Improving how dependencies for themes are handled: enabling dependencies (modules) for themes too, handling this also when themes are just previewed and disabling themes when their dependencies are disabled.

Fixes the tightly connected following issues: #4336, #5004, #4667

src/Orchard.Web/Modules/Orchard.Themes/Controllers/AdminController.cs

@@ -37,6 +37,8 @@ namespace Orchard.Themes.Controllers {
         private readonly IReportsCoordinator _reportsCoordinator;
         private readonly ShellSettings _shellSettings;
 
+        private const string AlreadyEnabledFeatures = "Orchard.Themes.AlreadyEnabledFeatures";
+
         public AdminController(
             IEnumerable<IExtensionDisplayEventHandler> extensionDisplayEventHandlers,
             IOrchardServices services,
@@ -136,8 +138,11 @@ namespace Orchard.Themes.Controllers {
 
                 Services.Notifier.Error(T("Theme {0} was not found", themeId));
             } else {
+                var alreadyEnabledFeatures = GetEnabledFeatures();
                 _themeService.EnableThemeFeatures(themeId);
                 _previewTheme.SetPreviewTheme(themeId);
+                alreadyEnabledFeatures.Except(new[] { themeId });
+                TempData[AlreadyEnabledFeatures] = alreadyEnabledFeatures;
             }
 
             return this.RedirectLocal(returnUrl, "~/");
@@ -165,6 +170,18 @@ namespace Orchard.Themes.Controllers {
             if (!Services.Authorizer.Authorize(Permissions.ApplyTheme, T("Couldn't preview the current theme")))
                 return new HttpUnauthorizedResult();
 
+            if (TempData.ContainsKey(AlreadyEnabledFeatures)) {
+
+                var alreadyEnabledFeatures = TempData[AlreadyEnabledFeatures] as IEnumerable<string>;
+                if (alreadyEnabledFeatures != null) {
+                    var afterEnabledFeatures = GetEnabledFeatures();
+                    if (afterEnabledFeatures.Count() > alreadyEnabledFeatures.Count()) {
+                        var disableFeatures = afterEnabledFeatures.Except(alreadyEnabledFeatures);
+                        _themeService.DisablePreviewFeatures(disableFeatures);
+                    }
+                }
+            }
+
             _previewTheme.SetPreviewTheme(null);
 
             return RedirectToAction("Index");
@@ -256,5 +273,9 @@ namespace Orchard.Themes.Controllers {
                 return string.IsNullOrEmpty(value);
             }
         }
+
+        public IEnumerable<string> GetEnabledFeatures() {
+            return _featureManager.GetEnabledFeatures().Select(f => f.Id);
+        }
     }
 }

src/Orchard.Web/Modules/Orchard.Themes/Events/ThemeDisableEventHandler.cs

@@ -0,0 +1,61 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Orchard.Environment;
+using Orchard.Environment.Extensions.Models;
+using Orchard.Environment.Features;
+using Orchard.Localization;
+using Orchard.Themes.Services;
+using Orchard.UI.Notify;
+
+namespace Orchard.Themes.Events {
+    public class ThemeDisableEventHandler : IFeatureEventHandler {
+        private readonly IFeatureManager _featureManager;
+        private readonly ISiteThemeService _siteThemeService;
+        private readonly INotifier _notifier;
+
+        public ThemeDisableEventHandler(
+            IFeatureManager featureManager,
+            ISiteThemeService siteThemeService,
+            INotifier notifier) {
+            _featureManager = featureManager;
+            _siteThemeService = siteThemeService;
+            _notifier = notifier;
+
+            T = NullLocalizer.Instance;
+        }
+
+        public Localizer T { get; set; }
+
+        public void Installing(Feature feature) {
+        }
+
+        public void Installed(Feature feature) {
+        }
+
+        public void Enabling(Feature feature) {
+        }
+
+        public void Enabled(Feature feature) {
+        }
+
+        public void Disabling(Feature feature) {
+        }
+
+        public void Disabled(Feature feature) {
+            var currentTheme = _siteThemeService.GetCurrentThemeName();
+            if (feature.Descriptor.Name == currentTheme) {
+                _siteThemeService.SetSiteTheme(null);
+
+                // Notifications don't work in feature events. See: https://github.com/OrchardCMS/Orchard/issues/6106
+                _notifier.Warning(T("The current theme was disabled, because one of its dependencies was disabled."));
+            }
+        }
+
+        public void Uninstalling(Feature feature) {
+        }
+
+        public void Uninstalled(Feature feature) {
+        }
+    }
+}

