Can I change the authors with -M via command line ?

[KaiWaldrant]

Description

I was wondering if you can change the author metadata like the title and subtitle metadata via the command line option -M.

We are creating dynamic html reports with quarto but the authors should change depending on who has setup the analysis. So I was trying to set the author field dynamically with -M author:"Kai Waldrant" like I did with the title and subtitle -M title:"Test title" -M subtitle:"Test subtitle" but only the titles changes not the author. Is there a way to do this ?

I have been searching the discussion part but haven't found an answer.

[mcanouil]

I am not sure you can as the author field is not a scalar, see https://quarto.org/docs/journals/authors.html#author-schema.

Pinging @dragonstyle in case I am mistaken.

[rgaiacs]

--variable and --metadata do not work based on the metadata reported by Quarto's log.

--metadata-file works based on the metadata reported by Quarto's log but this does NOT show in the final output.

Minimal Working Example

mwe.qmd:

---
title: MWE
author: Alice
---

Foo

metadata.yaml:

author: Eve

quarto render mwe.qmd --to html --metadata-file=metadata.yaml prints

pandoc 
  to: html
  output-file: mwe.html
  standalone: true
  section-divs: true
  html-math-method: mathjax
  wrap: none
  default-image-extension: png
  
metadata
  document-css: false
  link-citations: true
  date-format: long
  lang: en
  author: Eve
  title: MWE
  
Output created: mwe.html

grep -i alice mwe.html prints

<meta name="author" content="Alice">
             <p>Alice </p>

[KaiWaldrant]

Yeah so that's what I am experiencing. I find it weird that you can change the author field in that way but the output still has the previous value. What is the point of this then ?

[cderv]

This could be related to this issue:

• metadata override through CLI flags is inconsitent #6123

--metadata values will be processed through isQuartoMetadata() function, and add to metadata to be used by Quarto process. Otherwise they will be considered Pandoc only metadata.

author is among the value that are not correctly identified as isQuartoMetadata(). It is why using -M does not work here.
Though you wouldn't be able to pass only a string for author and not another object using -M

--metadata-file is only considered as Pandoc only metadata. No quarto metadata (like citation or date-format) can be passed to be processed by Quarto

Authors field needs to be treated by Quarto in a specific way, and I don't think this works with --metadata-files currently.

But also --metadata-files in Pandoc does not override YAML header field value (https://pandoc.org/MANUAL.html#option--metadata-file)

Metadata values specified inside the document, or by using -M, overwrite values specified with this option.

So it can't be use even with Pandoc to change the value. This means we either

• have a report problem in the Quarto log as author: Eve should not be shown
• or we do change the Pandoc behavior and override and this is really metadata override through CLI flags is inconsitent #6123 problem.

cc @dragonstyle in case you have more context. We should definitely make all that clearer.

[KaiWaldrant]

I changed the discussion to a feature request.

[cderv]

We are creating dynamic html reports with quarto but the authors should change depending on who has setup the analysis. So I was trying to set the author field dynamically with -M author:"Kai Waldrant" like I did with the title and subtitle -M title:"Test title" -M subtitle:"Test subtitle" but only the titles changes not the author. Is there a way to do this ?

Have you considered making your file use an external file metadata ?
https://quarto.org/docs/projects/quarto-projects.html#shared-metadata

This would be a hardcoded file name in your .qmd but the content would change based on who is the author ?

For a project with a dir like that

Quarto project
--| _quarto.yml
--| article_dir
   --| doc.qmd
   --| _medadata.author1.yml
   --| _medadata.author2.yml

You could do a pre render script or any other one (like makefile) and do

cp article_dir/_metadata.author1.yml article_dir/_metadata.yml
quarto render doc.qmd

This examples leverage the directory shared meta (https://quarto.org/docs/projects/quarto-projects.html#directory-metadata) but you could also leverage the metadata-file YAML option: https://quarto.org/docs/projects/quarto-projects.html#metadata-includes
with the same concept.

---
title: MWE
metadata-file: authors.yml
format: html
---

Foo

You can then adapt authors.yml content depending on who renders.

It seems this works even if --metadata-files don't because it is not processed the same... 🤔 Related to #6260 (reply in thread) and #6123

You can't do

quarto render doc.qmd -M metadata-file:author-1.yml

because of #6123

see my previous comment #6260 (reply in thread)

Definitely something we need to improve here

[KaiWaldrant]

i'll check this out

[KaiWaldrant]

It does work. Thank you for the workaround.

Also checked if it would add an author to the output if the author field was already defined. It falls back to the method of the --metadata-file saga. Looks like this is all a bit underdeveloped (which I understand, no accusations here :) ) We're all here to test and report

---
author:
  - name: author 1
  - name: author 2
metadata-file: authors.yaml
---

The authors defined in authors.yaml is not in the output html but is added in the pandoc metadata

[cderv]

if it would add an author to the output if the author field was already defined. It falls back to the method of the --metadata-file saga.

I believe this is the Pandoc default behavior here. As I said in other post above, --metadata-files in Pandoc does not override YAML header field value (pandoc.org/MANUAL.html#option--metadata-file)

When using metadata-file, it requires to have no YAML field in the document that would override it.

I am not sure we would want to change this Pandoc behavior 🤔 Or if we do we would need to really warn and document it.

[KaiWaldrant]

Either way the documentation needs some clarifying