Programming Jabber

The vcard-temp Namespace

The vcard-temp namespace represents the vCard format. It’s a format used to provide information about an entity—a person, company, or even, in Jabber’s case, a piece of software—in the form of a virtual business card.

The idea behind the vCard format, which is an emerging but as yet incomplete standard, is that it can be used to hold information about something in a formalized and parcel-like way. vCards can be attached to email messages and extracted from user directories and address books. The fact that the format is not yet a standard is reflected in the “temporary” namespace (vcard-temp) used to qualify vCard exchanges.

Note

Jabber uses the vCard format to hold details about various parts of the Jabber server; each component can have a vCard, as seen in Section 4.3 in Chapter 4. Each Jabber user can have a vCard, too.

Retrievals of vCards, and updates, are made using IQs containing extensions qualified by the vcard-temp namespace. To request a vCard, send an IQ-get to the holder of the vCard you want, like this:

SEND: <iq type='get' to='[e-mail]' id='73'>
        <vcard xmlns='vcard-temp'/>
      </iq>

Rather than the usual tag name of query, vCard <iq/> extensions have the name vcard (this is sometimes seen in all caps or as vCard).

In response to this request, the vCard belonging to qmacro will be returned as shown in Example 6-8.

Example 6-8. A response returning qmacro’s vCard

RECV: <iq id='73' to='[e-mail]/home' type='result' from='[e-mail]'> ...