send_stream

Sends a stream to the browser, which is helpful when you’re generating exports or other running data where you don’t want the entire file buffered in memory first. Similar to send_data, but where the data is generated live.

Options:

• :filename - suggests a filename for the browser to use.

• :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, 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).

Example of generating a csv export:

send_stream(filename: "subscribers.csv") do |stream|
  stream.write "email_address,updated_at\n"

  @subscribers.find_each do |subscriber|
    stream.write "#{subscriber.email_address},#{subscriber.updated_at}\n"
  end
end