Biblatex, authoryear-comp, and hyperlinks

Question

In answer to this question, Audrey offered an answer that works great with the authoryear option.

(Context: I'm trying to get the hyperlink in citations to include the name of the author, and not just the year. Audrey provided a solution that works with authoryear, and I'm trying to adapt it to work with authoryear-comp.)

I'm trying to adapt the answer to make it work with authoryear-comp. Here is what I tried (it doesn't work---I get an error message: Latex Error: ./biblatex.tex:96 Argument of \@secondoftwo has an extra }. Runaway argument?):

\renewbibmacro*{cite}{%
\printtext[bibhyperref]{% Enclose cite macro output in hyperlink
    \global\togglefalse{cbx:hyperref}% Prevent nested hyperlinks
  \iffieldundef{shorthand}
    {\ifthenelse{\ifnameundef{labelname}\OR\iffieldundef{labelyear}}
       {\usebibmacro{cite:label}%
    \setunit{\addspace}%
    \usebibmacro{cite:labelyear+extrayear}%
        \usebibmacro{cite:reinit}}
       {\iffieldequals{namehash}{\cbx@lasthash}
          {\ifthenelse{\iffieldequals{labelyear}{\cbx@lastyear}\AND
                       \(\value{multicitecount}=0\OR\iffieldundef{postnote}\)}
             {\setunit{\addcomma}%
              \usebibmacro{cite:extrayear}}
             {\setunit{\compcitedelim}%
              \usebibmacro{cite:labelyear+extrayear}%
              \savefield{labelyear}{\cbx@lastyear}}}
          {\printnames{labelname}%
       \setunit{\nameyeardelim}%
           \usebibmacro{cite:labelyear+extrayear}%
           \savefield{namehash}{\cbx@lasthash}%
           \savefield{labelyear}{\cbx@lastyear}}}}
    {\usebibmacro{cite:shorthand}%
     \usebibmacro{cite:reinit}}%
\global\toggletrue{cbx:hyperref}}
  \setunit{\multicitedelim}}

I don't fully understand how \cite works under authoryear-comp, so maybe someone who does can see a way to do this? (I'm assuming it's possible, since this is how hyperlinks are implemented in BibTeX.)

EDIT (in re: to Marco's comment): Here's a minimal example:

\documentclass{article} 
\usepackage[utf8]{inputenc} 
\usepackage[style=authoryear-comp]{biblatex} 
\usepackage[colorlinks]{hyperref} 
\bibliography{biblatex-examples} 


\newtoggle{cbx:hyperref}
\toggletrue{cbx:hyperref}

\DeclareFieldFormat{bibhyperref}{% Adapted from bibhyperref format in biblatex.def
\iftoggle{cbx:hyperref}
{\bibhyperref{#1}}
{#1}}


\renewbibmacro*{cite}{%
\printtext[bibhyperref]{% Enclose cite macro output in hyperlink
    \global\togglefalse{cbx:hyperref}% Prevent nested hyperlinks
  \iffieldundef{shorthand}
    {\ifthenelse{\ifnameundef{labelname}\OR\iffieldundef{labelyear}}
       {\usebibmacro{cite:label}%
    \setunit{\addspace}%
    \usebibmacro{cite:labelyear+extrayear}%
        \usebibmacro{cite:reinit}}
       {\iffieldequals{namehash}{\cbx@lasthash}
          {\ifthenelse{\iffieldequals{labelyear}{\cbx@lastyear}\AND
                       \(\value{multicitecount}=0\OR\iffieldundef{postnote}\)}
             {\setunit{\addcomma}%
              \usebibmacro{cite:extrayear}}
             {\setunit{\compcitedelim}%
              \usebibmacro{cite:labelyear+extrayear}%
              \savefield{labelyear}{\cbx@lastyear}}}
          {\printnames{labelname}%
       \setunit{\nameyeardelim}%
           \usebibmacro{cite:labelyear+extrayear}%
           \savefield{namehash}{\cbx@lasthash}%
           \savefield{labelyear}{\cbx@lastyear}}}}
    {\usebibmacro{cite:shorthand}%
     \usebibmacro{cite:reinit}}%
\global\toggletrue{cbx:hyperref}}
  \setunit{\multicitedelim}}

\DeclareCiteCommand{\textcite}% Adapted from \textcite command in authoryear.cbx
  {\boolfalse{cbx:parens}}
  {\usebibmacro{citeindex}%
  \printtext[bibhyperref]{% Enclose textcite macro output in hyperlink
    \global\togglefalse{cbx:hyperref}% Prevent nested hyperlinks
    \usebibmacro{textcite}%
    \iffieldundef{postnote}% Include closing parenthesis if no postnote
      {\ifbool{cbx:parens}
         {\bibcloseparen\global\boolfalse{cbx:parens}}
      {}}
   {}}%
 \global\toggletrue{cbx:hyperref}}
 {\ifbool{cbx:parens}
 {\bibcloseparen\global\boolfalse{cbx:parens}}
 {}%
  \multicitedelim}
 {\iffieldundef{postnote}
  {}
 {\usebibmacro{textcite:postnote}}}

\begin{document} 
A reference to \parencite{kastenholz,sigfridsson} and~\cite{sigfridsson}. 
\printbibliography 
\end{document}

I'm using references from the biblatex-example database. The error I get is this: Paragraph ended before \@secondoftwo was complete.

