Webapi Swagger Tutorial (dotnet#1768)

* structure

* wip, intial description and code examples

* 'space'

* screenshots and getting started

* basic complete, annotations started

* rename var, comment code

* complete through DataAnnotations

* customizing ui src

* custom html src complete - simple

* custom ui complete

* summary

* fix indent issue

* indentation issues

* editing changes

* adding .vscode user exclusions

* remove .vscode folder

* user files

* spell check

* reword testing method section

* added download link to intro

* edits for final review

* fix punctuation in controller

* add red boxes to swagger-ui image

* minor edits 

.gitignore

@@ -8,7 +8,7 @@ _build/
 *.user
 *.userosscache
 *.sln.docstates
-
+*.vscode/
 # User-specific files (MonoDevelop/Xamarin Studio)
 *.userprefs
 

aspnet/tutorials/index.rst

@@ -12,3 +12,4 @@ Tutorials
    ASP.NET Core and Azure Service Fabric <https://azure.microsoft.com/en-us/documentation/articles/service-fabric-add-a-web-frontend/>
    /mobile/native-mobile-backend
    dotnet-watch
+   web-api-help-pages-using-swagger

aspnet/tutorials/web-api-help-pages-using-swagger.rst

@@ -0,0 +1,377 @@
+.. _web-api-help-pages-using-swagger:
+
+ASP.NET Web API Help Pages using Swagger
+========================================
+
+By `Shayne Boyer`_
+
+Understanding the various methods of an API can be a challenge for a developer when building a consuming application. 
+
+Generating good documentation and help pages as a part of your Web API using `Swagger <a href="http://swagger.io/">`_ with the .NET Core implementation `Swashbuckle <a href="https://github.com/domaindrivendev/Ahoy">`_ is as easy as adding a couple of NuGet packages and modifying the *Startup.cs*. 
+
+- `Swashbuckle <a href="https://github.com/domaindrivendev/Ahoy">`_ is an open source project for generating Swagger documents for Web APIs and built with ASP.NET Core MVC. 
+
+- `Swagger <a href="http://swagger.io/">`_ is a machine readable representation of a RESTful API that enables support for interactive documentation, client SDK generation and discoverability.
+
+This tutorial builds on the sample on :doc:`first-web-api`. If you'd like to follow along, download the sample at https://github.com/aspnet/Docs/tree/master/aspnet/tutorials/first-web-api/sample.
+
+.. contents:: Sections:
+  :local:
+  :depth: 2
+
+Getting Started
+---------------
+There are two core components to Swashbuckle 
+
+- *Swashbuckle.SwaggerGen* : provides the functionality to scaffold your Web API and generate JSON Swagger documents that describe the objects, methods, return types, etc. 
+- *Swashbuckle.SwaggerUI* : an embedded version of the Swagger UI tool which uses the above documents for a rich customizable experience for describing the Web API functionality and includes built in test harness capabilities for the public methods.
+
+NuGet Packages
+--------------
+You can add Swashbuckle with any of the following approaches:
+
+- From the Package Manager Console: 
+
+.. code-block:: bash
+
+    Install-Package Swashbuckle -Pre
+
+- Add Swashbuckle to *project.json*:
+
+.. code-block:: javascript
+
+    "Swashbuckle": "6.0.0-*"
+
+- In Visual Studio:
+	- Right click your project in Solution Explorer > Manage NuGet Packages 
+	- Enter Swashbuckle in the search box
+	- Check "Include prerelease" 
+	- Set the Package source to nuget.org 
+	- Tap the Swashbuckle package and then tap Install 
+
+
+
+Add and configure Swagger to the middleware
+-------------------------------------------
+
+Add SwaggerGen to the services collection in the Configure method, and in the ConfigureServices method, enable the middleware for serving generated JSON document and the SwaggerUI. 
+
+.. code-block:: c#
+  :emphasize-lines: 12,21,24
+
+    public void ConfigureServices(IServiceCollection services)
+    {
+        // Add framework services.
+        services.AddMvc();
+
+        services.AddLogging();
+
+        // Add our repository type
+        services.AddSingleton<ITodoRepository, TodoRepository>();
+
+        // Inject an implementation of ISwaggerProvider with defaulted settings applied
+        services.AddSwaggerGen();
+    }
+
+    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
+    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
+    {
+        app.UseMvcWithDefaultRoute();
+
+        // Enable middleware to serve generated Swagger as a JSON endpoint
+        app.UseSwagger();
+
+        // Enable middleware to serve swagger-ui assets (HTML, JS, CSS etc.)
+        app.UseSwaggerUi();
+        
+    }
+
+
+In Visual Studio, press ^F5 to launch the app and navigate to ``http://localhost:<random_port>/swagger/v1/swagger.json`` to see the document generated that describes the endpoints. 
+
+.. note:: Microsoft Edge, Google Chrome and Firefox display JSON documents natively.  There are extensions for Chrome that will format the document for easier reading. *Example below reduced for brevity.*
+
+.. code-block:: javascript
