Generate first tag pages

CHDataManagement/Views/Pages/PageDetailView.swift

@@ -14,8 +14,22 @@ struct PageDetailView: View {
     @State
     private var isGeneratingWebsite = false
 
+    @State
+    private var newId: String
+
     init(page: Page) {
         self.page = page
+        self.newId = page.id
+    }
+
+    private let allowedCharactersInPostId = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "-")).inverted
+
+    private var idExists: Bool {
+        page.content.pages.contains { $0.id == newId }
+    }
+
+    private var containsInvalidCharacters: Bool {
+        newId.rangeOfCharacter(from: allowedCharactersInPostId) != nil
     }
 
     var body: some View {
@@ -25,11 +39,13 @@ struct PageDetailView: View {
                     Text("Generate")
                 }
                 .disabled(isGeneratingWebsite)
-                Text("ID")
-                    .font(.headline)
-                TextField("", text: $page.id)
-                    .textFieldStyle(.roundedBorder)
-                    .padding(.bottom)
+                HStack {
+                    TextField("", text: $newId)
+                        .textFieldStyle(.roundedBorder)
+                    Button("Update", action: setNewId)
+                    .disabled(newId.isEmpty || containsInvalidCharacters || idExists)
+                }
+                .padding(.bottom)
 
                 HStack {
                     Text("Draft")
@@ -102,12 +118,20 @@ struct PageDetailView: View {
             }
         }
     }
+
+    private func setNewId() {
+        guard page.update(id: newId) else {
+            newId = page.id
+            return
+        }
+        page.id = newId
+    }
 }
 
 extension PageDetailView: MainContentView {
 
     init(item: Page) {
-        self.page = item
+        self.init(page: item)
     }
 
     static let itemDescription = "a page"