Customize package between book/article classes

Question

I wrote a small package that I used to typeset a book. Now, I'd like to reuse it for smaller documents. The package uses tcolorbox and defines a box like this:

\newtcblisting[auto counter,
               number within=chapter,
               crefname={Lis.}{Lis.},
               ...

The only thing I need to change when writing shorter documents is to remove the line number within=chapter.

I'm not sure how to achieve that. What's the best way:

• Use an if to somehow test if counter chapter is defined?
• Use an if to somehow test the document class (e.g., book vs article)?
• Add an option to the package and test it to include/exclude number within?

I have very little experience developing packages, and I'll welcome any help on this question.

Thanks in advance.

Answer 1

you can check for document class, by name but more general is to check for \chapter

\@ifundefined{chapter}
  {no chapter version}
   {chapter version}