aspnetcore/src/Microsoft.AspNetCore.Http.A.../Extensions/MapMiddleware.cs

76 lines
2.4 KiB
C#

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Threading.Tasks;
using Microsoft.AspNet.Http;
namespace Microsoft.AspNet.Builder.Extensions
{
/// <summary>
/// Respresents a middleware that maps a request path to a sub-request pipeline.
/// </summary>
public class MapMiddleware
{
private readonly RequestDelegate _next;
private readonly MapOptions _options;
/// <summary>
/// Creates a new instace of <see cref="MapMiddleware"/>.
/// </summary>
/// <param name="next">The delegate representing the next middleware in the request pipeline.</param>
/// <param name="options">The middleware options.</param>
public MapMiddleware(RequestDelegate next, MapOptions options)
{
if (next == null)
{
throw new ArgumentNullException(nameof(next));
}
if (options == null)
{
throw new ArgumentNullException(nameof(options));
}
_next = next;
_options = options;
}
/// <summary>
/// Executes the middleware.
/// </summary>
/// <param name="context">The <see cref="HttpContext"/> for the current request.</param>
/// <returns>A task that represents the execution of this middleware.</returns>
public async Task Invoke(HttpContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
PathString path = context.Request.Path;
PathString remainingPath;
if (path.StartsWithSegments(_options.PathMatch, out remainingPath))
{
// Update the path
PathString pathBase = context.Request.PathBase;
context.Request.PathBase = pathBase + _options.PathMatch;
context.Request.Path = remainingPath;
try
{
await _options.Branch(context);
}
finally
{
context.Request.PathBase = pathBase;
context.Request.Path = path;
}
}
else
{
await _next(context);
}
}
}
}