AspNetCore SinglePageMiddleware.cs

SinglePageMiddleware.cs

using System;
using System.Threading.Tasks;
using System.Threading;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.StaticFiles;
using Microsoft.Extensions.FileProviders;
using Microsoft.Extensions.Logging;

namespace ChristopherHarris
{
    public class SinglePageMiddleware
    {
        private ILogger<SinglePageMiddleware> _logger;
        private IFileProvider _fileProvider;
        private string _filename;
        private IContentTypeProvider _contentTypeProvider;

        public SinglePageMiddleware(
            RequestDelegate next,
            IHostingEnvironment env,
            ILogger<SinglePageMiddleware> logger,
            string filename)
        {
            _logger = logger;
            _filename = filename;
            _fileProvider = env.WebRootFileProvider;
            _contentTypeProvider = new FileExtensionContentTypeProvider();
        }

        public async Task Invoke(HttpContext context)
        {
            var request = context.Request;
            var response = context.Response;
            var fileInfo = _fileProvider.GetFileInfo(_filename);

            if (!fileInfo.Exists)
            {
                _logger?.LogError($"Unable to find file: {_filename}");
                response.StatusCode = StatusCodes.Status404NotFound;
                return;
            }

            if (!request.Method.Equals(HttpMethods.Get, StringComparison.OrdinalIgnoreCase))
            {
                _logger?.LogInformation($"Request made via incompatible method: {request.Method}");
                response.StatusCode = StatusCodes.Status400BadRequest;
                return;
            }

            _logger?.LogTrace($"Delivering single static file: {_filename}");
            response.StatusCode = StatusCodes.Status200OK;
            response.ContentLength = fileInfo.Length;
            response.ContentType = GetContentType(_filename);

            await response.SendFileAsync(
                fileInfo.PhysicalPath,
                0,
                fileInfo.Length,
                CancellationToken.None);
        }

        private string GetContentType(string filename)
        {
            string contentType = null;
            _contentTypeProvider.TryGetContentType(filename, out contentType);
            return contentType;
        }
    }
}

SinglePageMiddlewareExtensions.cs

using Microsoft.AspNetCore.Builder;

namespace ChristopherHarris
{
    public static class SinglePageMiddlewareExtensions
    {
        public static void UseSinglePage(this IApplicationBuilder app, string filename)
        {
            app.UseMiddleware<SinglePageMiddleware>(filename);
        }
    }
}