Nextended.Web

ASP.NET Core and web application helpers, extensions, and utilities.

Overview

Nextended.Web provides utilities for ASP.NET Core applications, including controller extensions, HTTP helpers, and OData support.

Installation

dotnet add package Nextended.Web

Key Features

1. Controller Extensions

Enhanced controller functionality for ASP.NET Core MVC and API controllers.

using Nextended.Web.Extensions;
using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("api/[controller]")]
public class UsersController : ControllerBase
{
    [HttpGet]
    public IActionResult GetUsers()
    {
        // Use extension methods
        var users = GetUserData();
        return Ok(users);
    }
}

2. HTTP Helpers

Utilities for working with HTTP requests and responses.

using Nextended.Web.Helper;

public class ApiService
{
    public async Task<T> GetDataAsync<T>(string url)
    {
        return await HttpHelper.GetAsync<T>(url);
    }
    
    public async Task<bool> PostDataAsync<T>(string url, T data)
    {
        var response = await HttpHelper.PostAsync(url, data);
        return response.IsSuccessStatusCode;
    }
}

3. OData Support

Extensions for working with OData in ASP.NET Core.

using Nextended.Web.OData;
using Microsoft.AspNetCore.OData;

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllers()
            .AddOData(options => options
                .EnableQueryFeatures()
                .AddRouteComponents("odata", GetEdmModel())
            );
    }
}

Usage Examples

RESTful API Controller

using Microsoft.AspNetCore.Mvc;
using Nextended.Web.Extensions;
using Nextended.Core.Extensions;

[ApiController]
[Route("api/[controller]")]
public class ProductsController : ControllerBase
{
    private readonly IProductService _productService;
    
    public ProductsController(IProductService productService)
    {
        _productService = productService;
    }
    
    [HttpGet]
    public async Task<IActionResult> GetAll([FromQuery] string search = null)
    {
        var products = await _productService.GetProductsAsync(search);
        return Ok(products);
    }
    
    [HttpGet("{id}")]
    public async Task<IActionResult> GetById(int id)
    {
        var product = await _productService.GetProductByIdAsync(id);
        
        if (product == null)
            return NotFound();
        
        return Ok(product);
    }
    
    [HttpPost]
    public async Task<IActionResult> Create([FromBody] ProductCreateDto dto)
    {
        if (!ModelState.IsValid)
            return BadRequest(ModelState);
        
        var product = dto.MapTo<Product>();
        await _productService.CreateProductAsync(product);
        
        return CreatedAtAction(nameof(GetById), new { id = product.Id }, product);
    }
    
    [HttpPut("{id}")]
    public async Task<IActionResult> Update(int id, [FromBody] ProductUpdateDto dto)
    {
        var existing = await _productService.GetProductByIdAsync(id);
        if (existing == null)
            return NotFound();
        
        dto.MapTo(existing);
        await _productService.UpdateProductAsync(existing);
        
        return NoContent();
    }
    
    [HttpDelete("{id}")]
    public async Task<IActionResult> Delete(int id)
    {
        var result = await _productService.DeleteProductAsync(id);
        
        if (!result)
            return NotFound();
        
        return NoContent();
    }
}

OData Controller

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.OData.Query;
using Microsoft.AspNetCore.OData.Routing.Controllers;

public class OrdersController : ODataController
{
    private readonly ApplicationDbContext _context;
    
    public OrdersController(ApplicationDbContext context)
    {
        _context = context;
    }
    
    [EnableQuery]
    public IActionResult Get()
    {
        return Ok(_context.Orders);
    }
    
