Part 7

Part 7

Author: fullstackhub-io

UserManagement.API/ClientApp/src/app/user-management-api.ts

@@ -0,0 +1,68 @@
+namespace UserManagement.API.Common
+{
+    using Microsoft.AspNetCore.Builder;
+    using Microsoft.AspNetCore.Http;
+    using Newtonsoft.Json;
+    using System;
+    using System.Net;
+    using System.Threading.Tasks;
+    using UserManagement.Application.Common.Exceptions;
+
+    public class CustomExceptionHandlerMiddleware
+    {
+        private readonly RequestDelegate _next;
+
+        public CustomExceptionHandlerMiddleware(RequestDelegate next)
+        {
+            _next = next;
+        }
+
+        public async Task Invoke(HttpContext context)
+        {
+            try
+            {
+                await _next(context);
+            }
+            catch (Exception ex)
+            {
+                await HandleExceptionAsync(context, ex);
+            }
+        }
+
+        private Task HandleExceptionAsync(HttpContext context, Exception exception)
+        {
+            var code = HttpStatusCode.InternalServerError;
+
+            var result = string.Empty;
+
+            switch (exception)
+            {
+                case ValidationException validationException:
+                    code = HttpStatusCode.BadRequest;
+                    result = JsonConvert.SerializeObject(validationException.Errors);
+                    break;
+                case NotFoundException _:
+                    code = HttpStatusCode.NotFound;
+                    break;
+            }
+
+            context.Response.ContentType = "application/json";
+            context.Response.StatusCode = (int)code;
+
+            if (string.IsNullOrEmpty(result))
+            {
+                result = JsonConvert.SerializeObject(new { error = exception.Message });
+            }
+
+            return context.Response.WriteAsync(result);
+        }
+    }
+
+    public static class CustomExceptionHandlerMiddlewareExtensions
+    {
+        public static IApplicationBuilder UseCustomExceptionHandler(this IApplicationBuilder builder)
+        {
+            return builder.UseMiddleware<CustomExceptionHandlerMiddleware>();
+        }
+    }
+}

UserManagement.API/Common/CustomExceptionHandlerMiddleware.cs

@@ -0,0 +1,18 @@
+namespace UserManagement.API.Controllers
+{
+    using MediatR;
+    using Microsoft.AspNetCore.Mvc;
+    using Microsoft.Extensions.DependencyInjection;
+
+    [Route("api/[controller]")]
+    [ApiController]
+    public class BaseController : ControllerBase
+    {
+        private IMediator mediator;
+
+        /// <summary>
+        /// Gets the Mediator.
+        /// </summary>
+        protected IMediator Mediator => this.mediator ??= this.HttpContext.RequestServices.GetService<IMediator>();
+    }
+}

UserManagement.API/Controllers/BaseController.cs

@@ -0,0 +1,43 @@
+namespace UserManagement.API.Controllers
+{
+    using System.Threading.Tasks;
+    using Microsoft.AspNetCore.Mvc;
+    using UserManagement.Application.User.Commands;
+    using UserManagement.Application.User.Queries;
+    using UserManagement.Application.User.VM;
+
+    [Route("api/[controller]")]
+    [ApiController]
+    public class UserController : BaseController
+    {
+        [HttpGet("[action]")]
+        public async Task<ActionResult<UserVM>> Get(int userID)
+        {
+            return await this.Mediator.Send(new GetSingleUserQuery { UserID = userID });
+        }
+
+        [HttpGet("[action]")]
+        public async Task<ActionResult<UserVM>> GetAll()
+        {
+            return await this.Mediator.Send(new GetAllUserQuery());
+        }
+
+        [HttpPost("[action]")]
+        public async Task<ActionResult<int>> Post(AddUserCommand command)
+        {
+            return await this.Mediator.Send(command);
+        }
+
+        [HttpPut("[action]")]
+        public async Task<ActionResult<bool>> Put(UpdateUserCommand command)
+        {
+            return await this.Mediator.Send(command);
+        }
+
+        [HttpDelete("[action]")]
+        public async Task<ActionResult<bool>> Delete(int userID)
+        {
+            return await this.Mediator.Send(new DeleteUserCommand { UserID = userID });
+        }
+    }
+}

