How to write a filter that behave differently launched with Quarto or with Pandoc?

[pagiraud]

Description

I’ve written a Lua filter that I would like to be able to use with Pandoc and with Quarto. It works with both but, because the preamble (it’s a filter for latex) is not exactly the same when generating from Pandoc or Quarto, the resulting PDF doesn’t look the same. Is there a way I can detect if my filter is launched with Quarto or with Pandoc, so my filter can adapt accordingly to compensate the difference?

[cderv]

Good question !

One way to do it is that if your filter is ran within Quarto context, the Quarto Lua API will be defined
https://prerelease.quarto.org/docs/extensions/lua-api.html#quarto-lua-api

So you could test for quarto object, or quarto.version for example. If it exists, then you are in Quarto context.

Example

if quarto and quarto.version then
  quarto.log.output("Running in Quarto: " .. tostring(quarto.version))
else
  print("Not running in Quarto")
end

return {}

[pagiraud]

Hey, thanks! I just got the same idea. ;)

[pagiraud]

If there is a proper way to do that, I’m interested but for now I’ll go with:

if quarto ~= nil then
  print("Quarto")
else
  print("Pandoc")
end

[cderv]

This is a good way IMO.