[Tex/LaTex] Best practice for setting package options through class options

class-optionsdocumentclass-writingpackage-options

I want to process my class options so as to create a (potentially long) options list for package(s) I'm loading, e.g.

% set default package options here somehow
\DeclareOption{myvariant}{
    % set a bunch of alternative options overriding the default
}

\RequirePackage[some kind of magic should go here]{mypackage}

Specifically, I thought maybe I should be using PassOptionsToClass, but then – how do I prevent the default action?

Right now I'm doing something else, and kind of ugly, which relies on my specific package of interest (geometry) allowing doing everything with a command rather than a package option:

\newcommand{\iitcs@geometry{\geometry{key=val,key2=val2}}
\DeclareOption{myopt}{
 \renewcommand{\iitcs@geometry{\geometry{key=val3,key3=val4}}
}
%...
\RequirePackage{geometry}
\iitcs@geometry

(edit) I'll emphasize that I'd like a solution for the case I have no choice but to provide the right package options, with no flexibility like with `geometry'.

Best Answer

You can use \geometry and options therein multiple times. So for this application I suggest something like

\DeclareOption{myopt}{%
  \AtEndOfPackage{\geometry{paperwidth=3cm,paperheight=9cm}}}

\ProcessOptions\relax
\RequirePackage{geometry}
\geometry{paperwidth=12cm,paperheight=12cm} % default

In more general cases it may be more difficult, because options are executed in the order they are listed in the package, when it calls \ProcessOptions.

So if packageB.sty declares x and nox in this order (later using \ProcessOptions, not \ProcessOptions*) and you say in packageA.sty

\DeclareOption{x}{\PassOptionsToPackage{x}{packageB}}
\DeclareOption{nox}{\PassOptionsToPackage{nox}{packageB}}

\ExecuteOptions{nox}
\ProcessOptions\relax
\RequirePackage{packageB}

then nox will be executed last by packageB no matter if you call packageA with the x option.

So a more precise answer depends on "real world" situations.

Related Solutions

[Tex/LaTex] Setting class options after \documentclass

Yes, but like many of the kernel class options it was not exactly designed for this. You'd by much better off simply having two potential document class lines, or something as simple as

\documentclass[
   twoside
 ]{book}

so you can comment out the option as necessary.

[Tex/LaTex] Changing the default options of a document class

You could declare a string option that accepts the font size and defaults to 11pt. However, this will come at the expense of the top class no longer being aware of what exactly it is doing. But that's a principal problem of upwards compatibility. E.g.

\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{atop}[16/07/2011]

\RequirePackage{kvoptions}
% Declare a string option `fntsize' that is unique to the derived
% class `atop'. It will accept anything assuming `11pt' if
% unspecified.
\DeclareStringOption[11pt]{fntsize}
% probably more options...
\ProcessKeyvalOptions{atop}\relax
\PassOptionsToClass{\atop@fntsize}{article}

% Assume that any unknown option will be understood by the base class:
\DeclareOption*{%
  \PassOptionsToClass{\CurrentOption}{article}%
}
\ProcessOptions\relax

% Now load the base class with the `fntsize' option and any unknown
% option:
\LoadClass{article}

If you happen to be the author of the base class and hence have the freedom to make it "a good base class", you might do some fancier things. For example, you could add a macro that allows executing options after the class has been loaded. (Like hyperref's \hypersetup or geometry's \geometry.) Then you could further add a macro, say \getOptionList, that returns a comma separated list of all options. You may then retrieve the list of options accepted by the base class in the derived class and use it to make further decisions without hardcoding the status quo of base options.

Best

Best Answer

Related Solutions

[Tex/LaTex] Setting class options after \documentclass

[Tex/LaTex] Changing the default options of a document class

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