Add IDocumentProvider service and its implementation (2)

.gitignore

@@ -65,3 +65,5 @@ NSwagStudio*.nupkg
 /samples/WithoutMiddleware/Sample.AspNetCore20/.vs/Sample.AspNetCore20/v15/Server/sqlite3
 /samples/WithoutMiddleware/Sample.AspNetCore20/.vs/Sample.AspNetCore20/DesignTimeBuild
 /samples/.vs/*
+.vscode/
+/src/.cr/*

src/NSwag.AspNetCore/IDocumentProvider.cs

@@ -0,0 +1,20 @@
+//-----------------------------------------------------------------------
+// <copyright file="IDocumentProvider.cs" company="NSwag">
+//     Copyright (c) Rico Suter. All rights reserved.
+// </copyright>
+// <license>https://github.com/NSwag/NSwag/blob/master/LICENSE.md</license>
+// <author>Rico Suter, mail@rsuter.com</author>
+//-----------------------------------------------------------------------
+
+using System.IO;
+using System.Threading.Tasks;
+
+namespace Microsoft.Extensions.ApiDescription
+{
+    // This service will be looked up by name from the service collection when using
+    // the Microsoft.Extensions.ApiDescription tool
+    internal interface IDocumentProvider
+    {
+        Task GenerateAsync(string documentName, TextWriter writer);
+    }
+}

src/NSwag.AspNetCore/Middlewares/AspNetCoreToSwaggerMiddleware.cs → src/NSwag.AspNetCore/Middlewares/SwaggerMiddleware.cs

@@ -6,106 +6,108 @@
 // <author>Rico Suter, mail@rsuter.com</author>
 //-----------------------------------------------------------------------
 
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc.ApiExplorer;
+using Microsoft.Extensions.DependencyInjection;
 using System;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
-using Microsoft.AspNetCore.Mvc;
-using Microsoft.AspNetCore.Mvc.ApiExplorer;
-using Microsoft.Extensions.Options;
-using NSwag.SwaggerGeneration;
-using NSwag.SwaggerGeneration.AspNetCore;
 
 namespace NSwag.AspNetCore.Middlewares
 {
     /// <summary>Generates a Swagger specification on a given path.</summary>
-    public class AspNetCoreToSwaggerMiddleware
+    public class SwaggerMiddleware
     {
         private readonly RequestDelegate _nextDelegate;
-        private readonly string _path;
-        private readonly SwaggerSettings<AspNetCoreToSwaggerGeneratorSettings> _settings;
-        private readonly SwaggerJsonSchemaGenerator _schemaGenerator;
+        private readonly string _documentName;
         private readonly IApiDescriptionGroupCollectionProvider _apiDescriptionGroupCollectionProvider;
-        private readonly IOptions<MvcOptions> _mvcOptions;
-        private readonly IOptions<MvcJsonOptions> _mvcJsonOptions;
+        private readonly SwaggerDocumentProvider _documentProvider;
+        private readonly SwaggerMiddlewareSettings _settings;
 
         private int _version;
-        private string _schemaJson;
-        private Exception _schemaException;
+        private string _swaggerJson;
+        private Exception _swaggerException;
         private DateTimeOffset _schemaTimestamp;
 
