#8862: Preventing the SQL Server Service Broker feature from being enabled when not using SQL Server (Lombiq Technologies: ORCH-309) (#8875)

Author: I3undy

src/Orchard.Web/Modules/Orchard.MessageBus/Orchard.MessageBus.csproj

@@ -130,6 +130,7 @@
     <Compile Include="Services\IHostNameProvider.cs" />
     <Compile Include="Services\MessageBusNotificationProvider.cs" />
     <Compile Include="Handler\MessageBusHandler.cs" />
+    <Compile Include="Services\SqlServerServiceBrokerFeatureGuard.cs" />
     <Compile Include="SqlServerBrokerMigrations.cs" />
     <Compile Include="Models\MessageRecord.cs" />
     <Compile Include="Services\DefaultMessageBus.cs" />

src/Orchard.Web/Modules/Orchard.MessageBus/Services/SqlServerServiceBrokerFeatureGuard.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Web.Mvc;
+using Orchard.Environment;
+using Orchard.Environment.Configuration;
+using Orchard.Environment.Extensions.Models;
+using Orchard.Environment.Features;
+using Orchard.Localization;
+using Orchard.Mvc;
+using Orchard.Mvc.Filters;
+using Orchard.UI.Notify;
+
+namespace Orchard.MessageBus.Services
+{
+    /// <summary>
+    /// Prevents the SQL Server Service Broker feature from being enabled for tenants that are not using Microsoft SQL
+    /// Server as their database provider.
+    /// </summary>
+    /// <remarks>
+    /// The implementation is hackish but there seems to be no other way: if it would use <see cref="INotifier"/> it
+    /// wouldn't work since <see cref="NotifyFilter"/> that writes out notifications to TempData runs before feature
+    /// events are raised. Thus we have to manually add the messages to TempData, just as the filter would do.
+    /// </remarks>
+    public class SqlServerServiceBrokerFeatureGuard : FilterProvider, IFeatureEventHandler, IActionFilter
+    {
+        private const string FeatureId = "Orchard.MessageBus.SqlServerServiceBroker";
+        private const string TempDataKey = FeatureId + ".TempData";
+
+        private readonly ShellSettings _shellSettings;
+        private readonly IFeatureManager _featureManager;
+        private readonly IHttpContextAccessor _hca;
+
+        public Localizer T { get; set; }
+
+        public SqlServerServiceBrokerFeatureGuard(
+            ShellSettings shellSettings,
+            IFeatureManager featureManager,
+            IHttpContextAccessor hca)
+        {
+            _shellSettings = shellSettings;
+            _featureManager = featureManager;
+            _hca = hca;
+
+            T = NullLocalizer.Instance;
+        }
+
+        void IActionFilter.OnActionExecuting(ActionExecutingContext filterContext) { }
+
+        void IActionFilter.OnActionExecuted(ActionExecutedContext filterContext)
+        {
+            var httpContext = _hca.Current();
+
+            if (httpContext == null) return;
+
+            httpContext.Items[TempDataKey] = filterContext.Controller.TempData;
+        }
+
+        public void Installing(Feature feature) { }
+
+        public void Installed(Feature feature) { }
+
+        public void Enabling(Feature feature) { }
+
+        public void Enabled(Feature feature)
+        {
+            if (feature.Descriptor.Id != FeatureId)
+                return;
+
+            if (!_shellSettings.DataProvider.Equals("SqlServer", StringComparison.OrdinalIgnoreCase))
+            {
+                _featureManager.DisableFeatures(new[] { FeatureId }, force: true);
+
+                AddNotification(
+                    T("The SQL Server Service Broker cannot be enabled because it requires Microsoft SQL Server."),
+                    NotifyType.Error);
+            }
+        }
+
+        public void Disabling(Feature feature) { }
+
+        public void Disabled(Feature feature) { }
+
+        public void Uninstalling(Feature feature) { }
+
+        public void Uninstalled(Feature feature) { }
+
+        private void AddNotification(LocalizedString message, NotifyType notifyType = NotifyType.Warning)
+        {
+            var tempDataDictionary = _hca.Current()?.Items[TempDataKey];
+
+            if (tempDataDictionary == null) return;
+
+            ((TempDataDictionary)tempDataDictionary)["messages"] +=
+                $"{notifyType}:{message.Text}{System.Environment.NewLine}-{System.Environment.NewLine}";
+        }
+    }
+}