send_data and send_file methods in Ruby on Rails

send_data and send_file method

send_data

Definition:

In Ruby on Rails, send_data is a method provided by the ActionController module that allows you to send binary data from your Rails application to the client’s browser.

Example:

def download_pdf
  pdf_file = generate_pdf
  send_data pdf_file, type: "application/pdf", disposition: "attachment", filename: "report.pdf"
end

In this example, the generate_pdf method sends the binary data of a PDF file, which is then passed as the first argument to send_data. The second argument is an options hash, where you can specify the content type, content layout, and file name of the data being sent. The content type and disposition are used by the client’s browser to determine how to handle the received data, while the filename is used as a default name for the file if the user saves it to disk.

send_file

Definition:

send_file is another method provided by the ActionController module in Ruby on Rails for sending binary data to the client’s browser. It’s similar to send_data but is more optimized for sending files from the file system.

Example:

def download_image
  send_file("#{Rails.root}/public/images/image.jpg", type: "image/jpeg", disposition: "inline")
end

In this example, the path to the image file is passed as the first argument to send_file. The second argument is an options hash, where you can specify the content type and content disposition of the data being sent. The content type and disposition are used by the client’s browser to determine how to handle the received data.

One of the main benefits of using send_file over send_data is that send_file can be optimized to work more efficiently with the file system, as it allows the webserver to directly serve the file without the need for Rails to read the entire file into memory first.