This is essentially the same question: Write a class with language dependent strings. But I didn't find any solutions that worked.
I'm trying to create a package where languages are package options, like so:
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{mypackage}[2019]
\RequirePackage[utf8]{inputenc}
\RequirePackage{babel}
\DeclareOption{nynorsk}{
\PassOptionToPackage{main=nynorsk}{babel}
%\AtEndOfClass{\main@language{nynorsk}}
} % Gir pakken med nynorsk babel
\DeclareOption{bokmål}{
\PassOptionToPackage{main=norsk}{babel}
%\AtEndOfClass{\main@language{norsk}}
} % Gir pakken med bokmål babel
\DeclareOption{english}{
\PassOptionToPackage{main=english}{babel}
%\AtEndOfClass{\main@language{english}}
} % Gives the package with english babel
\DeclareOption*{\PackageWarning{examplepackage}{Unknown ‘\CurrentOption’}} % for unknown input
\ProcessOptions\relax
\endinput
In a document it would look something like this:
\documentclass{article}
\usepackage[english]{mypackage}
\beging{document}
Hello, this is a document
\end{document}
I get this error on the line \usepackage[english]{mypackage} in the document:
LaTeX Error: Unknown option `english' for package `mypackage*. Missing
= inserted for \infum. Missing numer,treated as zero.
and on the line with \begindocument I get this error:
LaTeX error: \RequirePackage or \LoadClass in Options section
So how can I create a multilingual package with language options?
edit: What I try to do is including the babel package in mypackage such that I can write:
\usepackage[english]{mypackage}
instead of:
\usepakckage{mypackage}
\usepackage[english]{babel}