Programming Jabber

Chapter 6. Jabber Namespaces

While the building blocks of the Jabber protocol, described in Chapter 5, provide the groundwork for our solutions, for our chess rules, something is still missing.

A purity and elegance can be had with use of the three core elements, <message/>, <presence/>, and <iq/>, but a depth of meaning is missing. While the core elements define the moves we can make, it’s the Jabber namespaces that provide us with the contextual set-moves that allow us to relate Jabber to the real world.

Namespaces provide a level of meaning, an environmental layer, above the basic “packet-shunting” world that would exist if our elements were to be passed back and forth bereft of context and application.

Basic activities such as user registration, authentication, roster management, and time-stamping are made possible by the application of standard Jabber namespaces to our elements. This chapter serves as a reference for all of Jabber’s IQ and X namespaces. The IQ namespaces are used to qualify attachments to <iq/> elements, while the X namespaces are more ad hoc, and are used to add value, context, and information to any type of packet.