How to cross-reference labels between two documents without hyperlinks, while still creating hyperlinks to labels within the same document?

Question

I have two documents (A and B) with labels. I would like to reference the labels in document A from document B. I would like to use the hyperref package to create hyperlinks in document B to the labels within document B. I want to resolve the references in document B to document A with the correct numbering, but I do not want to create hyperlinks for theses references. Is this possible? My motivation is that document A is being published on an external site, so I can't link to references within it and I don't want broken hyperlinks.

• If I use the xr-hyper package (a great minimal example is available in this answer to the question "Does hyperref work between two files?"), LaTeX will create a link to document A from document B when document B references a label in document A.
• If I use the xr package instead of xr-hyper, LaTeX will create a hyper link to label 1 of document B when document B references label 1 of document A (i.e. it still tries to create hyperlinks but it does not link them outside of the document).

For a full minimal working example, look at this adapted version of the example given in the answer here:

docA.tex

\documentclass{article} 
\usepackage{xr-hyper} 
\usepackage{hyperref} 
\externaldocument[B-]{docB}[docB.pdf]% <- full or relative path 
\begin{document}
    This is a test for math.
    \begin{equation}
        E=mc^2 \label{eq:1}
    \end{equation}
    This is a second test for math.
    \begin{equation}
        r = \sqrt{x^2 + y^2} \label{eq:2}
    \end{equation}
    In document B Eq.~~(\ref{B-eq:x}) 
\end{document}

docB.tex

\documentclass{article}
\usepackage{xr-hyper}
\usepackage{hyperref}
\externaldocument[A-]{docA}[docA.pdf]% <- full or relative path
\begin{document}
  \setcounter{equation}{5}

  As was shown in Eq.~(\ref{A-eq:1}) is it
  ... or in Eq.~(\ref{A-eq:2}) is ...
  \begin{equation}
    \mathrm{e}^{i\pi}-1=0 \label{eq:x}
  \end{equation}

  Here is a hyperlinked internal reference to \ref{eq:x}.
\end{document}

I want to produce a pdf with the first \ref in document B turned into a "1" but not hyperlinked to an external document and the last \ref in document B turned into a "6" and hyperlinked to eq:x.

Answer 1

Thanks for posting an example with compilable code. As @UlrikeFischer has pointed out in an earlier comment, if the hyperref package is loaded, you should use \ref* instead of \ref to create a cross-reference that's not also a hypertarget. Please note that this applies regardless of whether the cross-reference's target is located in the same document or in some other document.

Still assuming that hyperref is loaded, one should use \autoref* rather than \autoref to create cross-references that (a) automatically provide the name of the item being cross-referenced (e.g., "section", "figure", "footnote", etc) as part of the call-out and (b) aren't hypertargets. Likewise, if the cleveref package is loaded in addition to the hyperref package, one should use \cref* and \Cref* instead of \cref and \Cref to create "clever" cross-references that aren't also hypertargets.

Answer 2

My idea is:

1. to patch the xr-hyper package so that it records all labels that it read from external documents; this allows us to distinguish between internal references that should be automatically hyperlinked and external references that should not.
2. to redefine the unstarred version of hyperref's \ref to check whether the reference is external or not, and to essentially assume that the starred version was used if so.

I believe the following does what you want, changes only necessary to docB.tex:

\documentclass{article}
\usepackage{xr-hyper}
\usepackage{hyperref}


% following code is to meet objectives of [How to cross-reference labels between two documents without hyperlinks, while still creating hyperlinks to labels within the same document?](http://tex.stackexchange.com/questions/112603/how-to-cross-reference-labels-between-two-documents-without-hyperlinks-while-st)
% insert this after loading xr-hyper and hyperref but before calling \externaldocument
\makeatletter
% patch XR so that it records whether or not the label has come from an external file
\long\def\XR@test#1#2#3#4\XR@{%
  \ifx#1\newlabel
     \expandafter\protected@xdef\csname r@\XR@prefix#2\endcsname
       {\XR@addURL{#3}}%
     \expandafter\protected@xdef\csname isxr@r@\XR@prefix#2\endcsname{1}%
  \else\ifx#1\@input
     \edef\XR@list{\XR@list\filename@area#2\relax}%
  \fi\fi
  \ifeof\@inputcheck\expandafter\XR@aux
  \else\expandafter\XR@read\fi}

% every time \ref is used without an explicit star, check if it is an external reference or not
\AtBeginDocument{%
    \let\orig@T@ref\T@ref
    %patched \T@ref checks if the ref is from xr, and redirects to \@refstar if so
    % else it passes to \orig@T@ref
    \def\T@ref#1{%
        \ifcsname isxr@r@#1\endcsname
            %\typeout{sending #1 to refstar}%
            \@refstar{#1}%
        \else
            %\typeout{sending #1 to orig@T@ref}%
            \orig@T@ref{#1}%
        \fi
    }%
}%
\makeatother
% end patch

\externaldocument[A-]{docA}[docA.pdf]% <- full or relative path
\begin{document}
  \setcounter{equation}{5}

  As was shown in Eq.~(\ref{A-eq:1}) is it
  ... or in Eq.~(\ref{A-eq:2}) is ...
  \begin{equation}
    \mathrm{e}^{i\pi}-1=0 \label{eq:x}
  \end{equation}

  Here is a hyperlinked internal reference to \ref{eq:x}.
\end{document}

Output:

Note that this may not play well with other packages that hook into \ref etc.