Update to newer API designs

Author: SteveSandersonMS

src/Microsoft.AspNetCore.SpaServices/AngularCli/AngularCliBuilder.cs

@@ -1,9 +1,9 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.SpaServices.Prerendering;
 using System;
-using System.Linq;
 using System.Threading.Tasks;
 
 namespace Microsoft.AspNetCore.SpaServices.AngularCli
@@ -26,18 +26,22 @@ public AngularCliBuilder(string cliAppName)
         }
 
         /// <inheritdoc />
-        public Task Build(ISpaBuilder spaBuilder)
+        public Task Build(IApplicationBuilder app)
         {
-            // Locate the AngularCliMiddleware within the provided ISpaBuilder
-            var angularCliMiddleware = spaBuilder
-                .Properties.Keys.OfType<AngularCliMiddleware>().FirstOrDefault();
-            if (angularCliMiddleware == null)
+            // Locate the AngularCliMiddleware within the provided IApplicationBuilder
+            if (app.Properties.TryGetValue(
+                AngularCliMiddleware.AngularCliMiddlewareKey,
+                out var angularCliMiddleware))
+            {
+                return ((AngularCliMiddleware)angularCliMiddleware)
+                    .StartAngularCliBuilderAsync(_cliAppName);
+            }
+            else
             {
                 throw new Exception(
-                    $"Cannot use {nameof (AngularCliBuilder)} unless you are also using {nameof(AngularCliMiddleware)}.");
+                    $"Cannot use {nameof(AngularCliBuilder)} unless you are also using" +
+                    $" {nameof(AngularCliMiddlewareExtensions.UseAngularCliServer)}.");
             }
-
-            return angularCliMiddleware.StartAngularCliBuilderAsync(_cliAppName);
         }
     }
 }

src/Microsoft.AspNetCore.SpaServices/AngularCli/AngularCliMiddleware.cs

@@ -9,40 +9,41 @@
 using Microsoft.AspNetCore.Hosting;
 using System.Threading;
 using Microsoft.AspNetCore.SpaServices.Proxy;
+using Microsoft.AspNetCore.Http;
 
 namespace Microsoft.AspNetCore.SpaServices.AngularCli
 {
     internal class AngularCliMiddleware
     {
         private const string _middlewareResourceName = "/Content/Node/angular-cli-middleware.js";
 
+        internal readonly static string AngularCliMiddlewareKey = Guid.NewGuid().ToString();
+
         private readonly INodeServices _nodeServices;
         private readonly string _middlewareScriptPath;
 
-        public AngularCliMiddleware(ISpaBuilder spaBuilder, string sourcePath)
+        public AngularCliMiddleware(IApplicationBuilder appBuilder, string sourcePath, string urlPrefix, string defaultPage)
         {
             if (string.IsNullOrEmpty(sourcePath))
             {
                 throw new ArgumentException("Cannot be null or empty", nameof(sourcePath));
             }
 
             // Prepare to make calls into Node
-            var appBuilder = spaBuilder.AppBuilder;
             _nodeServices = CreateNodeServicesInstance(appBuilder, sourcePath);
             _middlewareScriptPath = GetAngularCliMiddlewareScriptPath(appBuilder);
 
             // Start Angular CLI and attach to middleware pipeline
             var angularCliServerInfoTask = StartAngularCliServerAsync();
-            spaBuilder.AddStartupTask(angularCliServerInfoTask);
 
             // Proxy the corresponding requests through ASP.NET and into the Node listener
             // Anything under /<publicpath> (e.g., /dist) is proxied as a normal HTTP request
             // with a typical timeout (100s is the default from HttpClient).
-            UseProxyToLocalAngularCliMiddleware(appBuilder, spaBuilder.PublicPath,
+            UseProxyToLocalAngularCliMiddleware(appBuilder, urlPrefix, defaultPage,
                 angularCliServerInfoTask, TimeSpan.FromSeconds(100));
 
             // Advertise the availability of this feature to other SPA middleware
-            spaBuilder.Properties.Add(this, null);
+            appBuilder.Properties.Add(AngularCliMiddlewareKey, this);
         }
 
         public Task StartAngularCliBuilderAsync(string cliAppName)
@@ -65,6 +66,11 @@ private static INodeServices CreateNodeServicesInstance(
                 ProjectPath = Path.Combine(Directory.GetCurrentDirectory(), sourcePath),
             };
 
+            if (!Directory.Exists(nodeServicesOptions.ProjectPath))
+            {
+                throw new DirectoryNotFoundException($"Directory not found: {nodeServicesOptions.ProjectPath}");
+            }
+
             return NodeServicesFactory.CreateNodeServices(nodeServicesOptions);
         }
 
@@ -99,7 +105,7 @@ private async Task<AngularCliServerInfo> StartAngularCliServerAsync()
         }
 
         private static void UseProxyToLocalAngularCliMiddleware(
-            IApplicationBuilder appBuilder, string publicPath,
+            IApplicationBuilder appBuilder, string urlPrefix, string defaultPage,
             Task<AngularCliServerInfo> serverInfoTask, TimeSpan requestTimeout)
         {
             // This is hardcoded to use http://localhost because:
@@ -110,7 +116,37 @@ private static void UseProxyToLocalAngularCliMiddleware(
             var proxyOptionsTask = serverInfoTask.ContinueWith(
                 task => new ConditionalProxyMiddlewareTarget(
                     "http", "localhost", task.Result.Port.ToString()));
-            appBuilder.UseMiddleware<ConditionalProxyMiddleware>(publicPath, requestTimeout, proxyOptionsTask);
+
+            // Requests outside /<urlPrefix> are proxied to the default page
+            var hasRewrittenUrlMarker = new object();
+            var defaultPageUrl = SpaDefaultPageExtensions.GetDefaultPageUrl(
+                urlPrefix, defaultPage);
+            var urlPrefixIsRoot = string.IsNullOrEmpty(urlPrefix) || urlPrefix == "/";
+            appBuilder.Use((context, next) =>
+            {
+                if (!urlPrefixIsRoot && !context.Request.Path.StartsWithSegments(urlPrefix))
+                {
+                    context.Items[hasRewrittenUrlMarker] = context.Request.Path;
+                    context.Request.Path = defaultPageUrl;
+                }
+
+                return next();
+            });
+
+            appBuilder.UseMiddleware<ConditionalProxyMiddleware>(urlPrefix, requestTimeout, proxyOptionsTask);
+
+            // If we rewrote the path, rewrite it back. Don't want to interfere with
+            // any other middleware.
+            appBuilder.Use((context, next) =>
+            {
+                if (context.Items.ContainsKey(hasRewrittenUrlMarker))
+                {
+                    context.Request.Path = (PathString)context.Items[hasRewrittenUrlMarker];
+                    context.Items.Remove(hasRewrittenUrlMarker);
+                }
+
+                return next();
+            });
         }
 
 #pragma warning disable CS0649

src/Microsoft.AspNetCore.SpaServices/AngularCli/AngularCliMiddlewareExtensions.cs

@@ -1,6 +1,8 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using Microsoft.AspNetCore.Builder;
+
 namespace Microsoft.AspNetCore.SpaServices.AngularCli
 {
     /// <summary>
@@ -9,23 +11,24 @@ namespace Microsoft.AspNetCore.SpaServices.AngularCli
     public static class AngularCliMiddlewareExtensions
     {
         /// <summary>
-        /// Enables Angular CLI middleware support. This hosts an instance of the Angular CLI in memory in
-        /// your application so that you can always serve up-to-date CLI-built resources without having
-        /// to run CLI server manually.
-        ///
-        /// Incoming requests that match Angular CLI-built files will be handled by returning the CLI server
-        /// output directly.
+        /// Handles requests by passing them through to an instance of the Angular CLI server.
+        /// This means you can always serve up-to-date CLI-built resources without having
+        /// to run the Angular CLI server manually.
         ///
-        /// This feature should only be used in development. For production deployments, be sure not to
-        /// enable Angular CLI middleware.
+        /// This feature should only be used in development. For production deployments, be
+        /// sure not to enable the Angular CLI server.
         /// </summary>
-        /// <param name="spaBuilder">The <see cref="ISpaBuilder"/>.</param>
-        /// <param name="sourcePath">The path, relative to the application root, of the directory containing the SPA source files.</param>
-        public static void UseAngularCliMiddleware(
-            this ISpaBuilder spaBuilder,
-            string sourcePath)
+        /// <param name="app">The <see cref="IApplicationBuilder"/>.</param>
+        /// <param name="sourcePath">The disk path, relative to the current directory, of the directory containing the SPA source files. When Angular CLI executes, this will be its working directory.</param>
+        /// <param name="urlPrefix">The URL prefix from which your SPA's files are served. This needs to match the <c>--deploy-url</c> option passed to Angular CLI.</param>
+        /// <param name="defaultPage">Optional. Specifies the URL, relative to <paramref name="urlPrefix"/>, of the default HTML page that starts up your SPA. Defaults to <c>index.html</c>.</param>
+        public static void UseAngularCliServer(
+            this IApplicationBuilder app,
+            string sourcePath,
+            string urlPrefix,
+            string defaultPage = null)
         {
-            new AngularCliMiddleware(spaBuilder, sourcePath);
+            new AngularCliMiddleware(app, sourcePath, urlPrefix, defaultPage);
         }
     }
 }

src/Microsoft.AspNetCore.SpaServices/DefaultSpaBuilder.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using Microsoft.AspNetCore.Builder;
 using System.Threading.Tasks;
 
 namespace Microsoft.AspNetCore.SpaServices.Prerendering
@@ -17,8 +18,8 @@ public interface ISpaPrerendererBuilder
         /// exists on disk. Prerendering middleware can then execute that file in
         /// a Node environment.
         /// </summary>
-        /// <param name="spaBuilder">The <see cref="ISpaBuilder"/>.</param>
+        /// <param name="appBuilder">The <see cref="IApplicationBuilder"/>.</param>
         /// <returns>A <see cref="Task"/> representing completion of the build process.</returns>
-        Task Build(ISpaBuilder spaBuilder);
+        Task Build(IApplicationBuilder appBuilder);
     }
 }