Merge branch 'master' of https://github.com/volosoft/abp

docs/en/AspNetCore/Dynamic-CSharp-API-Clients.md

@@ -0,0 +1,153 @@
+# Dynamic C# API Clients
+
+ABP can dynamically create C# API client proxies to call remote HTTP services (REST APIs). In this way, you don't need to deal with `HttpClient` and other low level HTTP features to call remote services and get results.
+
+## Service Interface
+
+Your service/controller should implement an interface that is shared between the server and the client. So, first define a service interface in a shared library project. Example:
+
+````csharp
+public interface IBookService : IApplicationService
+{
+    Task<List<BookDto>> GetListAsync();
+}
+````
+
+Your interface should implement the `IRemoteService` interface. Since the `IApplicationService` inherits the `IRemoteService` interface, the `IBookService` above satisfies this condition.
+
+Implement this class in your service application. You can use [auto API controller system](Auto-API-Controllers.md) to expose the service as a REST API endpoint.
+
+## Client Proxy Generation
+
+First, add [Volo.Abp.Http.Client](https://www.nuget.org/packages/Volo.Abp.Http.Client) nuget package to your client project:
+
+````
+Install-Package Volo.Abp.Http.Client
+````
+
+Then add `AbpHttpClientModule` dependency to your module:
+
+````csharp
+[DependsOn(typeof(AbpHttpClientModule))] //add the dependency
+public class MyClientAppModule : AbpModule
+{
+}
+````
+
+Now, it's ready to create the client proxies. Example:
+
+````csharp
+[DependsOn(
+    typeof(AbpHttpClientModule), //used to create client proxies
+    typeof(BookStoreApplicationModule) //contains the application service interfaces
+    )]
+public class MyClientAppModule : AbpModule
+{
+    public override void ConfigureServices(ServiceConfigurationContext context)
+    {
+        //Configure remote end point
+        context.Services.Configure<RemoteServiceOptions>(options =>
+        {
+            options.RemoteServices.Default =
+                new RemoteServiceConfiguration("http://localhost:53929/");
+        });
+
+        //Create dynamic client proxies
+        context.Services.AddHttpClientProxies(
+            typeof(BookStoreApplicationModule).Assembly
+        );
+    }
+}
+````
+
+`RemoteServiceOptions` is used to configure endpoints for remote services (This example sets the default endpoint while you can have different service endpoints used by different clients. See the "Multiple Remote Service Endpoint" section).
+
+`AddHttpClientProxies` method gets an assembly, finds all service interfaces in the given assembly, creates and registers proxy classes.
+
+## Usage
+
+It's straightforward to use. Just inject the service interface in the client application code:
+
+````csharp
+public class MyService : ITransientDependency
+{
+    private readonly IBookService _bookService;
+
+    public MyService(IBookService bookService)
+    {
+        _bookService = bookService;
+    }
+
+    public async Task DoIt()
+    {
+        var books = await _bookService.GetListAsync();
+        foreach (var book in books)
+        {
+            Console.WriteLine($"[BOOK {book.Id}] Name={book.Name}");
+        }
+    }
+}
+````
+
+This sample injects the `IBookService` service interface defined above. The dynamic client proxy implementation makes an HTTP call whenever a service method is called by the client.
+
+## Configuration Details
+
+### RemoteServiceOptions
+
+While you can configure `RemoteServiceOptions` as the example shown above, you can let it to read from your `appsettings.json` file. Add a `RemoteServices` section to your `appsettings.json` file:
+
+````json
+{
+  "RemoteServices": {
+    "Default": {
+      "BaseUrl": "http://localhost:53929/"
+    } 
+  } 
+}
+````
+
+Then you can pass your `IConfigurationRoot` instance directly to the `Configure<RemoteServiceOptions>()` method as shown below:
+
+````csharp
+var configuration = new ConfigurationBuilder()
+    .SetBasePath(Directory.GetCurrentDirectory())
+    .AddJsonFile("appsettings.json")
+    .Build();
+
+context.Services.Configure<RemoteServiceOptions>(configuration);
+````
+
+This approach is useful since it's easy to change the configuration later without touching to the code.
+
+#### Multiple Remote Service Endpoint
+
+The examples above have configured the "Default" remote service endpoint. You may have different endpoints for different services (as like in a microservice approach where each microservice has different endpoint). In this case, you can add other endpoints to your configuration file:
+
+````json
+{
+  "RemoteServices": {
+    "Default": {
+      "BaseUrl": "http://localhost:53929/"
+    },
+    "BookStore": {
+      "BaseUrl": "http://localhost:48392/"
+    } 
+  } 
+}
+````
+
+See the next section to learn how to use this new endpoint.
+
+### AddHttpClientProxies Method
+
+`AddHttpClientProxies` method can get an additional parameter for the remote service name. Example:
+
+````csharp
+context.Services.AddHttpClientProxies(
+    typeof(BookStoreApplicationModule).Assembly,
+    remoteServiceName: "BookStore"
+);
+````
+
+`remoteServiceName` parameter matches the service endpoint configured via `RemoteServiceOptions`. If the `BookStore` endpoint is not defined then it fallbacks to the `Default` endpoint.

