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¶
Copyright (C) 2005-2011 Daniel P. Berrange
SEE ALSO¶
Net::DBus, Net::DBus::Service, Net::DBus::Object, Net::DBus::ProxyObject,
Net::DBus::Exporter, Net::DBus::RemoteObject