Custom bibliography problem

[tracyrage]

Hi everyone! I'm writing a document in Romanian and I have to make some changes in the default bibliography style. Instead of in-text et al must be si colab. Anyways, I managed to solve this problem while writing in plain latex (Overleaf). However, I cannot manage to do it in RMarkdown.

Here's the YAML header:

---
title: "xxx"
documentclass: report
output: 
  bookdown::pdf_book:
    latex_engine: xelatex
    number_sections: true
    citation_package: biblatex
    includes: 
      in_header: preamble.tex
biblatexoptions: [backend=biber, style=authoryear]
bibliography: references.bib
papersize: letter
lang: ro-RO
indent: true
header-includes:
- \usepackage{times}
- \usepackage{indentfirst}
- \usepackage{fancyhdr}
- \pagestyle{fancy}
---

And here is the preamble.tex

\NewBibliographyString{
  langromanian,
  summerN,winterN,autumnN,springN,
  summerS,winterS,autumnS,springS,
  Q1,Q2,Q3,Q4,S1,S2,
}
\DefineBibliographyStrings{romanian}{andothers = {și colab.,}}
\DeclareFieldFormat{pages}{#1}

Additionally, I have aromanian.ibx in the directory

And I get this error:

! Undefined control sequence.
l.70 \NewBibliographyString
                           {

Any ideas?

[gsapijaszko]

I would start checking .texfile after kniting, especially, if biblatex package is included prior to \DefineBibliographyStrings command.

From my own experience, there is a quite silly way, how the .tex file is created.

Regards,
Grzegorz

[cderv]

It seems @gsapijaszko could have found the root of the issue. rmarkdown is using Pandoc and its template to generate the PDF. The template in Pandoc will do

\usepackage{biblatex}

after the part about the header includes. See

jgm/pandoc/blob/d9ec95e7abc71a642dd8e53b92f2bd3ae1609f10/data/templates/default.latex#L379-L402

Header include part line 379 and biblatex loading 399.

So that is probably why.

It seems an issue with Pandoc. You would need a custom template to allow this : defining new entries in preamble.

[gsapijaszko]

@cderv

It seems @gsapijaszko could have found the root of the issue.

Years working with latex . I personally found R *down very useful, however the way how the .tex file is build (and what's inside before \begin{document} is a bit strange.

Regards,
Grzegorz

[cderv]

@gsapijaszko

I personally found R *down very useful, however the way how the .tex file is build (and what's inside before \begin{document} is a bit strange.

We welcome any feedback on that! Most of the content come from the Pandoc's template that we use.
We'll be happy to take into account any feedback for *down ecosystem or even for Pandoc directly.
Please feel free to open an issue in one of the repo or contact me directly.

Feedback from experienced users is really important to improve the tools !