[//000000001]: # (oo::util \- Utility commands for TclOO)
[//000000002]: # (Generated from file 'ooutil\.man' by tcllib/doctools with format 'markdown')
[//000000003]: # (Copyright © 2011\-2015 Andreas Kupries, BSD licensed)
[//000000004]: # (oo::util\(n\) 1\.2\.2 tcllib "Utility commands for TclOO")
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# NAME
oo::util \- Utility commands for TclOO
# Table Of Contents
- [Table Of Contents](#toc)
- [Synopsis](#synopsis)
- [Description](#section1)
- [COMMANDS](#section2)
- [AUTHORS](#section3)
- [Bugs, Ideas, Feedback](#section4)
- [See Also](#seealso)
- [Keywords](#keywords)
- [Category](#category)
- [Copyright](#copyright)
# SYNOPSIS
package require Tcl 8\.5
package require TclOO
package require oo::util ?1\.2\.2?
[__mymethod__ *method* ?*arg*\.\.\.?](#1)
[__classmethod__ *name* *arguments* *body*](#2)
[__classvariable__ ?*arg*\.\.\.?](#3)
[__link__ *method*\.\.\.](#4)
[__link__ \{*alias* *method*\}\.\.\.](#5)
[__ooutil::singleton__ ?*arg*\.\.\.?](#6)
# 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](\.\./snit/snit\.md)__ 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](\.\./snit/snit\.md)__ 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](\.\./snit/snit\.md)__ 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\(n\)](\.\./snit/snit\.md)
# KEYWORDS
[TclOO](\.\./\.\./\.\./\.\./index\.md\#tcloo),
[callback](\.\./\.\./\.\./\.\./index\.md\#callback), [class
methods](\.\./\.\./\.\./\.\./index\.md\#class\_methods), [class
variables](\.\./\.\./\.\./\.\./index\.md\#class\_variables), [command
prefix](\.\./\.\./\.\./\.\./index\.md\#command\_prefix),
[currying](\.\./\.\./\.\./\.\./index\.md\#currying), [method
reference](\.\./\.\./\.\./\.\./index\.md\#method\_reference), [my
method](\.\./\.\./\.\./\.\./index\.md\#my\_method),
[singleton](\.\./\.\./\.\./\.\./index\.md\#singleton)
# CATEGORY
Utility
# COPYRIGHT
Copyright © 2011\-2015 Andreas Kupries, BSD licensed