         /// <summary>Initializes a new instance of the <see cref="WebApiToSwaggerMiddleware"/> class.</summary>
         /// <param name="nextDelegate">The next delegate.</param>
-        /// <param name="apiDescriptionGroupCollectionProvider">The <see cref="IApiDescriptionGroupCollectionProvider"/>.</param>
-        /// <param name="mvcOptions">The options.</param>
-        /// <param name="mvcJsonOptions">The json options.</param>
-        /// <param name="settings">The settings.</param>
-        /// <param name="schemaGenerator">The schema generator.</param>
-        public AspNetCoreToSwaggerMiddleware(RequestDelegate nextDelegate, IApiDescriptionGroupCollectionProvider apiDescriptionGroupCollectionProvider, IOptions<MvcOptions> mvcOptions, IOptions<MvcJsonOptions> mvcJsonOptions, SwaggerSettings<AspNetCoreToSwaggerGeneratorSettings> settings, SwaggerJsonSchemaGenerator schemaGenerator)
+        public SwaggerMiddleware(
+            RequestDelegate nextDelegate,
+            IServiceProvider serviceProvider,
+            string documentName,
+            Action<SwaggerMiddlewareSettings> configure)
         {
             _nextDelegate = nextDelegate;
+            _documentName = documentName;
+
+            _apiDescriptionGroupCollectionProvider = serviceProvider.GetService<IApiDescriptionGroupCollectionProvider>() ??
+                throw new InvalidOperationException("API Explorer not registered in DI.");
+            _documentProvider = serviceProvider.GetService<SwaggerDocumentProvider>() ??
+                throw new InvalidOperationException("The NSwag DI services are not registered: Call " + nameof(SwaggerExtensions.AddSwagger) + " in ConfigureServices().");
+
+            var settings = new SwaggerMiddlewareSettings();
+            configure?.Invoke(settings);
             _settings = settings;
-            _path = settings.ActualSwaggerRoute;
-            _schemaGenerator = schemaGenerator;
-            _apiDescriptionGroupCollectionProvider = apiDescriptionGroupCollectionProvider;
-            _mvcOptions = mvcOptions;
-            _mvcJsonOptions = mvcJsonOptions;
         }
 
         /// <summary>Invokes the specified context.</summary>
         /// <param name="context">The context.</param>
         /// <returns>The task.</returns>
         public async Task Invoke(HttpContext context)
         {
-            if (context.Request.Path.HasValue && string.Equals(context.Request.Path.Value.Trim('/'), _path.Trim('/'), StringComparison.OrdinalIgnoreCase))
+            if (context.Request.Path.HasValue && string.Equals(context.Request.Path.Value.Trim('/'), _settings.Path.Trim('/'), StringComparison.OrdinalIgnoreCase))
             {
                 var schemaJson = await GenerateSwaggerAsync(context);
                 context.Response.StatusCode = 200;
                 context.Response.Headers["Content-Type"] = "application/json; charset=utf-8";
                 await context.Response.WriteAsync(schemaJson);
             }
             else
+            {
                 await _nextDelegate(context);
+            }
         }
 
         /// <summary>Generates the Swagger specification.</summary>
         /// <param name="context">The context.</param>
         /// <returns>The Swagger specification.</returns>
         protected virtual async Task<string> GenerateSwaggerAsync(HttpContext context)
         {
-            if (_schemaException != null && _schemaTimestamp + _settings.ExceptionCacheTime > DateTimeOffset.UtcNow)
-                throw _schemaException;
+            if (_swaggerException != null && _schemaTimestamp + _settings.ExceptionCacheTime > DateTimeOffset.UtcNow)
+            {
+                throw _swaggerException;
+            }
 
             var apiDescriptionGroups = _apiDescriptionGroupCollectionProvider.ApiDescriptionGroups;
-            if (apiDescriptionGroups.Version == Volatile.Read(ref _version) && _schemaJson != null)
-                return _schemaJson;
+            if (apiDescriptionGroups.Version == Volatile.Read(ref _version) && _swaggerJson != null)
+            {
+                return _swaggerJson;
+            }
 
             try
             {
-                var serializerSettings = _mvcJsonOptions.Value.SerializerSettings;
-                var settings = _settings.CreateGeneratorSettings(serializerSettings, _mvcOptions.Value);
-                var generator = new AspNetCoreToSwaggerGenerator(settings, _schemaGenerator);
-                var document = await generator.GenerateAsync(apiDescriptionGroups);
+                var document = await _documentProvider.GenerateAsync(_documentName);
 
                 document.Host = context.Request.Host.Value ?? "";
                 document.Schemes.Add(context.Request.Scheme == "http" ? SwaggerSchema.Http : SwaggerSchema.Https);
                 document.BasePath = context.Request.PathBase.Value?.Substring(0, context.Request.PathBase.Value.Length - (_settings.MiddlewareBasePath?.Length ?? 0)) ?? "";
 
