position property in Location object

[838]

Could the position property hold an index value of the readingOrder?

https://readium.org/architecture/models/locators

[mickael-menu]

Yes, that's basically what is done for comic books. But you need to start the position index at 1 instead of 0. The reason is that this is used for display purposes, similar to page numbers.

[838]

@mickael-menu Thank you 🙏

[jerome65536]

Not sure whether an integer chapter index is suitable for chapter numbers for display purposes in general — what about chapter numbers such as Preface, III, II, I, Table of contents, 1, 2, 3, Appendix A.

[mickael-menu]

Quoting the position list specification:

While reading a publication, users may need to reference or access a specific position.

While some formats have an implicit (image based publications) or an optional explicit option (EPUB 3.x) to express such references, clients need references even for publication formats that do not provide anything.

You can view the position property as something similar to a physical page number, it's not a "chapter number".

So in the case of comic books, it makes sense to have one position per reading order item. For reflowable formats like EPUB, you will likely have multiple positions per resource. See this issue for some implementation guidelines.