    [EnableQuery]
    public IActionResult Get(int key)
    {
        var order = _context.Orders.FirstOrDefault(o => o.Id == key);
        
        if (order == null)
            return NotFound();
        
        return Ok(order);
    }
}

Middleware Example

using Microsoft.AspNetCore.Http;
using Nextended.Core.Extensions;

public class RequestLoggingMiddleware
{
    private readonly RequestDelegate _next;
    private readonly ILogger<RequestLoggingMiddleware> _logger;
    
    public RequestLoggingMiddleware(
        RequestDelegate next, 
        ILogger<RequestLoggingMiddleware> logger)
    {
        _next = next;
        _logger = logger;
    }
    
    public async Task InvokeAsync(HttpContext context)
    {
        var startTime = DateTime.UtcNow;
        
        try
        {
            await _next(context);
        }
        finally
        {
            var duration = DateTime.UtcNow - startTime;
            _logger.LogInformation(
                "Request {Method} {Path} completed in {Duration}ms with status {StatusCode}",
                context.Request.Method,
                context.Request.Path,
                duration.TotalMilliseconds,
                context.Response.StatusCode
            );
        }
    }
}

// Extension method for middleware registration
public static class MiddlewareExtensions
{
    public static IApplicationBuilder UseRequestLogging(
        this IApplicationBuilder builder)
    {
        return builder.UseMiddleware<RequestLoggingMiddleware>();
    }
}

API Error Handling

using Microsoft.AspNetCore.Diagnostics;
using Microsoft.AspNetCore.Http;
using System.Net;

public class ErrorHandlingMiddleware
{
    private readonly RequestDelegate _next;
    
    public ErrorHandlingMiddleware(RequestDelegate next)
    {
        _next = next;
    }
    
    public async Task InvokeAsync(HttpContext context)
    {
        try
        {
            await _next(context);
        }
        catch (Exception ex)
        {
            await HandleExceptionAsync(context, ex);
        }
    }
    
    private static Task HandleExceptionAsync(HttpContext context, Exception exception)
    {
        var code = HttpStatusCode.InternalServerError;
        var result = string.Empty;
        
        switch (exception)
        {
            case ArgumentException _:
            case ValidationException _:
                code = HttpStatusCode.BadRequest;
                result = exception.Message;
                break;
            case NotFoundException _:
                code = HttpStatusCode.NotFound;
                result = exception.Message;
                break;
            case UnauthorizedException _:
                code = HttpStatusCode.Unauthorized;
                result = "Unauthorized";
                break;
            default:
                result = "An error occurred processing your request.";
                break;
        }
        
        context.Response.ContentType = "application/json";
        context.Response.StatusCode = (int)code;
        
        return context.Response.WriteAsJsonAsync(new
        {
            error = result,
            statusCode = (int)code
        });
    }
}

File Upload Handling

[ApiController]
[Route("api/[controller]")]
public class FilesController : ControllerBase
{
    private readonly IFileService _fileService;
    
    public FilesController(IFileService fileService)
    {
        _fileService = fileService;
    }
    
    [HttpPost("upload")]
    [RequestSizeLimit(10_000_000)] // 10 MB limit
    public async Task<IFormFile> Upload(IFormFile file)
    {
        if (file == null || file.Length == 0)
            return BadRequest("No file uploaded");
        
        // Validate file type
        var allowedExtensions = new[] { ".jpg", ".jpeg", ".png", ".pdf" };
        var extension = Path.GetExtension(file.FileName).ToLowerInvariant();
        
        if (!allowedExtensions.Contains(extension))
            return BadRequest("Invalid file type");
        
        // Process file
        using var stream = file.OpenReadStream();
        var fileId = await _fileService.SaveFileAsync(stream, file.FileName);
        
        return Ok(new { fileId, fileName = file.FileName });
    }
    
    [HttpGet("download/{fileId}")]
    public async Task<IActionResult> Download(string fileId)
    {
        var fileData = await _fileService.GetFileAsync(fileId);
        
        if (fileData == null)
            return NotFound();
        
        return File(
            fileData.Content, 
            fileData.ContentType, 
            fileData.FileName
        );
    }
}

File Download with ControllerExtensions

Nextended.Web provides DownloadDataAsync extension methods for efficient file downloads with proper headers:

using Nextended.Web.Extensions;

