module ActionController::DataStreaming
Action Controller Data Streaming
Methods for sending arbitrary data and for streaming files to the browser, instead of rendering.
Inherits From
-
module
ActionController::
Rendering
Private instance methods
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.
Source code GitHub
# File actionpack/lib/action_controller/metal/data_streaming.rb, line 120
def send_data(data, options = {}) # :doc:
send_file_headers! options
render options.slice(:status, :content_type).merge(body: data)
end
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.
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 www.mnot.net/cache_docs/ for an overview of web caching and RFC 9111 for the Cache-Control
header spec.
Source code GitHub
# File actionpack/lib/action_controller/metal/data_streaming.rb, line 76
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