Instruction file imported from fffonion/SlideShowWallpaper (.github/instructions/globalization.instructions.md). Copyright stays with the author.

Globalization & Localization

These rules apply to every feature and change involving user-facing text. They are not optional add-ons.

Rules

• All user-facing strings (UI text, error messages, tooltips) must come from .resw resource files — never hard-code them in XAML or C#.
• Resource file location: Strings/en-us/Resources.resw (default locale).
• Use x:Uid in XAML to bind controls to resource keys:

  <TextBlock x:Uid="WelcomeMessage" />

  With a matching .resw entry: WelcomeMessage.Text = "Welcome!"
• In code-behind / ViewModels, use the ResourceLoader:

  var loader = new Microsoft.Windows.ApplicationModel.Resources.ResourceLoader();
  string message = loader.GetString("ErrorFileNotFound");

• Format dates, numbers, and currencies using CultureInfo.CurrentCulture or DateTimeFormatter — never assume a specific regional format.
• Avoid concatenating translated strings — use format placeholders ({0}, {1}).
• Design UI layouts to accommodate text expansion (~30-40% longer for German vs. English).

Anti-patterns

• Hard-coded strings in .xaml or .cs files (e.g., Content="Save").
• Using string.Format with hard-coded ordinal assumptions.
• Fixed-width UI elements that clip translated text.

Validation

• Build & register the MSIX package — see Build, Run & Deploy in .github/agents/Agents.md.
• Check for hard-coded strings: search Content=" and Text=" in .xaml files — replace with x:Uid.

Verification Checklist

• All user-facing strings are in .resw resource files

Must Read & Research

Agent Rule: Before any localization-related change, you must fetch and review these references using fetch_webpage. Apply what you learn.