Wrapping existing bibmacro

Question

I'm searching for a way to make biblatex only print URLs if there's no DOI specified (in my case the DOIs lead to a links in the refs anyhow, making the URL sort of redundant).

I came up with this (but it seems to cause an endless loop as compilation doesn't finish...):

\renewbibmacro*{url+urldate}{%
  \iffieldundef{doi}
    {\usebibmacro{url+urldate}}
    {}%
}

it seems saving the macro with \let doesn't work due to the +...

any idea how to do this properly?

M(N)WEB:

\documentclass{article}
\usepackage[style=authoryear-comp]{biblatex}
\usepackage{hyperref}

%\renewbibmacro*{url+urldate}{%
%  \iffieldundef{doi}
%    {\usebibmacro{url+urldate}}
%    {}%
%

\addbibresource{\jobname.bib}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{key,
  author = {Author, A.},
  year = {2001},
  title = {Title},
  publisher = {Publisher},
  archivePrefix = {arXiv},
  arxivId = {1607.07249},
  doi = {10.1007/978-3-319-49004-5_22},
  eprint = {1607.07249},
  url = {http://link.springer.com/10.1007/978-3-319-49004-5_22},
}
\end{filecontents}

\begin{document}
\nocite{*}
\printbibliography
\end{document}

Welcome to TeX.SX! You can have a look at our starter guide to familiarize yourself further with our format. In particular, please add a complete minimal working example with bibliography (MWEB)! — CarLaTeX, Apr 24 '17 at 15:17
Note that your URL field should read url = {http://link.springer.com/10.1007/978-3-319-49004-5_22}. There is no need to escape special characters in URLs, indeed it has adverse effects to do so. — moewe, Apr 24 '17 at 16:32
comes form mendeley bibtex export like that... fixed nevertheless... — Jörn Hees, Apr 25 '17 at 16:24
Well yes, some reference managers give subpar output in certain cases. If you are a stickler like me there is no way around manual double-checking. — moewe, Apr 25 '17 at 17:59

score 8 · Accepted Answer · answered Apr 24 '17 at 15:49

There is no \letbibmacro (and you might file a feature request), but it's not difficult to create one:

\documentclass{article}
\usepackage[style=authoryear-comp]{biblatex}
\usepackage{hyperref}

\newcommand{\letbibmacro}[2]{%
  \csletcs{abx@macro@#1}{abx@macro@#2}%
}

\letbibmacro{orig-url+urldate}{url+urldate}
\renewbibmacro*{url+urldate}{%
  \iffieldundef{doi}
    {\usebibmacro{orig-url+urldate}}
    {}%
}

\addbibresource{\jobname.bib}
\usepackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{key,
  author = {Author, A.},
  year = {2001},
  title = {Title},
  publisher = {Publisher},
  archivePrefix = {arXiv},
  arxivId = {1607.07249},
  doi = {10.1007/978-3-319-49004-5_22},
  eprint = {1607.07249},
  url = {http://link.springer.com/10.1007/978-3-319-49004-5{\_}22},
}
@book{key2,
  author = {Author, A.},
  year = {2001},
  title = {Title},
  publisher = {Publisher},
  archivePrefix = {arXiv},
  arxivId = {1607.07249},
  eprint = {1607.07249},
  url = {http://link.springer.com/10.1007/978-3-319-49004-5{\_}22},
}
\end{filecontents}

\begin{document}
\nocite{*}
\printbibliography
\end{document}

\letbibmacro was added to biblatex in version 3.8 (released 2017-11-04), see https://github.com/plk/biblatex/pull/640/ and https://github.com/plk/biblatex/commit/e9d32e072d076bd907e4f4071d38d57fd3630a41 — moewe, Oct 29 '18 at 11:40

score 5 · Answer 2 · answered Apr 24 '17 at 16:38

5

You have already gotten great answers to the question you asked, so I thought I'd add two solutions for the problem that you want to solve.

You can use

\DeclareSourcemap{
  \maps[datatype=bibtex]{
    \map{
      \step[fieldsource=doi, final]
      \step[fieldset=url, null]
      \step[fieldset=urldate, null]
    }
  }
}

or

\AtEveryBibitem{%
  \iffieldundef{doi}
    {}
    {\clearfield{url}\clearfield{urlyear}}%
}

to not print the URL if a DOI is present.

answered Apr 24 '17 at 16:38

moewe

175,683

this is indeed nice to know and upvoted, but as i was in general after properly wrapping, the accept goes to egreg – Jörn Hees Apr 25 '17 at 16:28

samcarter_is_at_topanswers.xyz · Answer 3 · 2017-04-24T16:07:05.490

To conditionally print the url, you could wrap it in \iffieldundef{doi}{}{}

\documentclass{article}
\usepackage[style=authoryear-comp]{biblatex}
\usepackage{hyperref}

% print url if no doi
\renewbibmacro*{doi+eprint+url}{%
  \printfield{doi}
  \newunit\newblock
  \iftoggle{bbx:eprint}{
      \usebibmacro{eprint}
  }{}%
  \newunit\newblock
  \iffieldundef{doi}{
      \usebibmacro{url+urldate}}
      {}
}
\addbibresource{\jobname.bib}
\usepackage{filecontents}
\begin{filecontents*}{\jobname.bib}
@book{key,
  author = {Author, A.},
  year = {2001},
  title = {Title},
  publisher = {Publisher},
  archivePrefix = {arXiv},
  arxivId = {1607.07249},
  doi = {10.1007/978-3-319-49004-5_22},
  eprint = {1607.07249},
  url = {http://link.springer.com/10.1007/978-3-319-49004-5{\_}22},
}

@book{keyx,
  author = {Author, A.},
  year = {2001},
  title = {Title},
  publisher = {Publisher},
  archivePrefix = {arXiv},
  arxivId = {1607.07249},
  url = {http://link.springer.com/10.1007/978-3-319-49004-5{\_}22},
}
\end{filecontents*}

\begin{document}
\nocite{*}
\printbibliography
\end{document}

hmm, my idea was not to create a code copy of the standards that might get outdated, upvote anyhow ;) — Jörn Hees, Apr 24 '17 at 15:15

Wrapping existing bibmacro

M(N)WEB:

3 Answers3

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