-                _settings.PostProcess?.Invoke(document);
-                _schemaJson = document.ToJson();
-                _schemaException = null;
+                _settings.PostProcess?.Invoke(context.Request, document);
+
+                _swaggerJson = document.ToJson();
+                _swaggerException = null;
                 _version = apiDescriptionGroups.Version;
                 _schemaTimestamp = DateTimeOffset.UtcNow;
             }
             catch (Exception exception)
             {
-                _schemaJson = null;
-                _schemaException = exception;
+                _swaggerJson = null;
+                _swaggerException = exception;
                 _schemaTimestamp = DateTimeOffset.UtcNow;
-                throw _schemaException;
+                throw _swaggerException;
             }
 
-            return _schemaJson;
+            return _swaggerJson;
         }
     }
 }

src/NSwag.AspNetCore/Middlewares/SwaggerMiddlewareSettings.cs

@@ -0,0 +1,29 @@
+//-----------------------------------------------------------------------
+// <copyright file="SwaggerMiddleware.cs" company="NSwag">
+//     Copyright (c) Rico Suter. All rights reserved.
+// </copyright>
+// <license>https://github.com/NSwag/NSwag/blob/master/LICENSE.md</license>
+// <author>Rico Suter, mail@rsuter.com</author>
+//-----------------------------------------------------------------------
+
+using Microsoft.AspNetCore.Http;
+using System;
+
+namespace NSwag.AspNetCore.Middlewares
+{
+    /// <summary>The Swagger middleware settings.</summary>
+    public class SwaggerMiddlewareSettings
+    {
+        /// <summary>Gets or sets the path to serve the OpenAPI/Swagger document.</summary>
+        public string Path { get; set; } = "swagger/v1/swagger.json";
+
+        /// <summary>Gets or sets for how long a <see cref="Exception"/> caught during schema generation is cached.</summary>
+        public TimeSpan ExceptionCacheTime { get; set; } = TimeSpan.FromSeconds(10);
+
+        /// <summary>Gets or sets the Swagger post process action.</summary>
+        public Action<HttpRequest, SwaggerDocument> PostProcess { get; set; }
+
+        /// <summary>Gets or sets the middleware base path (must start with '/').</summary>
+        public string MiddlewareBasePath { get; set; }
+    }
+}

src/NSwag.AspNetCore/SwaggerDocumentProvider.cs

@@ -0,0 +1,63 @@
+//-----------------------------------------------------------------------
+// <copyright file="NSwagDocumentProvider.cs" company="NSwag">
+//     Copyright (c) Rico Suter. All rights reserved.
+// </copyright>
+// <license>https://github.com/NSwag/NSwag/blob/master/LICENSE.md</license>
+// <author>Rico Suter, mail@rsuter.com</author>
+//-----------------------------------------------------------------------
+
+using Microsoft.Extensions.ApiDescription;
+using System;
+using System.IO;
+using System.Threading.Tasks;
+
+namespace NSwag.AspNetCore
+{
+    internal class SwaggerDocumentProvider : IDocumentProvider
+    {
+        private readonly IServiceProvider _serviceProvider;
+        private readonly SwaggerDocumentRegistry _registry;
+
+        public SwaggerDocumentProvider(IServiceProvider serviceProvider, SwaggerDocumentRegistry registry)
+        {
+            _serviceProvider = serviceProvider ?? throw new ArgumentNullException(nameof(serviceProvider));
+            _registry = registry ?? throw new ArgumentNullException(nameof(registry));
+        }
+
+        public async Task<SwaggerDocument> GenerateAsync(string documentName)
+        {
+            if (documentName == null)
+            {
+                throw new ArgumentNullException(nameof(documentName));
+            }
+
+            _registry.Documents.TryGetValue(documentName, out var settings);
+            if (settings == null)
+            {
+                throw new InvalidOperationException($"No registered OpenAPI/Swagger document found for document name '{documentName}'. " +
+                    $"Add with the AddSwagger()/AddOpenApi() methods in ConfigureServices().");
+            }
+
+            return await settings.GenerateAsync(_serviceProvider);
+        }
+
+        // Called by the Microsoft.Extensions.ApiDescription tool
+        async Task IDocumentProvider.GenerateAsync(string documentName, TextWriter writer)
+        {
+            if (documentName == null)
+            {
+                throw new ArgumentNullException(nameof(documentName));
+            }
+
+            if (writer == null)
+            {
+                throw new ArgumentNullException(nameof(writer));
+            }
+
+            var document = await GenerateAsync(documentName);
+
+            var json = document.ToJson();
+            await writer.WriteAsync(json);
+        }
+    }
+}

