How to write TeX with a Lua function taking a string parameter

Question

I have this piece of code working :

Tex file :

\documentclass{article}
\usepackage{tcolorbox,graphicx,tikz}
\directlua{dofile("placeTextNode.lua")}
\newcommand*{\textNode}{%
    \directlua{tex.print(textNode())}%
}
\usepackage[paperwidth=120pt, paperheight=120pt, margin=10pt]{geometry}
\begin{document}
    \begin{tcolorbox}[boxsep=0pt, left=0pt, right=0pt, top=0pt, bottom=0pt, sharpish corners, opacityframe=0, opacityback=0, boxrule=0pt]
        \begin{tikzpicture}[x=1pt, y=1pt]
            \draw[line width=0mm, white] (0,0) -- (100,0) -- (100,100) -- (0, 100);
            \textNode
        \end{tikzpicture}
    \end{tcolorbox}
\end{document}

placeTextNode.lua file:

function textNode()
    return "\\draw[xshift=50, yshift=50] node[draw, anchor=north west]{AAA};"
end

Now, if I want to take a string and print it in place of AAA, all the various attempts I did in the past 3/4 days have failed.

I took inspiration from :

• Passing arguments from TeX to a Lua function

What I'd like to do is to write instead of \textNode

\textNode{"some 
multiline 
text"}

and have my text displayed in my tikz node.

One of my multiple attempts, even before trying to go multiline, was the following :

TeX file :

\documentclass{article}
\usepackage{tcolorbox,graphicx,tikz}
\directlua{dofile("placeTextNode.lua")}
\newcommand*{\textNode[1]}{%
    \directlua{tex.print(textNode(\luastring{#1}))}%
}
\usepackage[paperwidth=120pt, paperheight=120pt, margin=10pt]{geometry}
\begin{document}
    \begin{tcolorbox}[boxsep=0pt, left=0pt, right=0pt, top=0pt, bottom=0pt, sharpish corners, opacityframe=0, opacityback=0, boxrule=0pt]
        \begin{tikzpicture}[x=1pt, y=1pt]
            \draw[line width=0mm, white] (0,0) -- (100,0) -- (100,100) -- (0, 100);
            \textNode{"AAA"}
        \end{tikzpicture}
    \end{tcolorbox}
\end{document}

placeTextNode.lua :

function textNode(t)
    return "\\draw[xshift=50, yshift=50] node[draw, anchor=north west]{" .. t .. "};"
end

I get the following error :

/home/new command.tex:14: Undefined control sequence.
\\textNode ...tlua {tex.print(textNode(\luastring 
                                                  {#1}))}
l.14             \textNode{
                         "AAA"}
placeTextNode.lua:2: attempt to concatenate a table value (local 't')
stack traceback:
    placeTextNode.lua:2: in function 'textNode'
    [\directlua]:1: in main chunk.
\\textNode ...ex.print(textNode(\luastring {#1}))}
l.14             \textNode{
                         "AAA"}

Answer 1

You need to specify text width for text to be multiline.

\documentclass{article}
\usepackage{luacode}
\begin{luacode}
function textNode(s)
    return string.format("\draw[xshift=50, yshift=50] node[draw, anchor=north west, text width=1cm, text centered]{%s};", s)
end
\end{luacode}
\usepackage{tcolorbox,graphicx,tikz}
\newcommand*{\textNode}[1]{%
    \directlua{tex.print(textNode("\luaescapestring{#1}"))}%
}
\usepackage[paperwidth=120pt, paperheight=120pt, margin=10pt]{geometry}
\begin{document}
    \begin{tcolorbox}[boxsep=0pt, left=0pt, right=0pt, top=0pt, bottom=0pt, sharpish corners, opacityframe=0, opacityback=0, boxrule=0pt]
        \begin{tikzpicture}[x=1pt, y=1pt]
            \draw[line width=0mm, white] (0,0) -- (100,0) -- (100,100) -- (0, 100);
            \textNode{abc\ def}
        \end{tikzpicture}
    \end{tcolorbox}
\end{document}