SweetMeSoft.Middleware 1.10.108

SweetMeSoft.Middleware

Library with a set of Middlewares and services for ASP.NET Core applications.

Description

SweetMeSoft.Middleware is a library for .NET Standard 2.1 that offers components for ASP.NET Core, designed to centralize error management, log requests and facilitate access to services through a Factory pattern.

Main Components

1. ErrorHandlerMiddleware

A middleware for global exception management. Captures unhandled exceptions in the application and transforms them into a standardized JSON response with ProblemDetails format.

Behavior:

• AppException (custom exception): Returns 400 Bad Request.
• KeyNotFoundException: Returns 404 Not Found.
• Any other exception: Returns 500 Internal Server Error.

2. RequestLoggingMiddleware

A middleware to log request and response details. It is highly configurable, as it allows injecting a custom logging function.

Behavior:

• Intercepts the request and response to read their bodies.
• Invokes a writeLog function that you pass in the constructor, providing it with the HttpContext, response body, status code and request body.
• Also includes its own exception handling, which logs and formats as ProblemDetails.

3. ServiceFactory

An implementation of the Factory pattern (IServiceFactory) that integrates with the ASP.NET Core dependency injection container. It allows decoupling business logic from direct implementation of IServiceProvider.

Dependencies

• Microsoft.AspNetCore.Http.Abstractions
• Microsoft.AspNetCore.Mvc.Core
• Newtonsoft.Json
• SweetMeSoft.Tools

Installation

dotnet add package SweetMeSoft.Middleware

Usage

Configuration in Startup.cs

You must register the components in your Startup.cs class (or Program.cs in .NET 6+).

using SweetMeSoft.Middleware;
using SweetMeSoft.Middleware.Interface;
using SweetMeSoft.Middleware.Service;

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        // ... other services
        
        // 1. Register the ServiceFactory
        services.AddScoped<IServiceFactory, ServiceFactory>();
        
        // ... register your own services (e.g. IMyService, MyService)
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        // ...
        
        // 2. Add middlewares to the pipeline
        // Order is important. ErrorHandler usually goes first.
        app.UseMiddleware<ErrorHandlerMiddleware>();

        // For RequestLoggingMiddleware, you must provide your own logging logic
        app.UseMiddleware<RequestLoggingMiddleware>(async (httpContext, responseBody, statusCode, requestBody) => 
        {
            // Your logging logic here
            // Example:
            Console.WriteLine($"Request: {requestBody} | Status: {statusCode} | Response: {responseBody}");
            await Task.CompletedTask;
        });

        app.UseRouting();
        // ...
    }
}

Using IServiceFactory in a Controller

Inject IServiceFactory into your controllers or services to get instances of other services.

using SweetMeSoft.Middleware.Interface;
using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("[controller]")]
public class MyController : ControllerBase
{
    private readonly IMyService myService;

    // Inject the factory in the constructor
    public MyController(IServiceFactory factory)
    {
        // Use the factory to get the service you need
        this.myService = factory.Get<IMyService>();
    }

    [HttpGet]
    public IActionResult Get()
    {
        var data = myService.GetData();
        return Ok(data);
    }
}

Throw Custom Exceptions

From your business logic, you can throw an AppException to generate a controlled 400 Bad Request response.

public class MyService : IMyService
{
    public string GetData()
    {
        // ...
        if (string.IsNullOrEmpty(someValue))
        {
            // This will be caught by ErrorHandlerMiddleware
            throw new AppException("The value cannot be null.");
        }
        // ...
    }
}

License

This project is under the MIT license.