dotnet tutorial kiota dependency injection

OpenAPI/kiota/toc.yml

@@ -77,5 +77,7 @@
   items:
   - name: Add an API to search
     href: add-api.md
+  - name: Use Kiota with Dependency Injection in .NET
+    href: tutorials/dotnet-dependencyinjection.md
 - name: Support
   href: support.md

OpenAPI/kiota/tutorials/dotnet-azure.md

@@ -14,6 +14,7 @@ In this tutorial, you will generate an API client that uses [Microsoft identity
 ## Required tools
 
 - [.NET SDK 8.0](https://get.dot.net/8)
+- [Kiota CLI](/openapi/kiota/install?tabs=bash&wt.mc_id=SEC-MVP-5004985#install-as-net-tool)
 
 ## Create a project
 
@@ -26,7 +27,7 @@ dotnet new gitignore
 
 ## Add dependencies
 
-Before you can compile and run the generated API client, you will need to make sure the generated source files are part of a project with the required dependencies. Your project must have a reference to the [abstraction package](https://github.com/microsoft/kiota-abstractions-dotnet). Additionally, you must either use the Kiota default implementations or provide your own custom implementations of of the following packages.
+Before you can compile and run the generated API client, you will need to make sure the generated source files are part of a project with the required dependencies. Your project must have a reference to the [abstraction package](https://github.com/microsoft/kiota-abstractions-dotnet). Additionally, you must either use the Kiota default implementations or provide your own custom implementations of the following packages.
 
 - Authentication ([Kiota default Azure authentication](https://github.com/microsoft/kiota-authentication-azure-dotnet))
 - HTTP ([Kiota default HttpClient-based implementation](https://github.com/microsoft/kiota-http-dotnet))

