Making an Ajax request to
index.php with the
action=ajax&rs=funcname&rsargs=arg1&rsargs=arg2&... parameters will result in a
funcname( "arg1", "arg2", ... ) call in PHP, as long as funcname is listed in
Such functions then usually return an AjaxResponse object.
$wgAjaxSearch and $wgAjaxWatch cause
wfAjaxWatch to be added to this array, respectively.