NAME

       oo::object - root class of the class hierarchy

SYNOPSIS

       package require TclOO

       oo::object method ?arg ...?

CLASS HIERARCHY

       oo::object
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DESCRIPTION

       The  oo::object  class  is  the  root  class of the object hierarchy; every object is an instance of this
       class. Since classes are themselves objects, they are instances of this class  too.  Objects  are  always
       referred to by their name, and may be renamed while maintaining their identity.

       Instances  of  objects may be made with either the create or new methods of the oo::object object itself,
       or by invoking those methods on any of  the  subclass  objects;  see  oo::class  for  more  details.  The
       configuration  of  individual  objects  (i.e.,  instance-specific methods, mixed-in classes, etc.) may be
       controlled with the oo::objdefine command.

       Each object has a unique namespace associated with it, the instance namespace.  This namespace holds  all
       the  instance  variables of the object, and will be the current namespace whenever a method of the object
       is invoked (including a method of the class of the object). When the object is  destroyed,  its  instance
       namespace  is  deleted.  The  instance  namespace  contains the object's my command, which may be used to
       invoke non-exported methods of the object or to create a reference to  the  object  for  the  purpose  of
       invocation which persists across renamings of the object.

   CONSTRUCTOR
       The oo::object class does not define an explicit constructor.

   DESTRUCTOR
       The oo::object class does not define an explicit destructor.

   EXPORTED METHODS
       The oo::object class supports the following exported methods:

       obj destroy
              This  method  destroys  the  object, obj, that it is invoked upon, invoking any destructors on the
              object's class in the process. It is equivalent to using rename to delete the object command.  The
              result of this method is always the empty string.

   NON-EXPORTED METHODS
       The oo::object class supports the following non-exported methods:

       obj eval ?arg ...?
              This  method  concatenates the arguments, arg, as if with concat, and then evaluates the resulting
              script in the namespace that is  uniquely  associated  with  obj,  returning  the  result  of  the
              evaluation.

       obj unknown ?methodName? ?arg ...?
              This  method  is  called  when an attempt to invoke the method methodName on object obj fails. The
              arguments that the user supplied to the method are given  as  arg  arguments.   If  methodName  is │
              absent,  the  object was invoked with no method name at all (or any other arguments).  The default
              implementation (i.e., the one defined  by  the  oo::object  class)  generates  a  suitable  error,
              detailing what methods the object supports given whether the object was invoked by its public name
              or through the my command.

       obj variable ?varName ...?
              This method arranges for each variable called varName to be linked from the  object  obj's  unique
              namespace  into  the  caller's  context.  Thus,  if it is invoked from inside a procedure then the
              namespace variable in the object is linked to the local variable in the  procedure.  Each  varName
              argument must not have any namespace separators in it. The result is the empty string.

       obj varname varName
              This  method  returns  the globally qualified name of the variable varName in the unique namespace
              for the object obj.

       obj <cloned> sourceObjectName
              This method is used by the oo::object command to copy the state of one object to  another.  It  is │
              responsible  for  copying  the  procedures  and  variables  of  the namespace of the source object │
              (sourceObjectName) to the current object. It does not copy any other  types  of  commands  or  any │
              traces on the variables; that can be added if desired by overriding this method in a subclass.

EXAMPLES

       This example demonstrates basic use of an object.

              set obj [oo::object new]
              $obj foo             → error "unknown method foo"
              oo::objdefine $obj method foo {} {
                  my variable count
                  puts "bar[incr count]"
              }
              $obj foo             → prints "bar1"
              $obj foo             → prints "bar2"
              $obj variable count  → error "unknown method variable"
              $obj destroy
              $obj foo             → error "unknown command obj"

SEE ALSO

       my(3tcl), oo::class(3tcl)

KEYWORDS

       base class, class, object, root class