New class base on book class with options

Question

I created a class of my own that uses book as base class.

\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{manuscript}[2013/03/23 Creative writing manuscripts class]
\LoadClass[a4paper,12pt,oneside]{book}

The problem is that I want to be able to choose paper size and other options the book class has. The only way to do that is to redefine all the options the book class already has with the same values and pass it when I load the base class?

Also, let's say I want to add a language option to my class so that if I choose Portuguese, for example, I want to load babel with portuguese.

How can I create use the options already defined in book class to change the values of that class and use my new Portuguese option to load babel with that language.

Answer 1

You can use

\DeclareOption*{\PassOptionsToClass{\CurrentOption}{book}}

to pass all not used option to your basic class book when it is called with \LoadClass{book}.

To give you a better advice you should add a MWE what you doing in your class.

Answer 2

To pass the options, use

\DeclareOption*{\PassOptionsToClass{\CurrentOption}{book}}
\ProcessOptions \relax
\LoadClass[12pt,a4paper,oneside]{book}

To pass a new option to another package (in this case babel)

\DeclareOption{english}{\AtEndOfClass{\main@language{english}}}
\DeclareOption{portuguese}{\AtEndOfClass{\main@language{portuges}}}
\RequirePackage[portuges, english]{babel}