What is a good strategy to internationalize a document class?

Question

I am busy with a new document class and I have been trying my hand in internationalizing some of the contents. I have tried using translator from Beamer. Is this a good strategy? Can the code shown below be improved? Are there any other options to carry out such a task?

%% The article class
\documentclass[oneside]{book}
\usepackage[paperwidth=4.75in,paperheight=7.25in,
            textwidth=4.5in,textheight=6.5in,
            headsep=0.1in, footskip=0.15in,
            marginratio=1:1]{geometry}
\usepackage[dutch,greek,english]{babel}
\usepackage{filecontents,xspace}
\usepackage{translator}

%% just to allow filenames to be changed easily
\def\fname{mothererror}

%% The Greek dictionary file
\begin{filecontents*}{\fname-Greek.dict}
\ProvidesDictionary{\fname}{Greek}
\providetranslation{mother}{mht`era `olwn t`wn laj`wn}
\providetranslation{Error}{L`ajos}
\providetranslation{Errors}{L`ajh}
\end{filecontents*}

%% The Dutch dictionary file
\begin{filecontents*}{\fname-Dutch.dict}
\ProvidesDictionary{\fname}{Dutch}
\providetranslation{mother}{moeder van alle fouten}
\providetranslation{error}{fout}
\providetranslation{Error}{Fout}
\providetranslation{Errors}{Fouten}
\end{filecontents*}

%% The English dictionary file
\begin{filecontents*}{\fname-English.dict}
\ProvidesDictionary{\fname}{English}
\providetranslation{mother}{mother of all errors}
\providetranslation{error}{error}
\providetranslation{Error}{Error}
\providetranslation{Errors}{Errors}
\end{filecontents*}

%% The package file mothererror.sty
%% internationlizes mother of all errors!
\begin{filecontents*}{\fname.sty}
%% Now declare what environment we need:
\NeedsTeXFormat{LaTeX2e}[1994/12/01]
%% Load the translator package
\RequirePackage{translator}
\usedictionary{\fname}
%% create a test error for package
\def\geterror#1{\translate{Error} #1 : 
\ifcase #1\or 
    1 A general error\or
    \ldots\translate{mother}\xspace\or
 \fi}
\end{filecontents*}

%% Load the package we just saved
\usepackage{\fname}
\uselanguage{dutch,greek,english}
\begin{document}
%% Dutch
\selectlanguage{dutch}
\chapter{\translate{Errors}}
Dutch: \geterror{2}, \today
%% English
\selectlanguage{english}
\chapter{Errors}
English: \geterror{2},  \today
%% Greek
\selectlanguage{greek}
\chapter{\translate{Errors}}
Ellhnik'a: \geterror{2} \today
\end{document}

Answer 1

An alternative would be, to use package scrbase from KOMA-Script. It seems the chapter about this package is missing at scrguien.pdf. Here is an example:

\documentclass[oneside]{book}
\usepackage[paperwidth=4.75in,paperheight=7.25in,
  textwidth=4.5in,textheight=6.5in, headsep=0.1in, footskip=0.15in,
  marginratio=1:1]{geometry} 
\usepackage[dutch,greek,english]{babel}
\usepackage{filecontents,xspace} 
\usepackage{scrbase}

\begin{filecontents*}{mothererror.sty}
\NeedsTeXFormat{LaTeX2e}[1994/12/01]
\ProvidesPackage{mothererror}[2011/11/01 v0.1 demo package]
\RequirePackage{xspace} 
\AtBeginDocument{%
  \providecaptionname{english}\mothername{mother}%
  \providecaptionname{english}\errorname{error}%
  \providecaptionname{english}\errorsname{errors}%
  \providecaptionname{greek}\mothername{mht`era `olwn t`wn laj`wn}%
  \providecaptionname{greek}\errorname{L`ajos}%
  \providecaptionname{greek}\errorsname{L`ajh}%
  \providecaptionname{dutch}\mothername{moeder van alle fouten}%
  \providecaptionname{dutch}\errorname{fout}%
  \providecaptionname{dutch}\errorsname{fouten}% 
}

\def\geterror#1{\expandafter\MakeUppercase\errorname~#1:  
  \ifcase #1
    \PackageError{mothererror}{unknown error number #1!}{}%
  \or
    A general error\or \ldots\mothername\xspace
  \else 
    \PackageError{mothererror}{unknown error number #1!}{}%
  \fi 
}
\endinput
\end{filecontents*}

%% Load the package we just saved 
\usepackage{mothererror}

\begin{document}
\tableofcontents %% Dutch 
\selectlanguage{dutch}
\chapter{\expandafter\MakeUppercase\errorsname} 
Dutch: \geterror{2},
\today 
%% English 
\selectlanguage{english}
\chapter{\expandafter\MakeUppercase\errorsname} 
English: \geterror{2},
\today 
%% Greek \selectlanguage{greek}
\chapter{\expandafter\MakeUppercase\errorsname} 
Ellhnik'a: \geterror{2}
\today
\end{document}

There are also commands \newcaptionname and \renewcaptionname.

BTW: I've use \expandafter\MakeUppercase to change the case of the first letter of a term. So you need terms like "error" only once instead of twice. It's only a little trick, but it's often useful.