aspnetcore/src/Microsoft.AspNet.StaticFiles/DefaultFilesMiddleware.cs

92 lines
3.9 KiB
C#

// Copyright (c) Microsoft Open Technologies, Inc. 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.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.AspNet.Builder;
using Microsoft.AspNet.FileSystems;
using Microsoft.AspNet.Http;
namespace Microsoft.AspNet.StaticFiles
{
/// <summary>
/// This examines a directory path and determines if there is a default file present.
/// If so the file name is appended to the path and execution continues.
/// Note we don't just serve the file because it may require interpretation.
/// </summary>
public class DefaultFilesMiddleware
{
private readonly DefaultFilesOptions _options;
private readonly PathString _matchUrl;
private readonly RequestDelegate _next;
/// <summary>
/// Creates a new instance of the DefaultFilesMiddleware.
/// </summary>
/// <param name="next">The next middleware in the pipeline.</param>
/// <param name="options">The configuration options for this middleware.</param>
public DefaultFilesMiddleware(RequestDelegate next, DefaultFilesOptions options)
{
if (next == null)
{
throw new ArgumentNullException("next");
}
if (options == null)
{
throw new ArgumentNullException("options");
}
if (options.FileSystem == null)
{
options.FileSystem = new PhysicalFileSystem("." + options.RequestPath.Value);
}
_next = next;
_options = options;
_matchUrl = options.RequestPath;
}
/// <summary>
/// This examines the request to see if it matches a configured directory, and if there are any files with the
/// configured default names in that directory. If so this will append the corresponding file name to the request
/// path for a later middleware to handle.
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public Task Invoke(HttpContext context)
{
IEnumerable<IFileInfo> dirContents;
PathString subpath;
if (Helpers.IsGetOrHeadMethod(context.Request.Method)
&& Helpers.TryMatchPath(context, _matchUrl, forDirectory: true, subpath: out subpath)
&& _options.FileSystem.TryGetDirectoryContents(subpath.Value, out dirContents))
{
// Check if any of our default files exist.
for (int matchIndex = 0; matchIndex < _options.DefaultFileNames.Count; matchIndex++)
{
string defaultFile = _options.DefaultFileNames[matchIndex];
IFileInfo file;
// TryMatchPath will make sure subpath always ends with a "/" by adding it if needed.
if (_options.FileSystem.TryGetFileInfo(subpath + defaultFile, out file))
{
// If the path matches a directory but does not end in a slash, redirect to add the slash.
// This prevents relative links from breaking.
if (!Helpers.PathEndsInSlash(context.Request.Path))
{
context.Response.StatusCode = 301;
context.Response.Headers[Constants.Location] = context.Request.PathBase + context.Request.Path + "/";
return Constants.CompletedTask;
}
// Match found, re-write the url. A later middleware will actually serve the file.
context.Request.Path = new PathString(context.Request.Path.Value + defaultFile);
break;
}
}
}
return _next(context);
}
}
}