module ActionController #:nodoc:
# Methods for sending arbitrary data and for streaming files to the browser,
# instead of rendering.
module Streaming
extend ActiveSupport::Concern
include ActionController::Rendering
DEFAULT_SEND_FILE_OPTIONS = {
:type => 'application/octet-stream'.freeze,
:disposition => 'attachment'.freeze,
}.freeze
protected
# 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, and defaults to "X-Sendfile".
# 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. <tt>send_file(params[:path])</tt> allows a malicious user to
# download any file on your server.
#
# Options:
# * <tt>:filename</tt> - suggests a filename for the browser to use.
# Defaults to <tt>File.basename(path)</tt>.
# * <tt>:type</tt> - specifies an HTTP content type. Defaults to 'application/octet-stream'. You can specify
# either a string or a symbol for a registered type register with <tt>Mime::Type.register</tt>, for example :json
# * <tt>:disposition</tt> - specifies whether the file will be shown inline or downloaded.
# Valid values are 'inline' and 'attachment' (default).
# * <tt>:status</tt> - specifies the status code to send with the response. Defaults to '200 OK'.
# * <tt>:url_based_filename</tt> - set to +true+ if you want the browser guess the filename from
# the URL, which is necessary for i18n filenames on certain browsers
# (setting <tt>:filename</tt> 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', :status => 404
#
# Read about the other Content-* HTTP headers if you'd like to
# provide the user with more information (such as Content-Description) in
# http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.11.
#
# 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
# http://www.mnot.net/cache_docs/ for an overview of web caching and
# http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.9
# for the Cache-Control header spec.
def send_file(path, options = {}) #:doc:
raise MissingFile, "Cannot read file #{path}" unless File.file?(path) and File.readable?(path)
options[:filename] ||= File.basename(path) unless options[:url_based_filename]
send_file_headers! options
if options[:x_sendfile]
ActiveSupport::Deprecation.warn(":x_sendfile is no longer needed in send_file", caller)
end
self.status = options[:status] || 200
self.content_type = options[:content_type] if options.key?(:content_type)
self.response_body = File.open(path, "rb")
end
# Sends the given binary data to the browser. This method is similar to
# <tt>render :text => data</tt>, 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 apparent file name, and other things.
#
# Options:
# * <tt>:filename</tt> - suggests a filename for the browser to use.
# * <tt>:type</tt> - specifies an HTTP content type. Defaults to 'application/octet-stream'. You can specify
# either a string or a symbol for a registered type register with <tt>Mime::Type.register</tt>, for example :json
# * <tt>:disposition</tt> - specifies whether the file will be shown inline or downloaded.
# Valid values are 'inline' and 'attachment' (default).
# * <tt>:status</tt> - specifies the status code to send with the response. Defaults to '200 OK'.
#
# 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.
#
# <b>Tip:</b> if you want to stream large amounts of on-the-fly generated
# data to the browser, then use <tt>render :text => proc { ... }</tt>
# instead. See ActionController::Base#render for more information.
def send_data(data, options = {}) #:doc:
send_file_headers! options.dup
render options.slice(:status, :content_type).merge(:text => data)
end
private
def send_file_headers!(options)
options.update(DEFAULT_SEND_FILE_OPTIONS.merge(options))
[:type, :disposition].each do |arg|
raise ArgumentError, ":#{arg} option required" if options[arg].nil?
end
if options.key?(:length)
ActiveSupport::Deprecation.warn("You do not need to provide the file's length", caller)
end
disposition = options[:disposition]
disposition += %(; filename="#{options[:filename]}") if options[:filename]
content_type = options[:type]
if content_type.is_a?(Symbol)
extension = Mime[content_type]
raise ArgumentError, "Unknown MIME type #{options[:type]}" unless extension
self.content_type = extension
else
self.content_type = content_type
end
headers.merge!(
'Content-Disposition' => disposition,
'Content-Transfer-Encoding' => 'binary'
)
response.sending_file = true
# Fix a problem with IE 6.0 on opening downloaded files:
# If Cache-Control: no-cache is set (which Rails does by default),
# IE removes the file it just downloaded from its cache immediately
# after it displays the "open/save" dialog, which means that if you
# hit "open" the file isn't there anymore when the application that
# is called for handling the download is run, so let's workaround that
response.cache_control[:public] ||= false
end
end
end