+
+    {
+    "swagger": "2.0",
+    "info": {
+        "version": "v1",
+        "title": "API V1"
+    },
+    "basePath": "/",
+    "paths": {
+        "/api/Todo": {
+        "get": {
+            "tags": [
+            "Todo"
+            ],
+            "operationId": "ApiTodoGet",
+            "consumes": [],
+            "produces": [
+            "text/plain",
+            "application/json",
+            "text/json"
+            ],
+            "responses": {
+            "200": {
+                "description": "OK",
+                "schema": {
+                "type": "array",
+                "items": {
+                    "$ref": "#/definitions/TodoItem"
+                }
+                }
+            }
+            },
+            "deprecated": false
+        },
+        "post": {
+            ...
+        }
+        },
+        "/api/Todo/{id}": {
+        "get": {
+            ...
+        },
+        "put": {
+            ...
+        },
+        "delete": {
+            ...
+    },
+    "definitions": {
+        "TodoItem": {
+        "type": "object",
+        "properties": {
+            "key": {
+            "type": "string"
+            },
+            "name": {
+            "type": "string"
+            },
+            "isComplete": {
+            "type": "boolean"
+            }
+        }
+        }
+    },
+    "securityDefinitions": {}
+    }
+
+This document is used to drive the Swagger UI which can be viewed by navigating to ``http://localhost:<random_port>/swagger/ui``
+
+.. image:: web-api-help-pages-using-swagger/_static/swagger-ui.png
+
+Each of the methods in the ToDo controller can be tested from the UI. Tap a method to expand the section, add any necessary parameters and tap "Try it out!".
+
+.. image:: web-api-help-pages-using-swagger/_static/get-try-it-out.png
+
+
+Customization & Extensibility 
+-----------------------------
+Swagger is not only a simple way to represent the API, but has options for documenting the object model, as well as customizing the interactive UI to match your look and feel or design language.
+
+API Info and Description
+''''''''''''''''''''''''
+The ``ConfigureSwaggerGen`` method can be used to add information such as the author, license, description.
+
+.. code-block:: c#
+    
+    services.ConfigureSwaggerGen(options =>
+    {
+        options.SingleApiVersion(new Info
+        {
+            Version = "v1",
+            Title = "ToDo API",
+            Description = "A simple example ASP.NET Core Web API",
+            TermsOfService = "None",
+            Contact = new Contact { Name = "Shayne Boyer", Email = "", Url = "http://twitter.com/spboyer"},
+            License = new License { Name = "Use under LICX", Url = "http://url.com" }
+        });
+    });
+
+The following image shows the Swagger UI displaying the version information added.
+
+.. image:: web-api-help-pages-using-swagger/_static/custom-info.png
+
+XML Comments
+'''''''''''''
+To enable XML comments, right click the project in Visual Studio and select **Properties** and then check the **XML Documentation file** box under the **Output Settings** section.
+
+.. image:: web-api-help-pages-using-swagger/_static/swagger-xml-comments.png 
+    :scale: 75%
+
+Alternatively, you can enable XML comments by setting `"xmlDoc": true` in *project.json*.
+
+.. code-block:: javascript
+    :emphasize-lines: 4
+        
+    "buildOptions": {
+        "emitEntryPoint": true,
+        "preserveCompilationContext": true,
+        "xmlDoc": true
+    },
+
+Configure Swagger to use the generated XML file.
+
+.. note:: For Linux or non-Windows operating systems, file names and paths can be case sensitive. So ``ToDoApi.XML`` would be found on Windows but not CentOS for example.
+
+.. literalinclude:: web-api-help-pages-using-swagger/sample/src/TodoApi/Startup.cs
+    :language: c#
+    :start-after: snippet_Configure
+    :end-before: #endregion
+    :dedent: 8
+    :emphasize-lines: 29,32
+
+In the code above, ApplicationBasePath gets the base path of the app, which is needed to set the full path to the XML comments. ``TodoApi.xml`` only works for this example, the name of the generated XML comments file is based on the name of your application. 
+
+Adding the triple slash comments to the method enhances the Swagger UI by adding the description to the header of the section.
+
+.. literalinclude:: web-api-help-pages-using-swagger/sample/src/TodoApi/Controllers/TodoController.cs
+    :language: c#
+    :start-after: Delete_Method
+    :end-before: #endregion
+    :dedent: 8
+    :emphasize-lines: 2
+
+.. image:: web-api-help-pages-using-swagger/_static/triple-slash-comments.png
+
+Note that the UI is driven by the generated JSON file, and these comments are also in that file as well.
+
+.. code-block:: javascript
+    :emphasize-lines: 5
+
+      "delete": {
+        "tags": [
+          "Todo"
+        ],
+        "summary": "Deletes a specific TodoItem",
+        "operationId": "ApiTodoByIdDelete",
