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.

Methods

Class Public methods

new(root, index: "index", headers: {})

📝 Source code 
# File actionpack/lib/action_dispatch/middleware/static.rb, line 18
    def initialize(root, index: "index", headers: {})
      @root          = root.chomp("/").b
      @file_server   = ::Rack::File.new(@root, headers)
      @index         = index
    end
🔎 See on GitHub

Instance Public methods

call(env)

📝 Source code 
# File actionpack/lib/action_dispatch/middleware/static.rb, line 50
    def call(env)
      serve(Rack::Request.new(env))
    end
🔎 See on GitHub

match?(path)

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).

📝 Source code 
# 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.b)
        begin
          File.file?(path) && File.readable?(path)
        rescue SystemCallError
          false
        end

      }
        return ::Rack::Utils.escape_path(match).b
      end
    end
🔎 See on GitHub

serve(request)

📝 Source code 
# 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
🔎 See on GitHub