Merge pull request #19595 from abpframework/EngincanV-patch-1

Document "how to extend the application-configuration endpoint"

docs/en/API/Application-Configuration.md

@@ -1,6 +1,6 @@
 # Application Configuration Endpoint
 
-ABP Framework provides a pre-built and standard endpoint that contains some useful information about the application/service. Here, the list of some fundamental information at this endpoint:
+ABP Framework provides a pre-built and standard endpoint that contains some useful information about the application/service. Here, is the list of some fundamental information at this endpoint:
 
 * Granted [policies](../Authorization.md) (permissions) for the current user.
 * [Setting](../Settings.md) values for the current user.
@@ -22,3 +22,40 @@ See the [JavaScript API document](../UI/AspNetCore/JavaScript-API/Index.md) for
 
 Other UI types provide services native to the related platform. For example, see the [Angular UI settings documentation](../UI/Angular/Settings.md) to learn how to use the setting values exposes by this endpoint.
 
+## Extending the Endpoint
+
+The **application-configuration** endpoint contains some useful information about the application, such as _localization values_, _current user information_, _granted permissions_, etc. Even most of the time these provided values are sufficient to use in your application to perform common requirements such as getting the logged-in user's ID or its granted permissions. You may still want to extend this endpoint and provide additional information for your application/service. At that point, you can use the `IApplicationConfigurationContributor` endpoint.
+
+### IApplicationConfigurationContributor
+
+`IApplicationConfigurationContributor` is the interface that should be implemented to add additional information to the **application-configuration** endpoint.
+
+**Example: Setting the deployment version**
+
+```csharp
+using System.Threading.Tasks;
+using Volo.Abp.AspNetCore.Mvc.ApplicationConfigurations;
+using Volo.Abp.Data;
+
+namespace Acme.BookStore.Web
+{
+    public class MyApplicationConfigurationContributor : IApplicationConfigurationContributor
+    {
+        public Task ContributeAsync(ApplicationConfigurationContributorContext context)
+        {
+            //for simplicity, it's a static number, you can inject any service to this class and perform your logic...
+            var deploymentVersion = "v1.0.0"; 
+
+            //setting the deploymentVersion
+            context.ApplicationConfiguration.SetProperty("deploymentVersion", deploymentVersion);
+
+            return Task.CompletedTask;
+        }
+    }
+}
+```
+
+* `IApplicationConfigurationContributor` defines the `ContributeAsync` method to extend the **application-configuration** endpoint with the specified additional data.
+* You can inject services and perform any logic needed to extend the endpoint as you wish.
+
+> Application configuration contributors are automatically discovered by the ABP Framework and executed as a part of the application configuration initialization process.