docs/en/docs-nav.json

@@ -194,6 +194,10 @@
             {
               "text": "Auto API Controllers",
               "path": "AspNetCore/Auto-API-Controllers.md"
+            },
+            {
+              "text": "Dynamic C# API Clients",
+              "path": "AspNetCore/Dynamic-CSharp-API-Clients.md"
             }
           ]
         },

samples/BookStore/test/Acme.BookStore.ConsoleApiClient/Acme.BookStore.ConsoleApiClient.csproj

@@ -8,7 +8,14 @@
   <ItemGroup>
     <PackageReference Include="Volo.Abp.Autofac" Version="0.8.0" />
     <PackageReference Include="Volo.Abp.Http.Client" Version="0.8.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="2.1.1" />
     <ProjectReference Include="..\..\src\Acme.BookStore.Application\Acme.BookStore.Application.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <None Update="appsettings.json">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
 </Project>

samples/BookStore/test/Acme.BookStore.ConsoleApiClient/ApiClientDemoService.cs

@@ -16,6 +16,7 @@ namespace Acme.BookStore.ConsoleApiClient
 
         public async Task RunAsync()
         {
+            //While it seems like a regular method call, it actually calls a remote REST API.
             var output = await _bookAppService.GetListAsync(new PagedAndSortedResultRequestDto());
             foreach (var bookDto in output.Items)
             {

samples/BookStore/test/Acme.BookStore.ConsoleApiClient/ConsoleApiClientModule.cs

@@ -1,4 +1,6 @@
-using Microsoft.Extensions.DependencyInjection;
+using System.IO;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
 using Volo.Abp.Autofac;
 using Volo.Abp.Http.Client;
 using Volo.Abp.Modularity;
@@ -14,10 +16,12 @@ namespace Acme.BookStore.ConsoleApiClient
     {
         public override void ConfigureServices(ServiceConfigurationContext context)
         {
-            context.Services.Configure<RemoteServiceOptions>(options =>
-            {
-                options.RemoteServices.Default = new RemoteServiceConfiguration("http://localhost:53929/");
-            });
+            var configuration = new ConfigurationBuilder()
+                .SetBasePath(Directory.GetCurrentDirectory())
+                .AddJsonFile("appsettings.json")
+                .Build();
+
+            context.Services.Configure<RemoteServiceOptions>(configuration);
 
             context.Services.AddHttpClientProxies(
                 typeof(BookStoreApplicationModule).Assembly

samples/BookStore/test/Acme.BookStore.ConsoleApiClient/Program.cs

@@ -5,6 +5,8 @@ using Volo.Abp.Threading;
 
 namespace Acme.BookStore.ConsoleApiClient
 {
+    /* Before running this application, ensure that the Acme.BookStore.Web application is running.
+     */
     class Program
     {
         static void Main(string[] args)

samples/BookStore/test/Acme.BookStore.ConsoleApiClient/appsettings.json

@@ -0,0 +1,7 @@
+{
+  "RemoteServices": {
+    "Default": {
+      "BaseUrl": "http://localhost:53929/"
+    } 
+  } 
+}