Ubuntu Manpage: Net::DBus::BaseObject - base class for exporting objects to the bus

Provided by: libnet-dbus-perl_1.1.0-3build1_amd64

NAME

       Net::DBus::BaseObject - base class for exporting objects to the bus

SYNOPSIS

         # We're going to be a DBus object
         use base qw(Net::DBus::BaseObject);

         # Export a 'Greeting' signal taking a stringl string parameter
         dbus_signal("Greeting", ["string"]);

         # Export 'Hello' as a method accepting a single string
         # parameter, and returning a single string value
         dbus_method("Hello", ["string"], ["string"]);

         sub new {
             my $class = shift;
             my $service = shift;
             my $self = $class->SUPER::new($service, "/org/demo/HelloWorld");

             bless $self, $class;

             return $self;
         }

         sub _dispatch_object {
             my $self = shift;
             my $connection = shift;
             my $message = shift;

             if (....$message refers to a object's method ... ) {
                ...dispatch this object's interfaces/methods...
                return $reply;
             }
         }

DESCRIPTION

       This the base of all objects which are exported to the message bus. It provides the core
       support for type introspection required for objects exported to the message. When sub-
       classing this object, the "_dispatch" object should be implemented to handle processing of
       incoming messages. The Net::DBus::Exporter module is used to declare which methods (and
       signals) are being exported to the message bus.

       All packages inheriting from this, will automatically have the interface
       "org.freedesktop.DBus.Introspectable" registered with Net::DBus::Exporter, and the
       "Introspect" method within this exported.

       Application developers will rarely want to use this class directly, instead either
       Net::DBus::Object or "Net::DBus::ProxyObject" are the common choices. This class will only
       be used if wanting to write a new approach to dispatching incoming method calls.

METHODS

my $object = Net::DBus::BaseObject->new($service, $path)
This creates a new DBus object with an path of $path registered within the service
$service. The $path parameter should be a string complying with the usual DBus
requirements for object paths, while the $service parameter should be an instance of
Net::DBus::Service. The latter is typically obtained by calling the "export_service"
method on the Net::DBus object.

my $object = Net::DBus::BaseObject->new($parentobj, $subpath)
This creates a new DBus child object with an path of $subpath relative to its parent
$parentobj. The $subpath parameter should be a string complying with the usual DBus
requirements for object paths, while the $parentobj parameter should be an instance of
Net::DBus::BaseObject.

$object->disconnect();
This method disconnects the object from the bus, such that it will no longer receive
messages sent by other clients. Any child objects will be recursively disconnected
too. After an object has been disconnected, it is possible for Perl to garbage collect
the object instance. It will also make it possible to connect a newly created object
to the same path.

my $bool = $object->is_connected
Returns a true value if the object is connected to the bus, and thus capable of being
accessed by remote clients. Returns false if the object is disconnected & thus ready
for garbage collection. All objects start off in the connected state, and will only
transition if the "disconnect" method is called.

my $service = $object->get_service
Retrieves the Net::DBus::Service object within which this object is exported.

my $path = $object->get_object_path
Retrieves the path under which this object is exported

$object->emit_signal_in($name, $interface, $client, @args);
Emits a signal from the object, with a name of $name. If the $interface parameter is
defined, the signal will be scoped within that interface. If the $client parameter is
defined, the signal will be unicast to that client on the bus. The signal and the data
types of the arguments @args must have been registered with Net::DBus::Exporter by
calling the "dbus_signal" method.

$self->emit_signal_to($name, $client, @args);
Emits a signal from the object, with a name of $name. The signal and the data types of
the arguments @args must have been registered with Net::DBus::Exporter by calling the
"dbus_signal" method. The signal will be sent only to the client named by the $client
parameter.

$self->emit_signal($name, @args);
Emits a signal from the object, with a name of $name. The signal and the data types of
the arguments @args must have been registered with Net::DBus::Exporter by calling the
"dbus_signal" method. The signal will be broadcast to all clients on the bus.

$object->connect_to_signal_in($name, $interface, $coderef);
Connects a callback to a signal emitted by the object. The $name parameter is the name
of the signal within the object, and $coderef is a reference to an anonymous
subroutine. When the signal $name is emitted by the remote object, the subroutine
$coderef will be invoked, and passed the parameters from the signal. The $interface
parameter is used to specify the explicit interface defining the signal to connect to.

$object->connect_to_signal($name, $coderef);
Connects a callback to a signal emitted by the object. The $name parameter is the name
of the signal within the object, and $coderef is a reference to an anonymous
subroutine. When the signal $name is emitted by the remote object, the subroutine
$coderef will be invoked, and passed the parameters from the signal.

$reply = $object->_dispatch_object($connection, $message);
The "_dispatch_object" method is to be used to handle dispatch of methods implemented
by the object. The default implementation is a no-op and should be overridden by
subclasses todo whatever processing is required. If the $message could be handled then
another "Net::DBus::Binding::Message" instance should be returned for the reply. If
"undef" is returned, then a generic error will be returned to the caller.

$currvalue = $object->_dispatch_property($name); =item $object->_dispatch_property($name,
$newvalue);
The "_dispatch_property" method is to be used to handle dispatch of property reads and
writes. The $name parameter is the name of the property being accessed. If $newvalue
is supplied then the property is to be updated, otherwise the current value is to be
returned. The default implementation will simply raise an error, so must be overridden
in subclasses.

AUTHOR

       Daniel P. Berrange

COPYRIGHT