Answer 1

Both \cite and \textcite use \setunit inside the <loopcode> argument of \DeclareCiteCommand. Links will include punctuation if you simply wrap <loopcode> (or the cite and textcite bibliography macros) in \bibhyperref. Moreover printing of \setunit is deferred to the next \print* or \bibstring command. So it is difficult to ensure that this approach will create links that point to the correct item in the bibliography.

The following patches to cite will make a single link for labelname/label and labelyear+extrayear where appropriate. The patches to textcite will include the parentheses around labelyear+extrayear in the absence of prenote, postnote and citation lists. Otherwise separate links are applied, similar to the citation links obtained with natbib.

\documentclass{report}
\usepackage[style=authoryear-comp]{biblatex}
\usepackage{hyperref}
\usepackage{xpatch}
% Just for demo
\ExecuteBibliographyOptions{maxcitenames=1}
% Combine label and labelyear links
\xpatchbibmacro{cite}
  {\usebibmacro{cite:label}%
   \setunit{\printdelim{nonameyeardelim}}%
   \usebibmacro{cite:labeldate+extradate}}
  {\printtext[bibhyperref]{%
     \DeclareFieldAlias{bibhyperref}{default}%
     \usebibmacro{cite:label}%
     \setunit{\printdelim{nonameyeardelim}}%
     \usebibmacro{cite:labeldate+extradate}}}
  {}
  {\PackageWarning{biblatex-patch}
     {Failed to patch cite bibmacro}}
% Include labelname in labelyear link
\xpatchbibmacro{cite}
  {\printnames{labelname}%
   \setunit{\printdelim{nameyeardelim}}%
   \usebibmacro{cite:labeldate+extradate}}
  {\printtext[bibhyperref]{%
     \DeclareFieldAlias{bibhyperref}{default}%
     \printnames{labelname}%
     \setunit{\printdelim{nameyeardelim}}%
     \usebibmacro{cite:labeldate+extradate}}}
  {}
  {\PackageWarning{biblatex-patch}
     {Failed to patch cite bibmacro}}
% Access hyperref's citation link start/end commands
\makeatletter
\protected\def\blx@imc@biblinkstart{%
  @ifnextchar[%]
    {\blx@biblinkstart}
    {\blx@biblinkstart[\abx@field@entrykey]}}
\def\blx@biblinkstart[#1]{%
  \blx@sfsave\hyper@natlinkstart{\the\c@refsection @#1}\blx@sfrest}
\protected\def\blx@imc@biblinkend{%
  \blx@sfsave\hyper@natlinkend\blx@sfrest}
\blx@regimcs{\biblinkstart \biblinkend}
\makeatother
\newbool{cbx:link}
% Include parentheses around labelyear in \textcite only in
% single citations without pre- and postnotes
\def\iflinkparens{%
  \ifboolexpr{ test {\ifnumequal{\value{multicitetotal}}{0}} and
               test {\ifnumequal{\value{citetotal}}{1}} and
               test {\iffieldundef{prenote}} and
               test {\iffieldundef{postnote}} }}
\xpatchbibmacro{textcite}
  {\printnames{labelname}}
  {\iflinkparens
     {\DeclareFieldAlias{bibhyperref}{default}%
      \global\booltrue{cbx:link}\biblinkstart%
      \printnames{labelname}}
     {\printtext[bibhyperref]{\printnames{labelname}}}}
  {}
  {\PackageWarning{biblatex-patch}
     {Failed to patch textcite bibmacro}}
\xpatchbibmacro{textcite}
  {\usebibmacro{cite:label}}
  {\iflinkparens
     {\DeclareFieldAlias{bibhyperref}{default}%
      \global\booltrue{cbx:link}\biblinkstart%
      \usebibmacro{cite:label}}
     {\usebibmacro{cite:label}}}
  {}
  {\PackageWarning{biblatex-patch}
     {Failed to patch textcite bibmacro}}
\xpretobibmacro{textcite:postnote}
  {\ifbool{cbx:link}
     {\ifbool{cbx:parens}
        {\bibcloseparen\global\boolfalse{cbx:parens}}
        {}%
      \biblinkend\global\boolfalse{cbx:link}}
     {}}
  {}
  {\PackageWarning{biblatex-patch}
     {Failed to patch textcite:postnote bibmacro}}
\renewcommand{\baselinestretch}{1.2}
\setlength{\parskip}{\smallskipamount}
\setlength{\parindent}{0pt}
\addbibresource{biblatex-examples.bib}
\begin{document}
\null\vfill
\textbf{Single citations}
Filler text \parencite{aristotle:poetics}.
Filler text \parencite{kant:ku}. Filler text \parencite{cms}. \
Filler text \parencite[See][23]{aristotle:poetics}.
Filler text \parencite[1--10]{kant:ku}. \
\textcite{knuth:ct} and \textcite{knuth:ct:a}.
\textcite{knuth:ct:b} and \textcite{knuth:ct:c}. \
\textcite{aristotle:poetics} and \textcite{kant:ku} and \textcite{cms}. \
\textcite[e.g.][]{aristotle:poetics} and \textcite[10]{kant:ku}. \
Filler text.\footcite[23]{aristotle:poetics} Filler text.\footcite[1--10]{aristotle:rhetoric}
Filler text.\footnote{\smartcite[10--15]{companion}}
\textbf{Unqualified citation lists}
\textcite{knuth:ct,knuth:ct:a,knuth:ct:b,knuth:ct:c} showed that... \
\textcite[e.g.][10--15]{aristotle:poetics,aristotle:rhetoric,cms} showed that...\
Filler text \parencite[See][for example]{aristotle:poetics,aristotle:rhetoric,cms}. \
Filler text \parencite[etc.]{knuth:ct,knuth:ct:a,knuth:ct:b,knuth:ct:c}.
\textbf{Qualified citation lists}
\textcites{aristotle:poetics}{aristotle:rhetoric} showed that...
\textcites(See)(){aristotle:poetics}[cf.][]{aristotle:rhetoric}. \
\textcites(See)()[e.g.][15]{aristotle:poetics}[cf.][10]{aristotle:rhetoric} \
\parencites(See)()[10--15]{aristotle:poetics}[cf.][10]{aristotle:rhetoric} \
\parencites{knuth:ct,knuth:ct:a}[10--11]{knuth:ct:b,knuth:ct:c}
\textbf{Mix of qualified and unqualified citation lists}
\textcites(See)()[e.g.][]{aristotle:poetics}[10]{bertram,companion} \
\textcites[e.g.][]{aristotle:poetics,aristotle:rhetoric}[10]{companion} \
\textcites[10]{aristotle:poetics}{aristotle:rhetoric}[cf.][]{bertram} \
\textcites[15]{aristotle:poetics}[cf.][10]{bertram,companion}
\printbibliography
\chapter*{Appendix}
\end{document}

