Referencing the file itself - where the label comes from

[pauloney]

Is it possible to change the example in section 11.8 of the manual to use zref-clever with zref-xr in a way one can reference the file itself, that contains the label?

I have 2 volumes of a book, and refer to them as "Volume 1" and "Volume 2", and would like to be able from one of the volumes to refer to the other and obtain a result like:

... according to the Proposition 2.3 of Volume 1...

(without having to enter the number of the volume that contains the label.)

[gusbrs]

Hi @pauloney , that's not really a feature of xr, hence also not of zref-xr. What comes imported from the external file is the url property, which in the example would be the name of the file. You can't see it in the aux file, but in the manual example 11.8, if you add to the main file:

\ExplSyntaxOn
\tl_show:c{Z@R@B-sec:section-b1}
\ExplSyntaxOff

You'll find in the log:

> \Z@R@B-sec:section-b1=\default {1}\page {1}\abspage {1}\zc@counter
{section}\thecounter {1}\zc@type {section}\zc@cntval {1}\zc@pgval
{1}\zc@enclval {}\zc@pgfmt {1}\anchor {section.1}\externaldocument
{documentB}\url {documentB.pdf}.

The url is documentB.pdf. I guess you could use the externaldocument property, if you actually named your file Volume 2.tex.

Something like:

\documentclass{article}
\usepackage{zref-clever}
\usepackage{zref-xr}
\zexternaldocument[B-]{documentB}
\usepackage{hyperref}
\begin{document}
\section{Section A1}
\zlabel{sec:section-a1}
\zcref{B-sec:section-b1} of \zref[externaldocument]{B-sec:section-b1}
\end{document}

Or you could use zref facilities and actually build whatever you want. For example:

\documentclass{article}
\usepackage{zref-clever}
\usepackage{zref-xr}
\zexternaldocument[B-]{documentB}
\usepackage{hyperref}
\begin{document}
\section{Section A1}
\zlabel{sec:section-a1}
\zcref{B-sec:section-b1} of \zref[volume]{B-sec:section-b1}
\end{document}

and

\documentclass{article}
\usepackage{zref-clever}
\makeatletter
\zref@newprop{volume}{Volume 2}
\zref@addprop{main}{volume}
\makeatother
\usepackage{hyperref}
\begin{document}
\section{Section B1}
\zlabel{sec:section-b1}
\end{document}

But, again, this is not really a typical use of xr, even if interesting in itself, so I don't see a reason to change anything in the manual.