+        "consumes": [],
+        "produces": [],
+        "parameters": [
+          {
+            "name": "id",
+            "in": "path",
+            "description": "",
+            "required": true,
+            "type": "string"
+          }
+        ],
+        "responses": {
+          "204": {
+            "description": "No Content"
+          }
+        },
+        "deprecated": false
+      }
+
+Here is a more robust example, adding ``<remarks />`` where the content can be just text or adding the JSON or XML object for further documentation of the method.
+
+.. literalinclude:: web-api-help-pages-using-swagger/sample/src/TodoApi/Controllers/TodoController.cs
+    :language: c#
+    :start-after: Create_Method
+    :end-before: #endregion
+    :dedent: 8
+    :emphasize-lines: 4-14
+
+Notice the enhancement of the UI with these additional comments.
+
+.. image:: web-api-help-pages-using-swagger/_static/xml-comments-extended.png
+
+
+DataAnnotations
+'''''''''''''''
+You can decorate the API controller with ``System.ComponentModel.DataAnnotations`` to help drive the Swagger UI components.
+
+Adding the ``[Required]`` annotation to the ``Name`` property of the TodoItem class will change the ModelSchema information in the UI. ``[Produces("application/json"]``, RegularExpression validators and more will further detail the information delivered in the generated page.  The more metadata that is in the code produces a more desciptive UI or API help page. 
+
+
+.. literalinclude:: web-api-help-pages-using-swagger/sample/src/TodoApi/Models/TodoItem.cs
+  :language: c#
+  :emphasize-lines: 10
+
+
+Describing Response Types
+'''''''''''''''''''''''''
+Consuming developers are probably most concerned with what is returned; specifically response types, error codes (if not standard). These are handled in the XML comments and DataAnnotations.
+
+Take the ``Create()`` method for example, currently it returns only "201 Created" response by default. That is of course if the item is in fact created, or a "204 No Content" if no data is passed in the POST Body.  However, there is no documentation to know that or any other response. That can be fixed by adding the following piece of code.
+
+
+.. literalinclude:: web-api-help-pages-using-swagger/sample/src/TodoApi/Controllers/TodoController.cs
+    :language: c#
+    :start-after: Create_Method
+    :end-before: #endregion
+    :dedent: 8
+    :emphasize-lines: 17,18,20,21
+
+.. image:: web-api-help-pages-using-swagger/_static/data-annotations-response-types.png
+
+Customizing the UI
+''''''''''''''''''
+The stock UI is very functional as well as presentable, however when building documentation pages for your API you want it to represent your brand or look and feel. 
+
+Accomplishing that task with the Swashbuckle components is simple but requires adding the resources to serve static files that would not normally be included in a Web API project and then building the folder structure to host those files.
+
+Add the ``"Microsoft.AspNetCore.StaticFiles": "1.0.0-*"`` NuGet package to the project.
+
+Enable static files middleware.
+
+.. code-block:: c#
+    :emphasize-lines: 4
+
+    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
+    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
+    {
+        app.UseStaticFiles();
+
+        app.UseMvcWithDefaultRoute();
+
+        // Enable middleware to serve generated Swagger as a JSON endpoint
+        app.UseSwagger();
+
+        // Enable middleware to serve swagger-ui assets (HTML, JS, CSS etc.)
+        app.UseSwaggerUi();
+        
+    }
+
+Acquire the core *index.html* file used for the Swagger UI page from the `Github repository <https://github.com/swagger-api/swagger-ui/blob/master/src/main/html/index.html>`_ and put that in the ``wwwroot/swagger/ui`` folder and also create a new ``custom.css`` file in the same folder.
+
+.. image:: web-api-help-pages-using-swagger/_static/custom-files-folder-view.png
+    :scale: 80%
+
+Reference *custom.css* in the *index.html* file. 
+
+.. code-block:: html
+
+    <link href='custom.css' media='screen' rel='stylesheet' type='text/css' />
+
+The following CSS provides a simple sample of a custom header title to the page.
+
+*custom.css file*
+
+.. literalinclude:: web-api-help-pages-using-swagger/sample/src/TodoApi/wwwroot/swagger/ui/custom.css
+  :language: css
+
+*index.html body*
+
+.. code-block:: html
+
+    <body class="swagger-section">
+       <div id="header">
+        <h1>ToDo API Documentation</h1>
+       </div>
+    
+       <div id="message-bar" class="swagger-ui-wrap" data-sw-translate>&nbsp;</div>
+       <div id="swagger-ui-container" class="swagger-ui-wrap"></div>
+    </body>
+    
+
+.. image:: web-api-help-pages-using-swagger/_static/custom-header.png
+
+There is much more you can do with the page, see the full capabilities for the UI resources at the `Swagger UI Github repository <a href="https://github.com/swagger-api/swagger-ui">`_. 
+
+
+