Programming Jabber

Component Connection Methods

The notion of components providing distinct services and being coordinated by a central mechanism (jabberd) suggests a certain amount of independence and individuality—a plug-in architecture—and that is what Jabber is. The components described earlier, and others too, are “plugged in” to the Jabber backbone according to the requirements of the server.

The idea is that once you have the basic services like Session Management, Client (to Server) Connectivity, and Data Storage, you plug in whatever you need to suit the server’s requirements. For example if you need conferencing facilities, you can plug in the Conferencing component. If you need user directory facilities, you can plug in the Jabber User Directory (JUD) component. If you need a bridge to the Yahoo! Instant Messaging system, you can plug in the Yahoo! Transport component. You can also connect to a component running on another Jabber server, as you’ll see later in this chapter. You can write your own components and plug those in as well to provide services not available off the shelf. We build our own components in Section 9.3 in Chapter 9 and Section 10.3 in Chapter 10.

Components are plugged in to the Jabber server backbone in one of three ways:^[1]

• Library load

• TCP sockets

• STDIO

Let’s examine each one in turn.

^[1] The log component(s) are actually part of the backbone, and as such do not need to be plugged in.