MySQL Cookbook, 2nd Edition

Using MySQL-Based Storage in Ruby Applications

Problem

You want to use session storage for Ruby scripts.

Solution

Use the CGI::Session class interface. By default, it uses temporary files for backing store, but you can configure it to use MySQL instead.

Discussion

The CGI::Session class manages session storage. It identifies sessions by means of cookies, which it adds transparently to the responses sent to the client. CGI::Session allows you to supply a storage-management class to be used in place of the default manager that uses temporary files. We’ll use the mysql-session package, which is based on the Ruby DBI interface and stores session records using MySQL. mysql-session is available from the Ruby Application Archive. See Appendix A for information about obtaining and installing it.

To use mysql-session in a script, you need to access these modules:

require "cgi"
require "cgi/session"
require "mysqlstore"

To create a session, first create a CGI object . Then invoke CGI::Session.new, which takes several arguments. The first is a CGI object associated with the script. (This object must exist before you can open the session.) Other arguments provide information about the session itself. Those following are relevant no matter which storage manager you use:

session_key

The session key that the session manager uses as the name of the cookie to be sent to the client. The default key value is _session_key; we will use RUBYSESSID.

new_session

This argument should be true to force a new session ...