Add project files.

src/common/Elsa.Api.Common/Extensions/WebApplicationExtensions.cs

@@ -0,0 +1,75 @@
+using System.Globalization;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Elsa.Workflows;
+using FastEndpoints;
+using JetBrains.Annotations;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.Extensions.DependencyInjection;
+
+// ReSharper disable once CheckNamespace
+namespace Elsa.Extensions;
+
+/// <summary>
+/// Provides extension methods to add the FastEndpoints middleware configured for use with Elsa API endpoints. 
+/// </summary>
+[PublicAPI]
+public static class WebApplicationExtensions
+{
+    /// <summary>
+    /// Register the FastEndpoints middleware configured for use with with Elsa API endpoints.
+    /// </summary>
+    /// <param name="app"></param>
+    /// <param name="routePrefix">The route prefix to apply to Elsa API endpoints.</param>
+    /// <example>E.g. "elsa/api" will expose endpoints like this: "/elsa/api/workflow-definitions"</example>
+    public static IApplicationBuilder UseWorkflowsApi(this IApplicationBuilder app, string routePrefix = "elsa/api")
+    {
+        return app.UseFastEndpoints(config =>
+        {
+            config.Endpoints.RoutePrefix = routePrefix;
+            config.Serializer.RequestDeserializer = DeserializeRequestAsync;
+            config.Serializer.ResponseSerializer = SerializeRequestAsync;
+
+            config.Binding.ValueParserFor<DateTimeOffset>(s =>
+                new(DateTimeOffset.TryParse(s.ToString(), CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out var result), result));
+        });
+    }
+
+    /// <summary>
+    /// Register the FastEndpoints middleware configured for use with with Elsa API endpoints.
+    /// </summary>
+    /// <param name="routes">The <see cref="IEndpointRouteBuilder"/> to register the endpoints with.</param>
+    /// <param name="routePrefix">The route prefix to apply to Elsa API endpoints.</param>
+    /// <example>E.g. "elsa/api" will expose endpoints like this: "/elsa/api/workflow-definitions"</example>
+    public static IEndpointRouteBuilder MapWorkflowsApi(this IEndpointRouteBuilder routes, string routePrefix = "elsa/api") =>
+        routes.MapFastEndpoints(config =>
+        {
+            config.Endpoints.RoutePrefix = routePrefix;
+            config.Serializer.RequestDeserializer = DeserializeRequestAsync;
+            config.Serializer.ResponseSerializer = SerializeRequestAsync;
+        });
+
+    private static ValueTask<object?> DeserializeRequestAsync(HttpRequest httpRequest, Type modelType, JsonSerializerContext? serializerContext, CancellationToken cancellationToken)
+    {
+        var serializer = httpRequest.HttpContext.RequestServices.GetRequiredService<IApiSerializer>();
+        var options = serializer.GetOptions();
+
+        return serializerContext == null
+            ? JsonSerializer.DeserializeAsync(httpRequest.Body, modelType, options, cancellationToken)
+            : JsonSerializer.DeserializeAsync(httpRequest.Body, modelType, serializerContext, cancellationToken);
+    }
+
+    private static Task SerializeRequestAsync(HttpResponse httpResponse, object? dto, string contentType, JsonSerializerContext? serializerContext, CancellationToken cancellationToken)
+    {
+        var serializer = httpResponse.HttpContext.RequestServices.GetRequiredService<IApiSerializer>();
+        var options = serializer.GetOptions();
+
+        httpResponse.ContentType = contentType;
+        return serializerContext == null
+            ? JsonSerializer.SerializeAsync(httpResponse.Body, dto, dto?.GetType() ?? typeof(object), options, cancellationToken)
+            : JsonSerializer.SerializeAsync(httpResponse.Body, dto, dto?.GetType() ?? typeof(object), serializerContext, cancellationToken);
+    }
+
+}