UserManagement.API/Controllers/UserController.cs

@@ -0,0 +1,108 @@
+namespace UserManagement.API.Filters
+{
+    using UserManagement.Application.Common.Exceptions;
+    using Microsoft.AspNetCore.Http;
+    using Microsoft.AspNetCore.Mvc;
+    using Microsoft.AspNetCore.Mvc.Filters;
+    using System;
+    using System.Collections.Generic;
+    public class ApiExceptionFilterAttribute : ExceptionFilterAttribute
+    {
+
+        private readonly IDictionary<Type, Action<ExceptionContext>> _exceptionHandlers;
+
+        public ApiExceptionFilterAttribute()
+        {
+            // Register known exception types and handlers.
+            _exceptionHandlers = new Dictionary<Type, Action<ExceptionContext>>
+            {
+                { typeof(ValidationException), HandleValidationException },
+                { typeof(NotFoundException), HandleNotFoundException },
+            };
+        }
+
+        public override void OnException(ExceptionContext context)
+        {
+            HandleException(context);
+
+            base.OnException(context);
+        }
+
+        private void HandleException(ExceptionContext context)
+        {
+            Type type = context.Exception.GetType();
+            if (_exceptionHandlers.ContainsKey(type))
+            {
+                _exceptionHandlers[type].Invoke(context);
+                return;
+            }
+
+            if (!context.ModelState.IsValid)
+            {
+                HandleInvalidModelStateException(context);
+                return;
+            }
+
+            HandleUnknownException(context);
+        }
+
+        private void HandleUnknownException(ExceptionContext context)
+        {
+            var details = new ProblemDetails
+            {
+                Status = StatusCodes.Status500InternalServerError,
+                Title = "An error occurred while processing your request.",
+                Type = "https://tools.ietf.org/html/rfc7231#section-6.6.1"
+            };
+
+            context.Result = new ObjectResult(details)
+            {
+                StatusCode = StatusCodes.Status500InternalServerError
+            };
+
+            context.ExceptionHandled = true;
+        }
+
+        private void HandleValidationException(ExceptionContext context)
+        {
+            var exception = context.Exception as ValidationException;
+
+            var details = new ValidationProblemDetails(exception.Errors)
+            {
+                Type = "https://tools.ietf.org/html/rfc7231#section-6.5.1"
+            };
+
+            context.Result = new BadRequestObjectResult(details);
+
+            context.ExceptionHandled = true;
+        }
+
+        private void HandleInvalidModelStateException(ExceptionContext context)
+        {
+            var details = new ValidationProblemDetails(context.ModelState)
+            {
+                Type = "https://tools.ietf.org/html/rfc7231#section-6.5.1"
+            };
+
+            context.Result = new BadRequestObjectResult(details);
+
+            context.ExceptionHandled = true;
+        }
+
+        private void HandleNotFoundException(ExceptionContext context)
+        {
+            var exception = context.Exception as NotFoundException;
+
+            var details = new ProblemDetails()
+            {
+                Type = "https://tools.ietf.org/html/rfc7231#section-6.5.4",
+                Title = "The specified resource was not found.",
+                Detail = exception.Message
+            };
+
+            context.Result = new NotFoundObjectResult(details);
+
+            context.ExceptionHandled = true;
+        }
+    }
+}

UserManagement.API/Controllers/WeatherForecastController.cs

@@ -1,13 +1,16 @@
-using Microsoft.AspNetCore.Builder;
-using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.HttpsPolicy;
-using Microsoft.AspNetCore.SpaServices.AngularCli;
-using Microsoft.Extensions.Configuration;
-using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Hosting;
-
 namespace UserManagement.API
 {
+    using FluentValidation.AspNetCore;
+    using Microsoft.AspNetCore.Builder;
+    using Microsoft.AspNetCore.Hosting;
+    using Microsoft.AspNetCore.Mvc;
+    using Microsoft.AspNetCore.SpaServices.AngularCli;
+    using Microsoft.Extensions.Configuration;
+    using Microsoft.Extensions.DependencyInjection;
+    using Microsoft.Extensions.Hosting;
+    using UserManagement.API.Filters;
+    using UserManagement.Application;
+    using UserManagement.Persistence;
     public class Startup
     {
         public Startup(IConfiguration configuration)
@@ -20,12 +23,35 @@ public Startup(IConfiguration configuration)
         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
-            services.AddControllersWithViews();
+            services.AddApplication();
+            services.AddPersistance();
+
+            services.AddHttpContextAccessor();
+
+            services.AddControllersWithViews(options =>
+                options.Filters.Add(new ApiExceptionFilterAttribute()))
+                    .AddFluentValidation();
+
+            services.AddRazorPages();
+
+            // Customise default API behaviour
+            services.Configure<ApiBehaviorOptions>(options =>
+            {
+                options.SuppressModelStateInvalidFilter = true;
+            });
+
             // In production, the Angular files will be served from this directory
             services.AddSpaStaticFiles(configuration =>
             {
                 configuration.RootPath = "ClientApp/dist";
             });
+
+            services.AddOpenApiDocument(configure =>
+            {
+                configure.Title = "UserManagement API";
+            });
+
+            services.AddLogging();
         }
 
         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
@@ -49,13 +75,20 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
                 app.UseSpaStaticFiles();
             }
 
+            app.UseSwaggerUi3(settings =>
+            {
+                settings.Path = "/api";
+                settings.DocumentPath = "/api/specification.json";
+            });
+
             app.UseRouting();
 
             app.UseEndpoints(endpoints =>
             {
                 endpoints.MapControllerRoute(
                     name: "default",
                     pattern: "{controller}/{action=Index}/{id?}");
+                endpoints.MapRazorPages();
             });
 
             app.UseSpa(spa =>
@@ -72,4 +105,4 @@ public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
             });
         }
     }
-}
+}