Here is the output you should get with biblatex 2.6 or earlier. The patches also work with later releases, where \textcite and friends incorporate the and string into the final citation delimiter.

Answer 2

I would prefer another solution:

\makeatletter
%Works without the last bracket ;-)
\let\abx@macro@citeOrig\abx@macro@cite
\renewbibmacro{cite}{%
   \bibhyperref{%
   \let\bibhyperref\relax\relax%
   \abx@macro@citeOrig%
   }%
}
\let\abx@macro@textciteOrig\abx@macro@textcite
\renewbibmacro{textcite}{%
   \bibhyperref{%
   \let\bibhyperref\relax\relax%
   \abx@macro@textciteOrig%
   }%
}%
\makeatother

You can use it for every cite-command.

\documentclass{article} 
\usepackage[utf8]{inputenc} 
\usepackage[style=authoryear-comp,backend=biber,hyperref]{biblatex} 
\usepackage[colorlinks]{hyperref} 
\bibliography{biblatex-examples} 

\makeatletter
%Works without the last bracket ;-)
\let\abx@macro@citeOrig\abx@macro@cite
\renewbibmacro{cite}{%
   \bibhyperref{%
   \let\bibhyperref\relax\relax%
   \abx@macro@citeOrig%
   }%
}
\let\abx@macro@textciteOrig\abx@macro@textcite
\renewbibmacro{textcite}{%
   \bibhyperref{%
   \let\bibhyperref\relax\relax%
   \abx@macro@textciteOrig%
   }%
}%
\makeatother


\begin{document} 
A reference to \parencite{kastenholz,sigfridsson} and~\cite{sigfridsson}. 
\printbibliography 
\end{document}

EDIT:

I change the code of the example above.

\makeatletter
   \patchcmd{\blx@citeprint}%
           {\blx@loopcode}%
           {\blx@imc@bibhyperlink{#1}‌​‌​{\blx@loopcode}}%
           {}{}
\makeatother

The problem: The last bracket isn't part of the link.