TIP:		354
Title:		Minor Production-Driven TclOO Revisions
State:		Final
Type:		Project
Tcl-Version:	8.6
Vote:		Done
Post-History:	
Version:	$Revision: 1.4 $
Author:		Donal K. Fellows <dkf@users.sf.net>
Created:	26-Aug-2009

~ Abstract

This TIP describes a few small changes required for solving issues that have
been found when using TclOO in production.

~ Description

TclOO (see [257]) has now had a substantial amount of use for relatively
complex functionality (as well as production deployment) and it has turned out
that there were a few small changes required.

 1. The scope of resolution for the target of a '''forward'''ed method is
    updated so that it is with respect to the object's namespace. This means
    that a class may create methods that forward to a command given by each
    instance, which makes creating megawidgets by wrapping real Tk widgets
    much easier, since the forwards do not have to be created at the instance
    level.

 2. A subcommand was added to '''info object''' to allow the discovery of the
    namespace of an object by code outside that object. This makes it far
    easier for code that needs to "break the abstraction" to do so, which
    turns out to be necessary for things like serialization. This subcommand,
    '''namespace''', takes an object name as its only argument and returns the
    name of the object's namespace.

  > To expand on the requirements for serialization, the serialization code
    needs to call a method on each object to create the serialization for that
    object. However, the method should not be part of the public API for the
    object as it cannot perform a complete serialization correctly, since the
    serialization depends on the rest of the object graph. (It also requires a
    number of global overheads that are best applied once, not repeatedly.)

  > Note that I plan to release the serialization code itself (originally
    developed as part of a solution for a Rosetta Code task) as a package via
    tcllib. This TIP does not propose its inclusion with Tcl.

 3. A new C API function has been added to allow code at that level to
    ''efficiently'' discover the name of an object that it already has a
    handle to. This new function, '''Tcl_GetObjectName''', returns a shared
    Tcl_Obj reference to the name that needs no special reference count
    management.

~ Copyright

This document has been placed in the public domain.
