Updated FeatureGateAttribute to be able to be used on Razor Pages. (#166

)

* Add PageFeatureGate

* Fix tests.

* Remove test page.

* Added missing license headers.

* Bundle PageFeatureGateAttribute functionality into FeatureGate. Page filters and action filter execution is isolated.

* Use OkResult instead of StatusCode. Updated indenting.

* Remove unnecessary virtual for interface implementation.

* Add back netcoreapp2.1 in tests.

* Remove tabs from csproj

Microsoft.FeatureManagement.sln

@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 16
-VisualStudioVersion = 16.0.29011.400
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31825.309
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "FeatureFlagDemo", "examples\FeatureFlagDemo\FeatureFlagDemo.csproj", "{E58A64A6-BE10-4D7A-AAB8-C3E2925CB32F}"
 EndProject
@@ -19,6 +19,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ConsoleApp", "examples\Cons
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "TargetingConsoleApp", "examples\TargetingConsoleApp\TargetingConsoleApp.csproj", "{6558C21E-CF20-4278-AA08-EB9D1DF29D66}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "RazorPages", "examples\RazorPages\RazorPages.csproj", "{BA29A1BB-81D5-4EB1-AF37-6ECF64AF27E2}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -49,6 +51,10 @@ Global
 		{6558C21E-CF20-4278-AA08-EB9D1DF29D66}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{6558C21E-CF20-4278-AA08-EB9D1DF29D66}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{6558C21E-CF20-4278-AA08-EB9D1DF29D66}.Release|Any CPU.Build.0 = Release|Any CPU
+		{BA29A1BB-81D5-4EB1-AF37-6ECF64AF27E2}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{BA29A1BB-81D5-4EB1-AF37-6ECF64AF27E2}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{BA29A1BB-81D5-4EB1-AF37-6ECF64AF27E2}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{BA29A1BB-81D5-4EB1-AF37-6ECF64AF27E2}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -58,6 +64,7 @@ Global
 		{FDBB27BA-C5BA-48A7-BA9B-63159943EA9F} = {8ED6FFEE-4037-49A2-9709-BC519C104A90}
 		{E50FB931-7A42-440E-AC47-B8DFE5E15394} = {FB5C34DF-695C-4DF9-8AED-B3EA2516EA72}
 		{6558C21E-CF20-4278-AA08-EB9D1DF29D66} = {FB5C34DF-695C-4DF9-8AED-B3EA2516EA72}
+		{BA29A1BB-81D5-4EB1-AF37-6ECF64AF27E2} = {FB5C34DF-695C-4DF9-8AED-B3EA2516EA72}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {84DA6C54-F140-4518-A1B4-E4CF42117FBD}

examples/RazorPages/Pages/Error.cshtml

@@ -0,0 +1,26 @@
+@page
+@model ErrorModel
+@{
+    ViewData["Title"] = "Error";
+}
+
+<h1 class="text-danger">Error.</h1>
+<h2 class="text-danger">An error occurred while processing your request.</h2>
+
+@if (Model.ShowRequestId)
+{
+    <p>
+        <strong>Request ID:</strong> <code>@Model.RequestId</code>
+    </p>
+}
+
+<h3>Development Mode</h3>
+<p>
+    Swapping to the <strong>Development</strong> environment displays detailed information about the error that occurred.
+</p>
+<p>
+    <strong>The Development environment shouldn't be enabled for deployed applications.</strong>
+    It can result in displaying sensitive information from exceptions to end users.
+    For local debugging, enable the <strong>Development</strong> environment by setting the <strong>ASPNETCORE_ENVIRONMENT</strong> environment variable to <strong>Development</strong>
+    and restarting the app.
+</p>

examples/RazorPages/Pages/Error.cshtml.cs

@@ -0,0 +1,30 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using System.Diagnostics;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using Microsoft.Extensions.Logging;
+
+namespace RazorPages.Pages
+{
+    [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
+    public class ErrorModel : PageModel
+    {
+        public string RequestId { get; set; }
+
+        public bool ShowRequestId => !string.IsNullOrEmpty(RequestId);
+
+        private readonly ILogger<ErrorModel> _logger;
+
+        public ErrorModel(ILogger<ErrorModel> logger)
+        {
+            _logger = logger;
+        }
+
+        public void OnGet()
+        {
+            RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier;
+        }
+    }
+}

examples/RazorPages/Pages/Index.cshtml

@@ -0,0 +1,22 @@
+@page
+@model IndexModel
+@{
+    ViewData["Title"] = "Home page";
+}
+
+<head>
+    <style>
+        .code {
+          font-family: Consolas, Menlo, Monaco, Lucida Console, Liberation Mono, DejaVu Sans Mono, Bitstream Vera Sans Mono, Courier New, monospace, serif;
+        }
+    </style>
+</head>
+
+<h1>
+    Razor Page Example
+</h1>
+<p>
+    This page uses the <span class="code">'PageGateAttribute'</span> to conditionally display this web page.
+    Since you are seeing this, that means the 'Home' feature is enabled.
+    If the 'Home' feature is disabled then the browser will display an HTTP 404 (Not Found) error page.
+</p>

