NAME

       oo::util - Utility commands for TclOO

SYNOPSIS

       package require Tcl  8.5

       package require TclOO

       package require oo::util  ?1.1?

       mymethod method ?arg...?

       classmethod name arguments body

       classvariable ?arg...?

       ooutil::singleton ?arg...?

_________________________________________________________________

DESCRIPTION

       This package provides a convenience command for the easy specification of instance methods
       as callback commands, like timers, file events, Tk bindings, etc.

COMMANDS

       mymethod method ?arg...?
              This command is available within instance methods. It  takes  a  method  name  and,
              possibly,  arguments  for  the  method  and  returns  a  command prefix which, when
              executed, will invoke the named method of the object we are in, with  the  provided
              arguments, and any others supplied at the time of actual invokation.

              Note:  The  command is equivalent to and named after the command provided by the OO
              package snit for the same purpose.

       classmethod name arguments body
              This command is available within class definitions. It takes  a  method  name  and,
              possibly,  arguments for the method and creates a method on the class, available to
              a user of the class and of derived classes.

              Note: The command is equivalent to  the  command  typemethod  provided  by  the  OO
              package snit for the same purpose.

              Example
              oo::class create ActiveRecord {
              classmethod find args { puts "[self] called with arguments: $args" }
              }
              oo::class create Table {
              superclass ActiveRecord
              }
              puts [Table find foo bar]
              # ======
              # which will write
              # ======
              # ::Table called with arguments: foo bar

       classvariable ?arg...?
              This  command  is  available within instance methods. It takes a series of variable
              names and makes them available in the method's scope. The originating scope for the
              variables  is  the class (instance) the object instance belongs to. In other words,
              the referenced variables are shared between all instances of their class.

              Note: The command is roughly equivalent to the command typevariable provided by the
              OO  package  snit for the same purpose. The difference is that it cannot be used in
              the class definition itself.

              Example:
              % oo::class create Foo {
              method bar {z} {
              classvariable x y
              return [incr x $z],[incr y]
              }
              }
              ::Foo
              % Foo create a
              ::a
              % Foo create b
              ::b
              % a bar 2
              2,1
              % a bar 3
              5,2
              % b bar 7
              12,3
              % b bar -1
              11,4
              % a bar 0
              11,5

       ooutil::singleton ?arg...?
              This command is a meta-class, i.e. a variant of the builtin oo::class which ensures
              that it creates only a single instance of the classes defined with it.

              Syntax and results are like for oo::class.

              Example:
              % oo::class create example {
              self mixin singleton
              method foo {} {self}
              }
              ::example
              % [example new] foo
              ::oo::Obj22
              % [example new] foo
              ::oo::Obj22

AUTHORS

       Donal Fellows, Andreas Kupries

BUGS, IDEAS, FEEDBACK

       This  document,  and  the  package  it  describes, will undoubtedly contain bugs and other
       problems.  Please report  such  in  the  category  oo::util  of  the  Tcllib  SF  Trackers
       [http://sourceforge.net/tracker/?group_id=12883].    Please  also  report  any  ideas  for
       enhancements you may have for either package and/or documentation.

SEE ALSO

       snit(3tcl)

KEYWORDS

       TclOO,  callback,  class  methods,  class  variables,  command  prefix,  currying,  method
       reference, my method, singleton

CATEGORY

       Utility

COPYRIGHT

       Copyright (c) 2011-2013 Andreas Kupries, BSD licensed