External files, improve page generation

CHDataManagement/Views/Pages/LocalizedPageDetailView.swift

@@ -4,22 +4,47 @@ import SFSafeSymbols
 struct LocalizedPageDetailView: View {
 
     @ObservedObject
-    private var item: LocalizedPage
+    private var page: LocalizedPage
 
     init(page: LocalizedPage, showImagePicker: Bool = false) {
-        self.item = page
+        self.page = page
         self.showImagePicker = showImagePicker
+        self.newUrlString = page.urlString
     }
 
     @State
     private var showImagePicker = false
 
+    @State
+    private var newUrlString: String
+
+    private let allowedCharactersInPostId = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "-")).inverted
+
+    private var idExists: Bool {
+        page.content.pages.contains {
+            $0.german.urlString == newUrlString
+            || $0.english.urlString == newUrlString
+        }
+    }
+
+    private var containsInvalidCharacters: Bool {
+        newUrlString.rangeOfCharacter(from: allowedCharactersInPostId) != nil
+    }
+
     var body: some View {
         VStack(alignment: .leading) {
+            HStack {
+                TextField("", text: $newUrlString)
+                    .textFieldStyle(.roundedBorder)
+                Button("Update", action: setNewId)
+                .disabled(newUrlString.isEmpty || containsInvalidCharacters || idExists)
+            }
+            .padding(.bottom)
+
             Text("Link Preview Title")
                 .font(.headline)
-            OptionalTextField("", text: $item.linkPreviewTitle,
-                              prompt: item.title)
+            OptionalTextField("", text: $page.linkPreviewTitle,
+                              prompt: page.title)
                 .textFieldStyle(.roundedBorder)
             .padding(.bottom)
 
@@ -35,13 +60,13 @@ struct LocalizedPageDetailView: View {
                 IconButton(symbol: .trashCircleFill,
                            size: 22,
                            color: .red) {
-                    item.linkPreviewImage = nil
-                }.disabled(item.linkPreviewImage == nil)
+                    page.linkPreviewImage = nil
+                }.disabled(page.linkPreviewImage == nil)
                 Spacer()
             }
 
             .buttonStyle(.plain)
-            if let image = item.linkPreviewImage {
+            if let image = page.linkPreviewImage {
                 image.imageToDisplay
                     .resizable()
                     .aspectRatio(contentMode: .fit)
@@ -52,16 +77,20 @@ struct LocalizedPageDetailView: View {
             Text("Link Preview Description")
                 .font(.headline)
                 .padding(.top)
-            OptionalDescriptionField(text: $item.linkPreviewDescription)
+            OptionalDescriptionField(text: $page.linkPreviewDescription)
                 .textFieldStyle(.roundedBorder)
                 .padding(.bottom)
         }
         .sheet(isPresented: $showImagePicker) {
             ImagePickerView(showImagePicker: $showImagePicker) { image in
-                item.linkPreviewImage = image
+                page.linkPreviewImage = image
             }
         }
     }
+
+    private func setNewId() {
+        page.urlString = newUrlString
+    }
 }
 
 #Preview {