examples/RazorPages/Pages/Index.cshtml.cs

@@ -0,0 +1,16 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using Microsoft.FeatureManagement.Mvc;
+
+namespace RazorPages.Pages
+{
+    [FeatureGate("Home")]
+    public class IndexModel : PageModel
+    {
+        public void OnGet()
+        {
+        }
+    }
+}

examples/RazorPages/Pages/_ViewImports.cshtml

@@ -0,0 +1,3 @@
+@using RazorPages
+@namespace RazorPages.Pages
+@addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

examples/RazorPages/Program.cs

@@ -0,0 +1,29 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace RazorPages
+{
+    public class Program
+    {
+        public static void Main(string[] args)
+        {
+            CreateHostBuilder(args).Build().Run();
+        }
+
+        public static IHostBuilder CreateHostBuilder(string[] args) =>
+            Host.CreateDefaultBuilder(args)
+                .ConfigureWebHostDefaults(webBuilder =>
+                {
+                    webBuilder.UseStartup<Startup>();
+                });
+    }
+}

examples/RazorPages/RazorPages.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Microsoft.FeatureManagement.AspNetCore\Microsoft.FeatureManagement.AspNetCore.csproj" />
+  </ItemGroup>
+
+</Project>

examples/RazorPages/Startup.cs

@@ -0,0 +1,58 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT license.
+//
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.FeatureManagement;
+
+namespace RazorPages
+{
+    public class Startup
+    {
+        public Startup(IConfiguration configuration)
+        {
+            Configuration = configuration;
+        }
+
+        public IConfiguration Configuration { get; }
+
+        // This method gets called by the runtime. Use this method to add services to the container.
+        public void ConfigureServices(IServiceCollection services)
+        {
+            services.AddFeatureManagement();
+
+            services.AddRazorPages();
+        }
+
+        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
+        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
+        {
+            if (env.IsDevelopment())
+            {
+                app.UseDeveloperExceptionPage();
+            }
+            else
+            {
+                app.UseExceptionHandler("/Error");
+                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
+                app.UseHsts();
+            }
+
+            app.UseHttpsRedirection();
+
+            app.UseRouting();
+
+            app.UseStaticFiles();
+
+            app.UseAuthorization();
+
+            app.UseEndpoints(o =>
+            {
+                o.MapRazorPages();
+            });
+        }
+    }
+}

examples/RazorPages/appsettings.Development.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft": "Warning",
+      "Microsoft.Hosting.Lifetime": "Information"
+    }
+  }
+}

examples/RazorPages/appsettings.json

@@ -0,0 +1,13 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft": "Warning",
+      "Microsoft.Hosting.Lifetime": "Information"
+    }
+  },
+    "AllowedHosts": "*",
+    "FeatureManagement": {
+        "Home": true
+    }
+}

src/Microsoft.FeatureManagement.AspNetCore/FeatureGateAttribute.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation.
 // Licensed under the MIT license.
 //
+using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.Mvc.Filters;
 using Microsoft.Extensions.DependencyInjection;
 using System;
@@ -14,7 +15,7 @@ namespace Microsoft.FeatureManagement.Mvc
     /// An attribute that can be placed on MVC actions to require all or any of a set of features to be enabled. If none of the feature are enabled the registered <see cref="IDisabledFeaturesHandler"/> will be invoked.
     /// </summary>
     [AttributeUsage(AttributeTargets.Method | AttributeTargets.Class, AllowMultiple = true)]
-    public class FeatureGateAttribute : ActionFilterAttribute
+    public class FeatureGateAttribute : ActionFilterAttribute, IAsyncPageFilter
     {
         /// <summary>
         /// Creates an attribute that will gate actions unless all the provided feature(s) are enabled.
@@ -120,5 +121,38 @@ await Features.All(async feature => await fm.IsEnabledAsync(feature).ConfigureAw
                 await disabledFeaturesHandler.HandleDisabledFeatures(Features, context).ConfigureAwait(false);
             }
         }
+
+        /// <summary>
+        /// Called asynchronously before the handler method is invoked, after model binding is complete.
+        /// </summary>
+        /// <param name="context">The <see cref="PageHandlerExecutingContext"/>.</param>
+        /// <param name="next">The <see cref="PageHandlerExecutionDelegate"/>. Invoked to execute the next page filter or the handler method itself.</param>
+        /// <returns>A <see cref="Task"/> that on completion indicates the filter has executed.</returns>
+        public async Task OnPageHandlerExecutionAsync(PageHandlerExecutingContext context, PageHandlerExecutionDelegate next)
+        {
+            IFeatureManagerSnapshot fm = context.HttpContext.RequestServices.GetRequiredService<IFeatureManagerSnapshot>();
+
+            //
+            // Enabled state is determined by either 'any' or 'all' features being enabled.
+            bool enabled = RequirementType == RequirementType.All ?
+                             await Features.All(async feature => await fm.IsEnabledAsync(feature).ConfigureAwait(false)) :
+                             await Features.Any(async feature => await fm.IsEnabledAsync(feature).ConfigureAwait(false));
+
+            if (enabled)
+            {
+                await next.Invoke().ConfigureAwait(false);
+            }
+            else
+            {
+                context.Result = new NotFoundResult();
+            }
+        }
+
+        /// <summary>
+        /// Called asynchronously after the handler method has been selected, but before model binding occurs.
+        /// </summary>
+        /// <param name="context">The <see cref="PageHandlerSelectedContext"/>.</param>
+        /// <returns>A <see cref="Task"/> that on completion indicates the filter has executed.</returns>
+        public Task OnPageHandlerSelectionAsync(PageHandlerSelectedContext context) => Task.CompletedTask;
     }
 }

src/Microsoft.FeatureManagement.AspNetCore/Microsoft.FeatureManagement.AspNetCore.csproj

@@ -33,11 +33,12 @@
     <ProjectReference Include="..\Microsoft.FeatureManagement\Microsoft.FeatureManagement.csproj" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'" >
+  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
+    <PackageReference Include="Microsoft.AspNetCore.Mvc.RazorPages" Version="2.1.11" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.TagHelpers" Version="2.1.3" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0'" >
+  <ItemGroup Condition="'$(TargetFramework)' != 'netstandard2.0'">
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
   </ItemGroup>
 

tests/Tests.FeatureManagement/FeatureManagement.cs

@@ -171,6 +171,60 @@ public async Task GatesFeatures()
             Assert.Equal(HttpStatusCode.NotFound, gateAllResponse.StatusCode);
             Assert.Equal(HttpStatusCode.NotFound, gateAnyResponse.StatusCode);
         }
+
+        [Fact]
+        public async Task GatesRazorPageFeatures()
+        {
+            IConfiguration config = new ConfigurationBuilder().AddJsonFile("appsettings.json").Build();
+
+            TestServer testServer = new TestServer(WebHost.CreateDefaultBuilder().ConfigureServices(services =>
+            {
+                services
+                    .AddSingleton(config)
+                    .AddFeatureManagement()
+                    .AddFeatureFilter<TestFilter>();
+
+                services.AddMvc(o => DisableEndpointRouting(o));
+            })
+            .Configure(app => 
+            {
+                app.UseMvc();
+            }));
+
+            IEnumerable<IFeatureFilterMetadata> featureFilters = testServer.Host.Services.GetRequiredService<IEnumerable<IFeatureFilterMetadata>>();
+
+            TestFilter testFeatureFilter = (TestFilter)featureFilters.First(f => f is TestFilter);
+
+            //
+            // Enable all features
+            testFeatureFilter.Callback = ctx => Task.FromResult(true);
+
+            HttpResponseMessage gateAllResponse = await testServer.CreateClient().GetAsync("RazorTestAll");
+            HttpResponseMessage gateAnyResponse = await testServer.CreateClient().GetAsync("RazorTestAny");
+
+            Assert.Equal(HttpStatusCode.OK, gateAllResponse.StatusCode);
+            Assert.Equal(HttpStatusCode.OK, gateAnyResponse.StatusCode);
+
+            //
+            // Enable 1/2 features
+            testFeatureFilter.Callback = ctx => Task.FromResult(ctx.FeatureName == Enum.GetName(typeof(Features), Features.ConditionalFeature));
+
+            gateAllResponse = await testServer.CreateClient().GetAsync("RazorTestAll");
+            gateAnyResponse = await testServer.CreateClient().GetAsync("RazorTestAny");
+
+            Assert.Equal(HttpStatusCode.NotFound, gateAllResponse.StatusCode);
+            Assert.Equal(HttpStatusCode.OK, gateAnyResponse.StatusCode);
+
+            //
+            // Enable no
+            testFeatureFilter.Callback = ctx => Task.FromResult(false);
+
+            gateAllResponse = await testServer.CreateClient().GetAsync("RazorTestAll");
+            gateAnyResponse = await testServer.CreateClient().GetAsync("RazorTestAny");
+
+            Assert.Equal(HttpStatusCode.NotFound, gateAllResponse.StatusCode);
+            Assert.Equal(HttpStatusCode.NotFound, gateAnyResponse.StatusCode);
+        }
 
         [Fact]
         public async Task TimeWindow()