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oo::util(n) Utility commands for TclOO oo::util(n) 





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



  

  
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.

  

  

  
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






  

  
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






  
  

  

  
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.





  

  
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)






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








  

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