src/Orchard.Web/Modules/Orchard.Themes/Orchard.Themes.csproj

@@ -66,6 +66,7 @@
     <Compile Include="AdminMenu.cs" />
     <Compile Include="Commands\ThemeCommands.cs" />
     <Compile Include="Drivers\DisableThemePartDriver.cs" />
+    <Compile Include="Events\ThemeDisableEventHandler.cs" />
     <Compile Include="Events\IExtensionDisplayEventHandler.cs" />
     <Compile Include="Migrations.cs" />
     <Compile Include="Models\ThemeEntry.cs" />

src/Orchard.Web/Modules/Orchard.Themes/Services/IThemeService.cs

@@ -1,9 +1,11 @@
-using Orchard.Environment.Extensions.Models;
+using System.Collections.Generic;
+using Orchard.Environment.Extensions.Models;
 
 namespace Orchard.Themes.Services {
     public interface IThemeService : IDependency {
         void DisableThemeFeatures(string themeName);
         void EnableThemeFeatures(string themeName);
         bool IsRecentlyInstalled(ExtensionDescriptor module);
+        void DisablePreviewFeatures(IEnumerable<string> features);
     }
 }

src/Orchard.Web/Modules/Orchard.Themes/Services/ThemeService.cs

@@ -20,6 +20,7 @@ namespace Orchard.Themes.Services {
         private readonly IEnumerable<IThemeSelector> _themeSelectors;
         private readonly IVirtualPathProvider _virtualPathProvider;
         private readonly ICacheManager _cacheManager;
+        private readonly ISiteThemeService _siteThemeService;
 
         public ThemeService(
             IOrchardServices orchardServices,
@@ -27,7 +28,8 @@ namespace Orchard.Themes.Services {
             IFeatureManager featureManager,
             IEnumerable<IThemeSelector> themeSelectors,
             IVirtualPathProvider virtualPathProvider,
-            ICacheManager cacheManager) {
+            ICacheManager cacheManager,
+            ISiteThemeService siteThemeService) {
 
             Services = orchardServices;
 
@@ -36,6 +38,7 @@ namespace Orchard.Themes.Services {
             _themeSelectors = themeSelectors;
             _virtualPathProvider = virtualPathProvider;
             _cacheManager = cacheManager;
+            _siteThemeService = siteThemeService;
 
             if (_featureManager.FeatureDependencyNotification == null) {
                 _featureManager.FeatureDependencyNotification = GenerateWarning;
@@ -64,8 +67,16 @@ namespace Orchard.Themes.Services {
                     : null;
             }
 
-            while (themes.Count > 0)
-                _featureManager.DisableFeatures(new[] { themes.Dequeue() });
+            var currentTheme = _siteThemeService.GetCurrentThemeName();
+
+            while (themes.Count > 0) {
+                var themeId = themes.Dequeue();
+
+                // Not disabling base theme if it's the current theme.
+                if (themeId != currentTheme) {
+                    _featureManager.DisableFeatures(new[] { themeId });
+                }
+            }
         }
 
         public void EnableThemeFeatures(string themeName) {
@@ -81,8 +92,15 @@ namespace Orchard.Themes.Services {
                     : null;
             }
 
-            while (themes.Count > 0)
-                _featureManager.EnableFeatures(new[] {themes.Pop()});
+            while (themes.Count > 0) {
+                var themeId = themes.Pop();
+                foreach (var featureId in _featureManager.EnableFeatures(new[] { themeId }, true)) {
+                    if (themeId != featureId) {
+                        var featureName = _featureManager.GetAvailableFeatures().First(f => f.Id.Equals(featureId, StringComparison.OrdinalIgnoreCase)).Name;
+                        Services.Notifier.Information(T("{0} was enabled", featureName));
+                    }
+                }
+            }
         }
 
         public ExtensionDescriptor GetRequestTheme(RequestContext requestContext) {
@@ -174,5 +192,12 @@ namespace Orchard.Themes.Services {
                                                    : "{0}, "), fn).ToString()).ToArray())
                     : featuresInQuestion.First()));
         }
+
+        public void DisablePreviewFeatures(IEnumerable<string> features) {
+             foreach (var featureId in _featureManager.DisableFeatures(features,true)) {
+                 var featureName = _featureManager.GetAvailableFeatures().First(f => f.Id.Equals(featureId, StringComparison.OrdinalIgnoreCase)).Name;
+                        Services.Notifier.Information(T("{0} was disabled", featureName));
+             }
+        }
     }
 }