModel.state.isShowAlert = true
+                    } else {
+                        dismiss()
+                    }
+                }
+            )
 
             DailyWritingContentView(
                 dailyTitle: $viewModel.state.dailyTitle,
@@ -36,6 +43,20 @@ struct DailyWritingView: View {
         .sheet(isPresented: $viewModel.state.isShowImagePicker) {
             PhotoPicker(selectedImage: $viewModel.state.selectedImage)
         }
+        .overlay {
+            if viewModel.state.isShowAlert {
+                PrimaryAlert(
+                    style: .deleteInspiration,
+                    onPrimary: {
+                        dismiss()
+                    },
+                    onSecondary: {
+                        viewModel.state.isShowAlert = false
+                    },
+                    isVisible: $viewModel.state.isShowAlert
+                )
+            }
+        }
         .hideKeyboardOnTap()
     }
 }

FunForYou/FunForYou/Sources/Presentation/Daily/DailyWriting/DailyWritingViewModel.swift

@@ -17,6 +17,7 @@ final class DailyWritingViewModel: ViewModelable {
         var dailyContent: String = ""
         var selectedImage: UIImage?
         var isShowImagePicker: Bool = false
+        var isShowAlert: Bool = false
 
         var isSaveEnabled: Bool {
             !dailyTitle.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty ||