fix: T1260228 - Theme Switcher for Blazor - Applied and selected themes are incorrect when the Boostrap Default Dark theme is selected

morozov · morozov · commit 0ce213a4d0d1 · 2025-01-14T10:34:47.000+02:00
diff --git a/CS/switcher/switcher/App.razor b/CS/switcher/switcher/App.razor
@@ -14,7 +14,7 @@
 }
 
 <!DOCTYPE html>
-<html lang="en" >
+<html lang="en" data-bs-theme="@Themes.ActiveTheme.BootstrapThemeMode">
 <head>
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
@@ -38,7 +38,7 @@
 </head>
 <body>
     <div id="switcher-container" data-permanent></div>
-    <Routes></Routes>   
+    <Routes></Routes>
     <script src="_framework/blazor.web.js"></script>
 </body>
 
diff --git a/CS/switcher/switcher/ThemeSwitcher/ThemeSwitcher.razor b/CS/switcher/switcher/ThemeSwitcher/ThemeSwitcher.razor
@@ -1,4 +1,7 @@
-﻿@inject ThemeService Themes
+﻿@implements IDisposable
+@inject ThemeService Themes
+@inject PersistentComponentState ApplicationState
+
 @rendermode InteractiveServer
 <ThemeJsChangeDispatcher InitialThemeName="blazor-berry"></ThemeJsChangeDispatcher>
 <div class="@GetHeaderContainerCss()">
@@ -16,6 +19,7 @@
 @code {
     string _themeName;
     bool _themeSwitcherShown;
+    PersistingComponentStateSubscription _persistingSubscription;
 
     protected string ThemeName {
         get { return _themeName; }
@@ -39,7 +43,11 @@
         }
     }
     protected override void OnInitialized() {
-        ThemeName = Themes.ActiveTheme?.Name ?? string.Empty;
+        _persistingSubscription = ApplicationState.RegisterOnPersisting(PersistData);
+        if (ApplicationState.TryTakeFromJson<string>("ThemeName", out var themeName) && themeName != null)
+            ThemeName = themeName;
+        else
+            ThemeName = Themes.ActiveTheme?.Name ?? string.Empty;
     }
     void ToggleThemeSwitcherPanel() {
         ThemeSwitcherShown = !ThemeSwitcherShown;
@@ -54,4 +62,11 @@
             cssClasses.Add("theme-external");
         return string.Join(" ", cssClasses);
     }
+    Task PersistData() {
+        ApplicationState.PersistAsJson("ThemeName", ThemeName);
+        return Task.CompletedTask;
+    }
+    void IDisposable.Dispose() {
+        _persistingSubscription.Dispose();
+    }
 }