OpenAPI/kiota/tutorials/dotnet-dependencyinjection.md

@@ -0,0 +1,288 @@
+---
+title: Use Kiota with dependency injection in .NET
+description: Learn how you can combine Kiota with dependency injection in .NET to build API clients.
+author: svrooij
+ms.author: vibiret
+ms.topic: tutorial
+date: 05/10/2024
+---
+
+# Register a Kiota API client in .NET with dependency injection
+
+In this tutorial, you will learn how to register a [Kiota API client](/openapi/kiota/tutorials/dotnet-azure?wt.mc_id=SEC-MVP-5004985) with [dependency injection](/dotnet/core/extensions/dependency-injection-usage?wt.mc_id=SEC-MVP-5004985).
+
+## Required tools
+
+- [.NET SDK 8.0](https://get.dot.net/8)
+- [Kiota CLI](/openapi/kiota/install?tabs=bash&wt.mc_id=SEC-MVP-5004985#install-as-net-tool)
+
+## Create a project
+
+Run the following command in the directory you want to create a new project.
+
+```dotnetcli
+dotnet new webapi -o kiota-with-di
+cd kiota-with-di
+dotnet new gitignore
+```
+
+## Add dependencies
+
+Before you can compile and run the generated API client, you will need to make sure the generated source files are part of a project with the required dependencies. Your project must have a reference to the [abstraction package](https://github.com/microsoft/kiota-abstractions-dotnet) and some default implementations.
+
+- HTTP ([Kiota default HttpClient-based implementation](https://github.com/microsoft/kiota-http-dotnet))
+- JSON serialization ([Kiota default](https://github.com/microsoft/kiota-serialization-json-dotnet))
+- HttpClient support for Dependency Injection [Microsoft.Extensions.Http](https://www.nuget.org/packages/Microsoft.Extensions.Http)
+
+If you expect to use other serialization formats, you can add the following packages.
+
+- Form serialization ([Kiota default](https://github.com/microsoft/kiota-serialization-form-dotnet))
+- Text serialization ([Kiota default](https://github.com/microsoft/kiota-serialization-text-dotnet))
+- Multipart serialization ([Kiota default](https://github.com/microsoft/kiota-serialization-multipart-dotnet))
+
+Run the following commands to get the required dependencies.
+
+```dotnetcli
+dotnet add package Microsoft.Extensions.Http
+dotnet add package Microsoft.Kiota.Abstractions
+dotnet add package Microsoft.Kiota.Http.HttpClientLibrary
+dotnet add package Microsoft.Kiota.Serialization.Json
+
+# Uncomment the following lines if you expect to use other serialization formats
+# dotnet add package Microsoft.Kiota.Serialization.Form
+# dotnet add package Microsoft.Kiota.Serialization.Text
+# dotnet add package Microsoft.Kiota.Serialization.Multipart
+```
+
+## Generate the API client
+
+Kiota generates API clients from OpenAPI documents. Create a file named _github-releases.yml_ and add the following.
+
+```yaml
+openapi: 3.0.3
+info:
+  title: GitHub Release API
+  version: 1.0.0
+servers:
+  - url: https://api.github.com
+    description: GitHub API
+    variables:
+      version:
+        default: '2022-11-28'
+        description: GitHub API version
+paths:
+  /repos/{owner}/{repo}/releases/latest:
+    get:
+      summary: Get the latest release
+      parameters:
+        - name: owner
+          in: path
+          required: true
+          description: The owner of the repository
+          schema:
+            type: string
+        - name: repo
+          in: path
+          required: true
+          description: The repository name
+          schema:
+            type: string
+      responses:
+        200:
+          description: Success!
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/github.release"
+        404:
+          description: Not found
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/github.error"
+
+components:
+  schemas:
+    github.release:
+      type: object
+      properties:
+        id:
+          type: integer
+          description: The release ID
+        tag_name:
+          type: string
+          description: The release tag name
+        name:
+          type: string
+          description: The release name
+        body:
+          type: string
+          description: The release body
+        created_at:
+          type: string
+          format: date-time
+          description: The release creation date
+        published_at:
+          type: string
+          format: date-time
+          description: The release publication date
+    github.error:
+      type: object
+      properties:
+        message:
+          type: string
+          description: The error message
+        documentation_url:
+          type: string
+          description: The error documentation URL
+```
+
+You can then use the [Kiota](/openapi/kiota/install?tabs=bash&wt.mc_id=SEC-MVP-5004985#install-as-net-tool) command line tool to generate the API client classes. We are using the [deserializer](/openapi/kiota/using#--deserializer---ds) and [serializer](/openapi/kiota/using#--serializer---s) options to specify the serialization format, to only use JSON serialization.
+
+```bash
+kiota generate -l csharp -d github-releases.yml -c GitHubClient -n GitHub.ApiClient -o ./GitHub --deserializer Microsoft.Kiota.Serialization.Json.JsonParseNodeFactory --serializer Microsoft.Kiota.Serialization.Json.JsonSerializationWriterFactory
+```
+
+## Create extension methods
+
+Create a new file named _KiotaServiceCollectionExtensions.cs_ in the root of your project and add the following code.
+
+```csharp
+using Microsoft.Kiota.Http.HttpClientLibrary.Middleware;
+using Microsoft.Kiota.Http.HttpClientLibrary.Middleware.Options;
+
+/// <summary>
+/// Service collection extensions for Kiota handlers.
+/// </summary>
+public static class KiotaServiceCollectionExtensions
+{
+    /// <summary>
+    /// Adds the Kiota handlers to the service collection.
+    /// </summary>
+    /// <param name="services"><see cref="IServiceCollection"/> to add the services to</param>
+    /// <returns><see cref="IServiceCollection"/> as per convention</returns>
+    /// <remarks>The handlers are added to the http client by the <see cref="AttachKiotaHandlers(IHttpClientBuilder)"/> call, which requires them to be pre-registered in DI</remarks>
+    public static IServiceCollection AddKiotaHandlers(this IServiceCollection services)
