Can I use Lua to fetch web resources during compilation?

[zachcp]

Description

Q: I have in mind a Quarto extension that allows users to declare JS dependencies within a code block and then let LUA download those resources to a consistent folder for loading during runtime. Are there any examples of doing this, and are there any reasons why this is a terrible idea?

Context: I want to offer a lightweight pyodide env that can load local WHL files that are provided or downloaded during compilation.

[mcanouil]

Are there any examples of doing this,

No examples that I am aware of. You can try to browse the extensions listing:

Note that there is an existing pyodide Quarto extension.

Edit: It seems the Pyodide Quarto extension is downloading things, take a look at https://github.com/coatless-quarto/pyodide/blob/main/_extensions/pyodide/qpyodide.lua#L139-L142

Technically speaking, nothing is blocking you from using any custom YAML key that would contain whatever and use that in your Lua filter (meta) to do whatever you want with it.

[cscheid]

Relatedly - can a filter depend on another filter?

Not cleanly. Filter extensions declare filters, and filters are used in documents. But extensions do not declare the order in which the filters execute. By design, that's left to the user documents. You can document a recommended order, of course, but you can't enforce it: we are aware of the limitation, but couldn't arrive at a design that we deemed to be simple and effective enough.

[zachcp]

Also -looks like Quarto live has almost exactly what I need: https://r-wasm.github.io/quarto-live/getting_started/packages.html#custom-repositories

[zachcp]

@cscheid are filters executed in the order they are listed in the YAML? E.G. if I wanted to provide a filter to add some niceties on top of quarto-live - would I need only add my filter first in the list?

[zachcp]

FYI: quarto-live for the win. https://zachcp.github.io/qlive-mvspec/about.html

Now I am looking to see if there is away to pass the same format: html options in to format:live-html to get side-by-side.

[cscheid]

would I need only add my filter first in the list?

last. The filters are executed in the order they're specified. You can experiment with this yourself by writing

---
format: html
filters:
  - my_filter_1.lua
  - my_filter_2.lua
---

And then writing some test filters in each file to examine the behavior.