NAME

       oo::util - Utility commands for TclOO

SYNOPSIS

       package require Tcl  8.5

       package require TclOO

       package require oo::util  ?1.2.2?

       mymethod method ?arg...?

       classmethod name arguments body

       classvariable ?arg...?

       link method...

       link {alias method}...

       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

       link method...

       link {alias method}...
              This command is available within instance methods. It takes a list of method names and/or pairs of
              alias-  and  method-name  and  makes  the  named methods available to all instance methods without
              requiring the my command.

              The alias name under which the method becomes available defaults to the method name, except  where
              explicitly specified through an alias/method pair.

              Examples:

                  link foo
                  # The method foo is now directly accessible as foo instead of my foo.

                  link {bar foo}
                  # The method foo is now directly accessible as bar.

                  link a b c
                  # The methods a, b, and c all become directly acessible under their
                  # own names.

              The  main  use  of this command is expected to be in instance constructors, for convenience, or to
              set up some methods for use in a mini DSL.

       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  Trackers  [http://core.tcl.tk/tcllib/reportlist].
       Please also report any ideas for enhancements you may have for either package and/or documentation.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note  further  that  attachments  are strongly preferred over inlined patches. Attachments can be made by
       going to the Edit form of the ticket immediately after its creation, and then using the left-most  button
       in the secondary navigation bar.

SEE ALSO

       snit(3tcl)

KEYWORDS

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

CATEGORY

       Utility

COPYRIGHT

       Copyright (c) 2011-2015 Andreas Kupries, BSD licensed