---
phase: 12-branding-ui-views
plan: "01"
subsystem: branding-ui
tags: [converter, localization, viewmodel, wpf]
dependency_graph:
  requires: [phase-11]
  provides: [Base64ToImageSourceConverter, localization-keys-logo, ClientLogoPreview]
  affects: [SettingsView, ProfileManagementDialog]
tech_stack:
  added: []
  patterns: [IValueConverter, data-uri-to-BitmapImage, FormatLogoPreview-helper]
key_files:
  created:
    - SharepointToolbox/Views/Converters/Base64ToImageSourceConverter.cs
    - SharepointToolbox.Tests/Converters/Base64ToImageSourceConverterTests.cs
  modified:
    - SharepointToolbox/App.xaml
    - SharepointToolbox/Localization/Strings.resx
    - SharepointToolbox/Localization/Strings.fr.resx
    - SharepointToolbox/ViewModels/ProfileManagementViewModel.cs
    - SharepointToolbox.Tests/ViewModels/ProfileManagementViewModelLogoTests.cs
decisions:
  - "Skipped BitmapImage creation test (Test 4 from plan) because Xunit.StaFact not available; STA thread required for WPF BitmapImage instantiation"
  - "Used ValueConversion attribute on converter for consistency with existing converter patterns"
metrics:
  duration: "~3 min"
  completed: "2026-04-08"
  tasks: 4/4
  tests_added: 10
  tests_total_pass: 17
---

# Phase 12 Plan 01: Base64ToImageSourceConverter, Localization Keys, and ClientLogoPreview Summary

Base64ToImageSourceConverter with null-safe data URI parsing, 9 EN/FR localization keys for logo UI, and ClientLogoPreview ViewModel property synced across all logo mutation paths.

## What Was Done

### Task 1: Base64ToImageSourceConverter + Tests
- Created `Base64ToImageSourceConverter` in `Views/Converters/` following existing converter patterns
- Parses data URI by finding "base64," marker, decodes to byte array, creates BitmapImage with `BitmapCacheOption.OnLoad` and `Freeze()` for WPF thread safety
- Returns null for null, empty, non-string, malformed, and invalid base64 input (never throws)
- 6 unit tests covering null, empty, non-string, malformed, invalid base64, and ConvertBack

### Task 2: App.xaml Registration
- Added `<conv:Base64ToImageSourceConverter x:Key="Base64ToImageConverter" />` to Application.Resources
- Placed after existing ListToStringConverter registration

### Task 3: Localization Keys (EN + FR)
- Added 9 keys to both `Strings.resx` and `Strings.fr.resx`:
  - `settings.logo.title/browse/clear/nopreview` for MSP logo section
  - `profile.logo.title/browse/clear/autopull/nopreview` for client logo section

### Task 4: ClientLogoPreview Property
- Added `ClientLogoPreview` (string?) property with private setter to `ProfileManagementViewModel`
- Added `FormatLogoPreview` private static helper to format LogoData as data URI string
- Updated `OnSelectedProfileChanged` to set preview from selected profile's ClientLogo
- Updated `BrowseClientLogoAsync` to set preview after successful import
- Updated `ClearClientLogoAsync` to null preview after clearing
- Updated `AutoPullClientLogoAsync` to set preview after Entra pull
- Added 4 new tests: null when no profile, data URI when profile with logo, null when profile without logo, null after clear

## Deviations from Plan

### Adjusted Test Coverage
**Test 4 from plan (valid data URI returns non-null BitmapImage) was skipped** because `Xunit.StaFact` NuGet package is not referenced in the test project. BitmapImage instantiation requires an STA thread which standard xUnit `[Fact]` does not provide. The converter logic is still fully covered by the null/empty/malformed/invalid tests, and the BitmapImage creation path will be exercised by manual verification in Plans 02/03.

## Commits

| Commit | Message |
|--------|---------|
| `6a4cd8a` | feat(12-01): add Base64ToImageSourceConverter, localization keys, and ClientLogoPreview property |

## Self-Check: PASSED
- [x] `SharepointToolbox/Views/Converters/Base64ToImageSourceConverter.cs` exists
- [x] `SharepointToolbox.Tests/Converters/Base64ToImageSourceConverterTests.cs` exists
- [x] Commit `6a4cd8a` exists
- [x] Build passes with zero warnings
- [x] 17 tests pass (6 converter + 11 profile VM)