NAME

       "Tangence::Object" - base class for accessible objects in a "Tangence" server

DESCRIPTION

       This class acts as a base class for the accessible objects in a Tangence server. All the
       objects actually created and made accessible to clients will be subclasses of this one,
       including internally-created objects such as Tangence::Registry.

       These objects are not directly constructed by calling the "new" class method; instead the
       "Tangence::Registry" should be used to construct one.

METHODS

   destroy
          $obj->destroy

       Requests that the object destroy itself, informing all clients that are aware of it. Once
       they all report that they have dropped the object, the object is deconstructed for real.

       Not to be confused with Perl's own "DESTROY" method.

   id
          $id = $obj->id

       Returns the object's "Tangence" ID number

   describe
          $description = $obj->describe

       Returns a textual description of the object, for internal debugging purposes.  Subclasses
       are encouraged to override this method to return something more descriptive within their
       domain of interest

   registry
          $registry = $obj->registry

       Returns the Tangence::Registry that constructed this object.

   class
          $class = $obj->class

       Returns the Tangence::Meta::Class object representing the class of this object.

   can_method
          $method = $obj->can_method( $name )

       Returns the Tangence::Meta::Method object representing the named method, or "undef" if no
       such method exists.

   can_event
          $event = $obj->can_event( $name )

       Returns the Tangence::Meta::Event object representing the named event, or "undef" if no
       such event exists.

   can_property
          $property = $obj->can_property( $name )

       Returns the Tangence::Meta::Property object representing the named property, or "undef" if
       no such property exists.

   fire_event
          $obj->fire_event( $event, @args )

       Fires the named event on the object. Each event subscription function will be invoked with
       the given arguments.

   subscribe_event
          $id = $obj->subscribe_event( $event, $callback )

       Subscribes an event-handling callback CODE ref to the named event. When the event is fired
       by "fire_event" this callback will be invoked, being passed the object reference and the
       event's arguments.

          $callback->( $obj, @args )

       Returns an opaque ID value that can be used to remove this subscription by calling
       "unsubscribe_event".

   unsubscribe_event
          $obj->unsubscribe_event( $event, $id )

       Removes an event-handling callback previously registered with "subscribe_event".

   watch_property
          $id = $obj->watch_property( $prop, %callbacks )

       Watches a named property for changes, registering a set of callback functions to be
       invoked when the property changes in certain ways. The set of callbacks required depends
       on the dimension of the property being watched.

       For all property types:

          $on_set->( $obj, $value )

       For hash properties:

          $on_add->( $obj, $key, $value )
          $on_del->( $obj, $key )

       For queue properties:

          $on_push->( $obj, @values )
          $on_shift->( $obj, $count )

       For array properties:

          $on_push->( $obj, @values )
          $on_shift->( $obj, $count )
          $on_splice->( $obj, $index, $count, @values )
          $on_move->( $obj, $index, $delta )

       For objset properties:

          $on_add->( $obj, $added_object )
          $on_del->( $obj, $deleted_object_id )

       Alternatively, a single callback may be installed that is invoked after any change of the
       property, being passed the new value entirely:

          $on_updated->( $obj, $value )

       Returns an opaque ID value that can be used to remove this watch by calling
       "unwatch_property".

   unwatch_property
          $obj->unwatch_property( $prop, $id )

       Removes the set of callback functions previously registered with "watch_property".

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>