Invokes a node hook.
$node: A node object or a string containing the node type.
$hook: A string containing the name of the hook.
$a2, $a3, $a4: Arguments to pass on to the hook, after the $node argument.
The returned value of the invoked hook.
function node_invoke($node, $hook, $a2 = NULL, $a3 = NULL, $a4 = NULL) {
if (node_hook($node, $hook)) {
$base = node_type_get_base($node);
$function = $base . '_' . $hook;
return $function($node, $a2, $a3, $a4);
}
}