On the Lua side, you'll have to pass strings so your example works, as
tables like those in setuphead({somehead}, {somesettings}) are actual Lua
tables and follow Lua, not TeX, rules (see e.g. Lua reference in
https://www.lua.org/manual/5.4/ or, better, CLD manual in
http://www.pragma-ade.nl/general/manuals/cld-mkiv.pdf):


\starttext

\startluacode

--First example

for m = 1, 3 do

context.setuphead({'chapter'}, {before='hello'})

context.startchapter({title="I'm a chapter!"})

for i = 1, 3 do

context.input("knuth")

end

context.stopchapter()

end


--Second example

--We'll pass some strings to TeX

local nice = "ConTeXt is love, ConTeXt is life"

local somehead = 'chapter'

local sometext = 'vallejo-trilce-es'


context.setuphead({somehead}, {before=nice})

context.startchapter({title=somehead})

context.input(sometext)

context.stopchapter()

\stopluacode

\stoptext


I hope examples help.

Regards,

Jairo :)



El lun., 2 de nov. de 2020 a la(s) 21:09, Sylvain Hubert (
champignoom@gmail.com) escribió:

> Dear List,
>
> I'm trying to mirror the context command
>   `\setuphead[chapter][before=hello]`
> into lua with delayed typesetting of 'hello', but
>   `\ctxlua{context.setuphead({'chapter'},
> {before=context.delayed'hello'})}`
> does not have any effect. Could anyone help me on this? Thanks!
>
> Best,
> Sylvain
>
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to
> the Wiki!
>
> maillist : ntg-context@ntg.nl /
> http://www.ntg.nl/mailman/listinfo/ntg-context
> webpage  : http://www.pragma-ade.nl / http://context.aanhet.net
> archive  : https://bitbucket.org/phg/context-mirror/commits/
> wiki     : http://contextgarden.net
>
> ___________________________________________________________________________________
>