[ApiController]
[Route("api/[controller]")]
public class ReportsController : ControllerBase
{
    [HttpGet("export/{reportId}")]
    public async Task ExportReport(string reportId)
    {
        // Generate report data
        var reportData = await GenerateReportAsync(reportId);
        using var stream = new MemoryStream(reportData);
        
        // Download with proper headers
        await this.DownloadDataAsync(
            dataContent: stream,
            mimeType: "application/pdf",
            fileName: $"report-{reportId}.pdf",
            inlineFile: false, // Force download dialog
            httpStatusCode: 200
        );
    }
    
    [HttpGet("preview/{documentId}")]
    public async Task PreviewDocument(string documentId)
    {
        var documentData = await GetDocumentAsync(documentId);
        using var stream = new MemoryStream(documentData);
        
        // Display inline in browser
        await this.DownloadDataAsync(
            dataContent: stream,
            mimeType: "application/pdf",
            fileName: $"document-{documentId}.pdf",
            inlineFile: true, // Display in browser
            httpStatusCode: 200
        );
    }
    
    [HttpGet("csv-export")]
    public async Task ExportToCsv()
    {
        // Stream large CSV data efficiently
        await this.DownloadDataAsync(
            writeResponseDataAction: async (outputStream) =>
            {
                using var writer = new StreamWriter(outputStream);
                await writer.WriteLineAsync("Id,Name,Email,Created");
                
                // Stream data in chunks
                await foreach (var user in GetUsersAsync())
                {
                    await writer.WriteLineAsync(
                        $"{user.Id},{user.Name},{user.Email},{user.Created:yyyy-MM-dd}");
                }
            },
            mimeType: "text/csv",
            fileName: "users-export.csv",
            inlineFile: false,
            httpStatusCode: 200
        );
    }
}

Best Practices

1. Use DTOs for API Requests/Responses

public class UserDto
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Email { get; set; }
}

public class CreateUserDto
{
    [Required]
    [MaxLength(100)]
    public string Name { get; set; }
    
    [Required]
    [EmailAddress]
    public string Email { get; set; }
}

2. Implement Proper Validation

[HttpPost]
public async Task<IActionResult> Create([FromBody] CreateUserDto dto)
{
    if (!ModelState.IsValid)
    {
        return BadRequest(new ValidationProblemDetails(ModelState));
    }
    
    // Process request
    var user = await _userService.CreateUserAsync(dto);
    return CreatedAtAction(nameof(GetById), new { id = user.Id }, user);
}

3. Use Async/Await Consistently

[HttpGet]
public async Task<IActionResult> GetUsers()
{
    var users = await _userService.GetAllUsersAsync();
    return Ok(users);
}

4. Implement Proper Status Codes

// 200 OK - Success
return Ok(data);

// 201 Created - Resource created
return CreatedAtAction(nameof(GetById), new { id }, resource);

// 204 No Content - Success with no body
return NoContent();

// 400 Bad Request - Client error
return BadRequest("Invalid input");

// 404 Not Found - Resource not found
return NotFound();

// 500 Internal Server Error - Server error
return StatusCode(500, "Internal server error");

Configuration

Program.cs Setup

using Nextended.Web.Extensions;

var builder = WebApplication.CreateBuilder(args);

// Add services
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

// Add Nextended.Web services
// builder.Services.AddNextendedWeb();

var app = builder.Build();

// Configure middleware
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();
app.UseAuthorization();
app.MapControllers();

app.Run();

Supported Frameworks

• .NET 8.0
• .NET 9.0

Dependencies

• Nextended.Core - Core utilities and extensions
• Nextended.EF - Entity Framework extensions
• Microsoft.AspNetCore.OData - OData support

Related Projects

• Nextended.Core - Foundation library
• Nextended.EF - Database operations
• Nextended.Blazor - Blazor components

Links

• NuGet Package
• Source Code
• Report Issues