class ActionDispatch::FileHandler - actionpack-4.2.3 Documentation

# class ActionDispatch::FileHandler

This middleware returns a file's contents from disk in the body response. When initialized it can accept an optional 'Cache-Control' header which will be set when a response containing a file's contents is delivered.

This middleware will render the file specified in `env` where the base path is in the `root` directory. For example if the `root` is set to `public/` then a request with `env` of `assets/application.js` will return a response with 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

new(root, cache_control) click to toggle source

    # File lib/action_dispatch/middleware/static.rb, line 16
    def initialize(root, cache_control)
      @root          = root.chomp('/')
      @compiled_root = /^#{Regexp.escape(root)}/
      headers        = cache_control && { 'Cache-Control' => cache_control }
      @file_server = ::Rack::File.new(@root, headers)
    end

### Public Instance Methods

call(env) click to toggle source

    # File lib/action_dispatch/middleware/static.rb, line 44
    def call(env)
      path      = env['PATH_INFO']
      gzip_path = gzip_file_path(path)

      if gzip_path && gzip_encoding_accepted?(env)
        env['PATH_INFO']            = gzip_path
        status, headers, body       = @file_server.call(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(env)
      end

      headers['Vary'] = 'Accept-Encoding' if gzip_path

      return [status, headers, body]
    ensure
      env['PATH_INFO'] = path
    end

match?(path) click to toggle source

    # File lib/action_dispatch/middleware/static.rb, line 23
    def match?(path)
      path = URI.parser.unescape(path)
      return false unless path.valid_encoding?

      paths = [path, "#{path}#{ext}", "#{path}/index#{ext}"].map { |v|
        Rack::Utils.clean_path_info v
      }

      if match = paths.detect { |p|
        path = File.join(@root, p.force_encoding('UTF-8'))
        begin
          File.file?(path) && File.readable?(path)
        rescue SystemCallError
          false
        end

      }
        return ::Rack::Utils.escape(match)
      end
    end

### Private Instance Methods

content_type(path) click to toggle source

    # File lib/action_dispatch/middleware/static.rb, line 72
    def content_type(path)
      ::Rack::Mime.mime_type(::File.extname(path), 'text/plain')
    end

ext() click to toggle source

    # File lib/action_dispatch/middleware/static.rb, line 68
    def ext
      ::ActionController::Base.default_static_extension
    end

gzip_encoding_accepted?(env) click to toggle source

    # File lib/action_dispatch/middleware/static.rb, line 76
    def gzip_encoding_accepted?(env)
      env['HTTP_ACCEPT_ENCODING'] =~ /\bgzip\b/i
    end

gzip_file_path(path) click to toggle source

    # File lib/action_dispatch/middleware/static.rb, line 80
    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(gzip_path)))
        gzip_path
      else
        false
      end
    end