Cfrgtkky

Consider the following mwe divided in 3 files:

main.tex:

documentclass[12pt]{report}



usepackage{subfiles}

newcommand{onlyinsubfile}[1]{#1}

newcommand{notinsubfile}[1]{}



usepackage{amsmath}



begin{document}



renewcommand{onlyinsubfile}[1]{}

renewcommand{notinsubfile}[1]{#1}



main:



begin{equation}label{eqn:main}

    1+1=2

end{equation}



subfile{subfile1}



end{document}

subfile1.tex:

documentclass[main.tex]{subfiles}



onlyinsubfile{

    usepackage{amsmath}

    usepackage{xr}

    externaldocument{main}

}



begin{document}



Subfile1 



begin{equation}

label{eqn:a}

    a= b+c

end{equation}



1: main ref: ref{eqn:main}



renewcommand{onlyinsubfile}[1]{}

renewcommand{notinsubfile}[1]{#1}

subfile{subfile2}



end{document}

subfile2.tex:

documentclass[main.tex]{subfiles}



onlyinsubfile{

    usepackage{amsmath}

    usepackage{xr}



    externaldocument{main} 

    externaldocument{subfile1} 

}



begin{document}



2: subfile ref: ref{eqn:a}



2: main ref ref{eqn:main}



end{document}

If I typeset main.tex I get (as expected)

The problem is that, if I compile subfile1.tex (or subfile2.tex) separately the reference numberings clash and I get the following:

subfile1.pdf:

subfile2.pdf:

Is there a way to get the proper numberings? In my example I only have a couple of equations, but in general I may have theorems, definitions and other environments, so it would probably be very tedious to "manually" initialize every counter at the beginning of each subfile.

You wish the same numbering both within the pdf-file that comes from compiling main.tex and in the pdf-files that come from compiling subfile1.tex / subfile2.tex?

If so, you need, when compiling subfile1.tex / subfile2.tex, to initialize the values of the counters to the values these counters have when compiling main.tex.

Solution 1:

For doing so, you can place labels and use a combination of the xr-package and Heiko Oberdiek's refcount-package.

You also may wish to have a mechanism for checking whether the reference in question is to be found in the same document or is to be found in the external main.pdf.

This might be especially useful when not using the xr-package but the hyperref-package and the xr-hyper-package as in this case you need to decide whether the hyperlink created by the reference has to go to the same document or to the external main.pdf.

In the example below, the mechanism is formed by localorexternallabel: This macro as argument takes the name of a label. In case the label is defined, that label-name will be used. In case it is not defined, the phrase coming from the macro labelprefix will be prepended to the label-name which implies referencing the label from the external (main) document.

main.tex

documentclass[12pt]{report}

usepackage{amsmath}

%%%%%

% Either:

%usepackage{xr-hyper}

%usepackage{hyperref}

% Or:

usepackage{xr}

%%%%% 

usepackage{refcount}

usepackage{subfiles}

newcommand{onlyinsubfile}[1]{#1}

newcommand{notinsubfile}[1]{}

newcommandlabelprefix{}

newcommandlocalorexternallabel[1]{%

  expandafterifxcsname r@#1endcsnamerelax

    labelprefix

  fi #1%

}





begin{document}



renewcommand{onlyinsubfile}[1]{}

renewcommand{notinsubfile}[1]{#1}



main:



begin{equation}label{eqn:main}

    1+1=2

end{equation}



subfile{subfile1}



end{document}

subfile1.tex

documentclass[main.tex]{subfiles}



onlyinsubfile{%

    csname @ifpackageloadedendcsname{xr-hyper}{%

      externaldocument[MAIN]{main}[main.pdf]% xr-hyper in use; optional argument for url of main.pdf for hyperlinks

    }{%

      externaldocument[MAIN]{main}% xr in use

    }%

    renewcommandlabelprefix{MAIN}%

    % Initialize the counters via the labels belonging to the main document:

    setcounter{equation}{numexprgetrefnumber{labelprefix eqn:a}-1relax}%

}



begin{document}



Subfile1 



begin{equation}

label{eqn:a}

    a= b+c

end{equation}



1: main ref: ref{localorexternallabel{eqn:main}}



renewcommand{onlyinsubfile}[1]{}

renewcommand{notinsubfile}[1]{#1}

subfile{subfile2}



end{document}

subfile2.tex

documentclass[main.tex]{subfiles}



onlyinsubfile{%

    csname @ifpackageloadedendcsname{xr-hyper}{%

      externaldocument[MAIN]{main}[main.pdf]% xr-hyper in use; optional argument for url of main.pdf for hyperlinks

    }{%

      externaldocument[MAIN]{main}% xr in use

    }%

    renewcommandlabelprefix{MAIN}%

    % Initialize the counters via the labels belonging to the main document:

    % - no counters used -

}



begin{document}



2: subfile ref: ref{localorexternallabel{eqn:a}}



2: main ref ref{localorexternallabel{eqn:main}}



end{document}

main.pdf

subfile1.pdf

subfile2.pdf

By the way: You might be interested in the includeonly-feature of the LaTeX 2e-kernel.

