bionic (3) oo_copy.3tcl.gz

NAME

       oo::copy - create copies of objects and classes

SYNOPSIS

       package require TclOO

       oo::copy sourceObject ?targetObject? ?targetNamespace?
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DESCRIPTION

       The oo::copy command creates a copy of an object or class. It takes the name of the object or class to be
       copied, sourceObject, and optionally the name of the object or class to create, targetObject, which  will
       be resolved relative to the current namespace if not an absolute qualified name and targetNamespace which │
       is the name of the namespace that will hold the internal state of the object (my command, etc.); it  must │
       not  refer to an existing namespace.  If either targetObject or targetNamespace is omitted or is given as │
       the empty string, a new name is chosen. Names, unless specified, are chosen with the same algorithm  used │
       by  the  new  method of oo::class.  The copied object will be of the same class as the source object, and
       will have all its per-object methods copied. If it is a class, it will also have all the class methods in
       the class copied, but it will not have any of its instances copied.

       After the targetObject has been created and all definitions of its configuration (e.g., methods, filters, │
       mixins) copied, the <cloned> method of targetObject will be invoked, to allow for  customization  of  the │
       created  object such as installing related variable traces. The only argument given will be sourceObject. │
       The default implementation of this method (in oo::object) just copies the procedures and variables in the │
       namespace  of sourceObject to the namespace of targetObject. If this method call does not return a result │
       that is successful (i.e., an error or other kind of exception) then the targetObject will be deleted  and │
       an error returned.

       The result of the oo::copy command will be the fully-qualified name of the new object or class.

EXAMPLES

       This  example  creates  an  object, copies it, modifies the source object, and then demonstrates that the
       copied object is indeed a copy.

              oo::object create src
              oo::objdefine src method msg {} {puts foo}
              oo::copy src dst
              oo::objdefine src method msg {} {puts bar}
              src msg              → prints "bar"
              dst msg              → prints "foo"

SEE ALSO

       oo::class(3tcl), oo::define(3tcl), oo::object(3tcl)

KEYWORDS

       clone, copy, duplication, object