src/NSwag.AspNetCore/SwaggerDocumentRegistry.cs

@@ -0,0 +1,61 @@
+//-----------------------------------------------------------------------
+// <copyright file="DocumentRegistry.cs" company="NSwag">
+//     Copyright (c) Rico Suter. All rights reserved.
+// </copyright>
+// <license>https://github.com/NSwag/NSwag/blob/master/LICENSE.md</license>
+// <author>Rico Suter, mail@rsuter.com</author>
+//-----------------------------------------------------------------------
+
+using NSwag.SwaggerGeneration;
+using NSwag.SwaggerGeneration.AspNetCore;
+using System;
+using System.Collections.Generic;
+
+namespace NSwag.AspNetCore
+{
+    /// <summary>Registry with Swagger document generators.</summary>
+    public class SwaggerDocumentRegistry
+    {
+        private readonly Dictionary<string, ISwaggerGenerator> _documents;
+
+        /// <summary>Initializes a new instance of the <see cref="SwaggerDocumentRegistry"/> class.</summary>
+        public SwaggerDocumentRegistry()
+        {
+            _documents = new Dictionary<string, ISwaggerGenerator>(StringComparer.Ordinal);
+        }
+
+        /// <summary>Adds a document to the registry.</summary>
+        /// <param name="configure">The configure action.</param>
+        /// <returns>The registry.</returns>
+        public SwaggerDocumentRegistry AddDocument(Action<AspNetCoreToSwaggerGeneratorSettings> configure = null)
+        {
+            return AddDocument("v1", configure);
+        }
+
+        /// <summary>Adds a document to the registry.</summary>
+        /// <param name="documentName">The document name.</param>
+        /// <param name="configure">The configure action.</param>
+        /// <returns>The registry.</returns>
+        public SwaggerDocumentRegistry AddDocument(string documentName, Action<AspNetCoreToSwaggerGeneratorSettings> configure = null)
+        {
+            var settings = new AspNetCoreToSwaggerGeneratorSettings();
+            configure?.Invoke(settings);
+
+            var generator = new AspNetCoreToSwaggerGenerator(settings);
+            return AddDocument(documentName, generator);
+        }
+
+        /// <summary>Adds a document to the registry.</summary>
+        /// <param name="documentName">The document name.</param>
+        /// <param name="swaggerGenerator">The Swagger generator.</param>
+        /// <returns>The registry.</returns>
+        public SwaggerDocumentRegistry AddDocument(string documentName, ISwaggerGenerator swaggerGenerator)
+        {
+            _documents[documentName] = swaggerGenerator;
+            return this;
+        }
+
+        /// <summary>Gets a dictionary with all registered documents.</summary>
+        public IReadOnlyDictionary<string, ISwaggerGenerator> Documents => _documents;
+    }
+}