actionpack/lib/action_controller/metal/data_streaming.rb
# frozen_string_literal: true
# :markup: markdown
require "action_controller/metal/exceptions"
require "action_dispatch/http/content_disposition"
module ActionController # :nodoc:
# # Action Controller Data Streaming
#
# Methods for sending arbitrary data and for streaming files to the browser,
# instead of rendering.
module DataStreaming
extend ActiveSupport::Concern
include ActionController::Rendering
DEFAULT_SEND_FILE_TYPE = "application/octet-stream" # :nodoc:
DEFAULT_SEND_FILE_DISPOSITION = "attachment" # :nodoc:
private
# Sends the file. This uses a server-appropriate method (such as `X-Sendfile`)
# via the `Rack::Sendfile` middleware. The header to use is set via
# `config.action_dispatch.x_sendfile_header`. Your server can also configure
# this for you by setting the `X-Sendfile-Type` header.
#
# Be careful to sanitize the path parameter if it is coming from a web page.
# `send_file(params[:path])` allows a malicious user to download any file on
# your server.
#
# Options:
# * `:filename` - suggests a filename for the browser to use. Defaults to
# `File.basename(path)`.
# * `:type` - specifies an HTTP content type. You can specify either a string
# or a symbol for a registered type with `Mime::Type.register`, for example
# `:json`. If omitted, the type will be inferred from the file extension
# specified in `:filename`. If no content type is registered for the
# extension, the default type `application/octet-stream` will be used.
# * `:disposition` - specifies whether the file will be shown inline or
# downloaded. Valid values are `"inline"` and `"attachment"` (default).
# * `:status` - specifies the status code to send with the response. Defaults
# to 200.
# * `:url_based_filename` - set to `true` if you want the browser to guess the
# filename from the URL, which is necessary for i18n filenames on certain
# browsers (setting `:filename` overrides this option).
#
#
# The default `Content-Type` and `Content-Disposition` headers are set to
# download arbitrary binary files in as many browsers as possible. IE versions
# 4, 5, 5.5, and 6 are all known to have a variety of quirks (especially when
# downloading over SSL).
#
# Simple download:
#
# send_file '/path/to.zip'
#
# Show a JPEG in the browser:
#
# send_file '/path/to.jpeg', type: 'image/jpeg', disposition: 'inline'
#
# Show a 404 page in the browser:
#
# send_file '/path/to/404.html', type: 'text/html; charset=utf-8', disposition: 'inline', status: 404
#
# You can use other `Content-*` HTTP headers to provide additional information
# to the client. See MDN for a [list of HTTP
# headers](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers).
#
# Also be aware that the document may be cached by proxies and browsers. The
# `Pragma` and `Cache-Control` headers declare how the file may be cached by
# intermediaries. They default to require clients to validate with the server
# before releasing cached responses. See https://www.mnot.net/cache_docs/ for an
# overview of web caching and [RFC
# 9111](https://www.rfc-editor.org/rfc/rfc9111.html#name-cache-control) for the
# `Cache-Control` header spec.
def send_file(path, options = {}) # :doc:
raise MissingFile, "Cannot read file #{path}" unless File.file?(path) && File.readable?(path)
options[:filename] ||= File.basename(path) unless options[:url_based_filename]
send_file_headers! options
self.status = options[:status] || 200
self.content_type = options[:content_type] if options.key?(:content_type)
response.send_file path
end
# Sends the given binary data to the browser. This method is similar to `render
# plain: data`, but also allows you to specify whether the browser should
# display the response as a file attachment (i.e. in a download dialog) or as
# inline data. You may also set the content type, the file name, and other
# things.
#
# Options:
# * `:filename` - suggests a filename for the browser to use.
# * `:type` - specifies an HTTP content type. Defaults to
# `application/octet-stream`. You can specify either a string or a symbol
# for a registered type with `Mime::Type.register`, for example `:json`. If
# omitted, type will be inferred from the file extension specified in
# `:filename`. If no content type is registered for the extension, the
# default type `application/octet-stream` will be used.
# * `:disposition` - specifies whether the file will be shown inline or
# downloaded. Valid values are `"inline"` and `"attachment"` (default).
# * `:status` - specifies the status code to send with the response. Defaults
# to 200.
#
#
# Generic data download:
#
# send_data buffer
#
# Download a dynamically-generated tarball:
#
# send_data generate_tgz('dir'), filename: 'dir.tgz'
#
# Display an image Active Record in the browser:
#
# send_data image.data, type: image.content_type, disposition: 'inline'
#
# See `send_file` for more information on HTTP `Content-*` headers and caching.
def send_data(data, options = {}) # :doc:
send_file_headers! options
render options.slice(:status, :content_type).merge(body: data)
end
def send_file_headers!(options)
type_provided = options.has_key?(:type)
content_type = options.fetch(:type, DEFAULT_SEND_FILE_TYPE)
self.content_type = content_type
response.sending_file = true
raise ArgumentError, ":type option required" if content_type.nil?
if content_type.is_a?(Symbol)
extension = Mime[content_type]
raise ArgumentError, "Unknown MIME type #{options[:type]}" unless extension
self.content_type = extension
else
if !type_provided && options[:filename]
# If type wasn't provided, try guessing from file extension.
content_type = Mime::Type.lookup_by_extension(File.extname(options[:filename]).downcase.delete(".")) || content_type
end
self.content_type = content_type
end
disposition = options.fetch(:disposition, DEFAULT_SEND_FILE_DISPOSITION)
if disposition
headers["Content-Disposition"] = ActionDispatch::Http::ContentDisposition.format(disposition: disposition, filename: options[:filename])
end
headers["Content-Transfer-Encoding"] = "binary"
end
end
end