class ActionDispatch::FileHandler
This middleware returns a file's contents from disk in the body response. When initialized, it can accept optional HTTP headers, which will be set when a response containing a file's contents is delivered.
This middleware will render the file specified in env["PATH_INFO"]
where the base path is in the root
directory. For example, if the root
is set to public/
, then a request with env["PATH_INFO"]
of assets/application.js
will return a response with the contents of a file located at public/assets/application.js
if the file exists. If the file does not exist, a 404 “File not Found” response will be returned.
Public Class Methods
# File actionpack/lib/action_dispatch/middleware/static.rb, line 18 def initialize(root, index: "index", headers: {}) @root = root.chomp("/") @file_server = ::Rack::File.new(@root, headers) @index = index end
Public Instance Methods
# File actionpack/lib/action_dispatch/middleware/static.rb, line 50 def call(env) serve(Rack::Request.new(env)) end
Takes a path to a file. If the file is found, has valid encoding, and has correct read permissions, the return value is a URI-escaped string representing the filename. Otherwise, false is returned.
Used by the Static
class to check the existence of a valid file in the server's public/
directory (see Static#call
).
# File actionpack/lib/action_dispatch/middleware/static.rb, line 30 def match?(path) path = ::Rack::Utils.unescape_path path return false unless ::Rack::Utils.valid_path? path path = ::Rack::Utils.clean_path_info path paths = [path, "#{path}#{ext}", "#{path}/#{@index}#{ext}"] if match = paths.detect { |p| path = File.join(@root, p.dup.force_encoding(Encoding::UTF_8)) begin File.file?(path) && File.readable?(path) rescue SystemCallError false end } return ::Rack::Utils.escape_path(match) end end
# File actionpack/lib/action_dispatch/middleware/static.rb, line 54 def serve(request) path = request.path_info gzip_path = gzip_file_path(path) if gzip_path && gzip_encoding_accepted?(request) request.path_info = gzip_path status, headers, body = @file_server.call(request.env) if status == 304 return [status, headers, body] end headers["Content-Encoding"] = "gzip" headers["Content-Type"] = content_type(path) else status, headers, body = @file_server.call(request.env) end headers["Vary"] = "Accept-Encoding" if gzip_path return [status, headers, body] ensure request.path_info = path end
Private Instance Methods
# File actionpack/lib/action_dispatch/middleware/static.rb, line 82 def content_type(path) ::Rack::Mime.mime_type(::File.extname(path), "text/plain".freeze) end
# File actionpack/lib/action_dispatch/middleware/static.rb, line 78 def ext ::ActionController::Base.default_static_extension end
# File actionpack/lib/action_dispatch/middleware/static.rb, line 86 def gzip_encoding_accepted?(request) request.accept_encoding.any? { |enc, quality| enc =~ /\bgzip\b/i } end
# File actionpack/lib/action_dispatch/middleware/static.rb, line 90 def gzip_file_path(path) can_gzip_mime = content_type(path) =~ /\A(?:text\/|application\/javascript)/ gzip_path = "#{path}.gz" if can_gzip_mime && File.exist?(File.join(@root, ::Rack::Utils.unescape_path(gzip_path))) gzip_path else false end end