Using koma variables for zugferd data

[t-b]

(I'm pretty sure this is a standard latex question but I'm not really good at this.)

I would like to use komascript variables for the zugferd data entries to avoid duplication of values.

Now from glancing at the package code, and https://tex.stackexchange.com/a/532873/77589, I managed to cargo cult something like

\newkomavar{companyname-plain}
\setkomavar{companyname-plain}{ACME Inc.}

\newkomavar{fromname}
\setkomavar{fromname}{My Name}

\SetZUGFeRDData*{
    document-type = commercial-invoice,
    seller/name = {\csname scr@companyname-plain@var\endcsname\space(\csname scr@fromname@var\endcsname)},
}
    payment-terms={Zahlbar innerhalb von \csname scr@payment-terms-duration@var\endcsname},
}

together. But it's hideous to use and look at.

I've tried the obvious

\def\rawkomavalue#1{\csname scr@#1@var\endcsname}

to wrap the calls but that does not work. Is there a more elegant way?

[TeXhackse]

Generally this works. Though you could juse use \UseName{…} instead of \csname …\endcsname nowerdays or the expl3 c-type.

I guess the issue you face comes from the timing. You seem to set that variable before the komavar is set.

So you have to ensure to pass the value before you do the expansion, which you do at the moment of \SetZUGFeRDData* by using the starred version. You could use a hook or something like \AtBeginLetter to do that later.

[t-b]

Thanks, using \UseName did the trick.

I'm now using

\newkomavar{postcode}
\setkomavar{postcode}{01234}

\newcommand{\expandkomavar}[1]{\UseName{scr@#1@var}}

\SetZUGFeRDData*{
    document-type = commercial-invoice,
    seller/postcode = \expandkomavar{postcode},
}

which works.