+    {
+        services.AddTransient<UriReplacementHandler<UriReplacementHandlerOption>>();
+        services.AddTransient<RetryHandler>();
+        services.AddTransient<RedirectHandler>();
+        services.AddTransient<ParametersNameDecodingHandler>();
+        services.AddTransient<UserAgentHandler>();
+        services.AddTransient<HeadersInspectionHandler>();
+        return services;
+    }
+
+    /// <summary>
+    /// Adds the Kiota handlers to the http client builder.
+    /// </summary>
+    /// <param name="builder"></param>
+    /// <returns></returns>
+    /// <remarks>
+    /// Requires the handlers to be registered in DI by <see cref="AddKiotaHandlers(IServiceCollection)"/>.
+    /// The order in which the handlers are added is important, as it defines the order in which they will be executed.
+    /// <see href="https://github.com/microsoft/kiota-http-dotnet/blob/c1c295d3b0ebb2182b66d9a6858241117b59b540/src/KiotaClientFactory.cs#L50-L62">KiotaClientFactory.cs</see> for the default order.
+    /// </remarks>
+    public static IHttpClientBuilder AttachKiotaHandlers(this IHttpClientBuilder builder)
+    {
+        builder.AddHttpMessageHandler<UriReplacementHandler<UriReplacementHandlerOption>>();
+        builder.AddHttpMessageHandler<RetryHandler>();
+        builder.AddHttpMessageHandler<RedirectHandler>();
+        builder.AddHttpMessageHandler<ParametersNameDecodingHandler>();
+        builder.AddHttpMessageHandler<UserAgentHandler>();
+        builder.AddHttpMessageHandler<HeadersInspectionHandler>();
+        return builder;
+    }
+}
+```
+
+## Create a client factory
+
+Create a new file named _GitHubClientFactory.cs_ in the _GitHub_ folder and add the following code.
+
+This is what you call a factory pattern, where you create a factory class that is responsible for creating an instance of the client. This way you have a single place that is responsible for creating the client, and you can easily change the way the client is created. In this sample we will be registering the factory in the dependency injection container as well, because it will get the `HttpClient` injected in the constructor.
+
+```csharp
+using GitHub.ApiClient;
+using Microsoft.Kiota.Abstractions.Authentication;
+using Microsoft.Kiota.Http.HttpClientLibrary;
+
+namespace GitHub;
+
+public class GitHubClientFactory
+{
+    private readonly IAuthenticationProvider _authenticationProvider;
+    private readonly HttpClient _httpClient;
+
+    public GitHubClientFactory(HttpClient httpClient)
+    {
+        _authenticationProvider = new AnonymousAuthenticationProvider();
+        _httpClient = httpClient;
+    }
+
+    public GitHubClient GetClient() {
+      return new GitHubClient(new HttpClientRequestAdapter(_authenticationProvider, httpClient: _httpClient));
+    }
+}
+```
+
+## Register the API client
+
+Open the _Program.cs_ file and add the following code above the `var app = builder.Build();` line.
+
+```csharp
+using GitHub;
+...
+
+// Add Kiota handlers to the DI container
+builder.Services.AddKiotaHandlers();
+
+// Register the factory for the GitHub client
+builder.Services.AddHttpClient<GitHubClientFactory>((sp, client) => {
+    client.BaseAddress = new Uri("https://api.github.com");
+    client.DefaultRequestHeaders.Add("Accept", "application/vnd.github.v3+json");
+}).AttachKiotaHandlers();
+
+// Register the GitHub client
+builder.Services.AddTransient(sp=> sp.GetRequiredService<GitHubClientFactory>().GetClient());
+```
+
+## Create an endpoint
+
+We will now create an endpoint that uses the GitHub client from dependency injection to get the latest release of `dotnet/runtime`.
+
+Open the _Program.cs_ file and add the following code above the `app.Run();` line.
+
+```csharp
+app.MapGet("/dotnet/releases", async (GitHub.ApiClient.GitHubClient client, CancellationToken cancellationToken) =>
+{
+    var releases = await client.Repos["dotnet"]["runtime"].Releases.Latest.GetAsync(cancellationToken: cancellationToken);
+    return releases;
+})
+.WithName("GetDotnetReleases")
+.WithOpenApi();
+```
+
+## Run the application
+
+Run the following command in your project directory to start the application.
+
+```dotnetcli
+dotnet run
+```
+
+You can now open a browser and navigate to `http://localhost:{port}/dotnet/releases` to see the latest release of `dotnet/runtime`. Alternatively, you can also go to `http://localhost:{port}/swagger` to see the Swagger UI with this new endpoint.
+
+## Authentication
+
+The `GitHubClientFactory` class is responsible for creating the client, and it is also responsible for creating the `IAuthenticationProvider`. In this sample, we are using the `AnonymousAuthenticationProvider`, which is a simple provider that does not add any authentication headers. More details on authentication with Kiota can be found in the [Kiota authentication documentation](/openapi/kiota/authentication?wt.mc_id=SEC-MVP-5004985).
+
+What to remember is that the `GitHubClientFactory` is used through dependency injection, which means you can have other types injected by the constructor that are needed for the authentication provider.
+
+In [this example](https://github.com/svrooij/KiotaWithDependencyInjection/blob/d1ee972e8ba06c4f9707b78dfa981f5f57fbf7e6/KiotaWithDependencyInjection/Spotify/SpotifyFactory.cs) there is an `IAccessTokenProvider` injected that is then [used](https://github.com/svrooij/KiotaWithDependencyInjection/blob/d1ee972e8ba06c4f9707b78dfa981f5f57fbf7e6/KiotaWithDependencyInjection/Spotify/SpotifyFactory.cs#L36) for the [BaseBearerTokenAuthenticationProvider](/openapi/kiota/authentication?tabs=csharp&wt.mc_id=SEC-MVP-5004985#base-bearer-token-authentication-provider) that is available in Kiota.
+
+## See also
+
+- [KiotaWithDependencyInjection repository](https://github.com/svrooij/KiotaWithDependencyInjection) contains the code that inspired this tutorial.
+- [Build API clients for .NET with Microsoft Identity authentication](/openapi/kiota/tutorials/dotnet-azure?wt.mc_id=SEC-MVP-5004985) shows how to use Kiota with Microsoft Identity authentication.
+- [ToDoItem Sample API](https://github.com/microsoft/kiota-samples/tree/main/sample-api) implements a sample OpenAPI in ASP.NET Core and sample clients in multiple languages.