Solution 2:

When compiling subfile1.tex / subfile2.tex, you need to initialize the values of the counters to the values these counters have when compiling main.tex.

For doing this, you can borrow code from the LaTeX 2e-kernel's include-includeonly-mechanism for writing the values of all counters defined via newcounter into a referencing-label which is abused for performing many calls to setcounter instead of just delivering some numbers.

I suggest abusing a referencing-label for this because referencing-labels can be imported via externaldocument into sub-files.

I did this with the macro MoveCountersToOrFromLabel:

When it is used while compiling main.tex it will write setcounter-calls for all counter-values as a single referencing-label to the .aux-file.

When it is used while compiling a sub-file, it will retrieve the counter-values from the corresponding external label of main.aux.

As the collection of counter-values is saved by means of a referencing-label, that referencing-label needs to have a name. That name is the argument of MoveCountersToOrFromLabel.

Besides this:

Instead of macros onlyinsubfile / notinsubfile, you can within the preamble use @ifclassloaded for forking depending on whether the documentclass subfiles was loaded also, which is not the case when compiling main.tex.

main.tex

documentclass[12pt]{report}

usepackage{amsmath}



% Either:

usepackage{xr-hyper}

usepackage{hyperref}

% Or:

%usepackage{xr}



makeatletter

@ifundefined{@car}{newcommand@car{}longdef@car#1#2@nil{#1}}{}%

newcommandsetdefinedcounter[2]{%

  @ifundefined{c@#1}{newcounter{#1}}{}%

  setcounter{#1}{#2}%

}%

@ifclassloaded{subfiles}{%

  % Obviously we are in a sub-file as only sub-files load the subfile-class.

  @ifpackageloaded{xr-hyper}{%

    externaldocument[MAIN]{main}[main.pdf]% xr-hyper in use; optional argument for url of main.pdf for hyperlinks

  }{%

    externaldocument[MAIN]{main}% xr in use

  }%

  newcommandlabelprefix{MAIN}%

  %    Define MoveCountersToOrFromLabel to extract the referencing-label holding the

  %    counter-values. This label is imported from main.tex/main.aux, thus labelprefix

  %    is needed. The macro underlying that label is r@labelprefix<label-name> and

  %    we need the first undelimited argument of its expansion. This we grab via @car.

  newcommandMoveCountersToOrFromLabel[1]{%

    @bsphack

    % There are counters like section@level that get defined via

    % some hook (like AtBeginDocument) after the preamble, thus

    % check if still in preamble, and if so, apply the hook, too:

    ifx@onlypreamble@notprerr

      expandafter@firstoftwo

    else

       expandafter@secondoftwo

    fi{@firstofone}{AtBeginDocument}%

    {%

      @ifundefined{r@labelprefix#1}{}{%

        expandafterexpandafterexpandafter@carcsname r@labelprefix#1endcsname@nil

      }%

    }%

    @esphack

  }%

}{%

  % Obviously we are in the main document as the main document does not load the subfile-class.

  newcommandlabelprefix{}%

  %    Define MoveCountersToOrFromLabel to write counter-values to referencing-label:

  newcommandMoveCountersToOrFromLabel[1]{%

    @bsphack

    if@filesw 

      protected@write@auxout{%

        letsavedwritewrite

        defwrite{immediatesavedwrite}%

        def@elt##1{%

          stringprotect

          stringsetdefinedcounter{##1}{the@nameuse{c@##1}}@percentchar^^J%

        }%

      }{%

        stringnewlabel{#1}{{@percentchar^^Jcl@@ckpt}{}{}{}{}}%

      }%

    fi

    @esphack

  }%

}%

% Check whether the label in question is available in the current document or whether it

% needs to be retrieved from the external main.pdf/main.aux:

newcommandlocalorexternallabel[1]{%

  expandafterifxcsname r@#1endcsnamerelax

    labelprefix

  fi#1%

}%

makeatother



usepackage{subfiles}



begin{document}



main:



begin{equation}label{eqn:main}

    1+1=2

end{equation}



subfile{subfile1}



end{document}

subfile1.tex

documentclass[main.tex]{subfiles}

MoveCountersToOrFromLabel{subfile1}

begin{document}



Subfile1 



begin{equation}

label{eqn:a}

    a= b+c

end{equation}



1: main ref: ref{localorexternallabel{eqn:main}}



subfile{subfile2}



end{document}

subfile2.tex

documentclass[main.tex]{subfiles}

MoveCountersToOrFromLabel{subfile2}

begin{document}



2: subfile ref: ref{localorexternallabel{eqn:a}}



2: main ref ref{localorexternallabel{eqn:main}}



end{document}

main.pdf

subfile1.pdf

subfile2.pdf