Programming Jabber

Preparing the RSS event function and element handlers

Jabber::Connection offers a simple way of having a function execute at regular intervals. It avoids the need for setting and resetting alarms. It is the register_beat() function:

debug("registering RSS beat");
$c->register_beat(1800, \&rss);

Calling the register_beat() method takes two arguments. The first argument represents the interval, in seconds. The second is a reference to the function that should be invoked at each interval. Here, we’re saying we want the rss() function called every 30 minutes (1800 seconds).

Most of the traffic relating to the component will be the headline messages emanating from it. However, we are expecting incoming IQ elements, particularly for registration in the jabber:iq:register namespace. We’ve also already mentioned that it’s customary for components to honor basic “administrative” queries such as version checks. So the list of calls to the register_handler() method here reflects what we want to offer in terms of handling these IQ elements:

debug("registering IQ handlers");
$c->register_handler('iq',\&iq_register);
$c->register_handler('iq',\&iq_version);
$c->register_handler('iq',\&iq_browse);
$c->register_handler('iq',\&iq_notimpl);

Whereas with Net::Jabber’s SetCallBacks() function and with Jabberpy’s setIqHandler() method we specify a single function to act as a handler for incoming <iq/> elements, we can specify as many handlers as we want for each element type with the register_handler() ...