Pandoc: Convert DOT to TikZ

README.md

Pandoc: Convert DOT to TikZ

Using Pandoc's Lua AST manipulation, we can convert DOT blocks into TikZ during compile time, and then have LaTeX generate a graph rendering.

Running

An example command that uses this filter

pandoc --pdf-engine=xelatex --lua-filter ./dot2tex.lua -o out.pdf in.md

Dependencies

You must have dot2text

Usage

Simply include the DOT in a dot attributed code block

```dot
digraph graphname {
    a -> b -> c;
    b -> d;
}
```

And the LaTeX output will include the following picture:

dot2tex.lua

--- Converts DOT block to TikZ
-- @author Michael Miller
-- Scans for dot attributed code blocks and converts them into representative
--  tikz using the dot2tex tool.
-- see https://pandoc.org/lua-filters.html for documentation on pandoc filters
-- see https://dot2tex.readthedocs.io/en/latest/ for documentation on doc2tex
-- @return TikZ represenation of DOT
function CodeBlock(block)
    if block.classes[1] == "dot" then
        -- Write dot data to temporary file location.
        unique = tostring(block):gsub("table: ", "")
        filename = "/tmp/dot2tex_"..unique..".dot"
        fp = io.open(filename, "w")
        dot = block.text
        fp:write(dot)
        fp:close()

        -- Run dot2tex over temporary dot file.
        cmd = "dot2tex --preproc "..filename.." | dot2tex --figonly --codeonly"
        fp = io.popen(cmd)
        tikz = "\\begin{center}\\begin{tikzpicture}[>=latex',line join=bevel,]"..fp:read("*a").."\\end{tikzpicture}\\end{center}"
        fp:close()

        -- Remove temporary file.
        os.remove(filename)

        return pandoc.RawBlock("latex", tikz)
    end
end