In Chapter 8, Adding authentication we used so-called memory users, with a list of users in an XML file. When you need a more dynamic list of users, you can use RIFE's support for database users. We'll describe how this differs from memory users somewhat briefly here.

First, we need to make the authentication element extend rife/authenticated/database.xml instead of memory.xml. We also need to specify the configuration file for the data source to use. Let's take a look at an example element file:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE element SYSTEM "/dtd/element.dtd">
      
<element extends="rife/authenticated/database.xml">

  <property name="template_name">auth</property>
  <property name="role">admin</property>
  <property name="datasource"><datasource>postgresql</datasource></property>

  <submission name="credentials">
    <param name="login"/>
    <param name="password"/>
  </submission>

  <childtrigger name="authid"/>

</element>

Then you need to create DatabaseUsers and DatabaseSessions objects using DatabaseUsersFactory and DatabaseSessionsFactory. RIFE comes with support for database users for Oracle, PostgreSQL and MySQL so you don't need to write any code if you use those. Then you call the install methods of the users and sessions objects, after which authentication works just like for memory users.

The installation of the user and session tables has to be performed before we use them. It can be done, for example, in a separate "setup" subsite where the admin is authenticated as a memory user.

Datasource source = Datasources.getRepInstance().
  getDatasource(Config.getRepInstance().getString("DATASOURCE"));

DatabaseUsersFactory.getInstance(source).install(); 
DatabaseSessionFactory.getInstance(source).install();

<element extends="rife/authenticated/purgingdatabase.xml">