Pandoc Mermaid filter - html

Question

I am trying to use this pandoc filter to convert markdown to HTML.
This is the example file:
gantt
dateFormat YYYY-MM-DD
title Adding GANTT diagram functionality to mermaid
section A section
Completed task :done, des1, 2014-01-06,2014-01-08
Active task :active, des2, 2014-01-09, 3d
Future task : des3, after des2, 5d
Future task2 : des4, after des3, 5d
section Critical tasks
Completed task in the critical line :crit, done, 2014-01-06,24h
Implement parser and jison :crit, done, after des1, 2d
Create tests for parser :crit, active, 3d
Future task in critical line :crit, 5d
Create tests for renderer :2d
Add to mermaid :1d
This is the command that I am running:
pandoc file.md -f markdown -o out.html --filter=pandoc-mermaid
This is the error message:
File "D:\Anaconda3\lib\runpy.py", line 194, in _run_module_as_main
return _run_code(code, main_globals, None,
File "D:\Anaconda3\lib\runpy.py", line 87, in _run_code
exec(code, run_globals)
File "D:\Anaconda3\Scripts\pandoc-mermaid.exe\__main__.py", line 7, in <module>
File "D:\Anaconda3\lib\site-packages\pandoc_mermaid_filter.py", line 38, in main
toJSONFilter(mermaid)
File "D:\Anaconda3\lib\site-packages\pandocfilters.py", line 130, in toJSONFilter
toJSONFilters([action])
File "D:\Anaconda3\lib\site-packages\pandocfilters.py", line 164, in toJSONFilters
sys.stdout.write(applyJSONFilters(actions, source, format))
File "D:\Anaconda3\lib\site-packages\pandocfilters.py", line 195, in applyJSONFilters
altered = walk(altered, action, format, meta)
File "D:\Anaconda3\lib\site-packages\pandocfilters.py", line 123, in walk
return {k: walk(v, action, format, meta) for k, v in x.items()}
File "D:\Anaconda3\lib\site-packages\pandocfilters.py", line 123, in <dictcomp>
return {k: walk(v, action, format, meta) for k, v in x.items()}
File "D:\Anaconda3\lib\site-packages\pandocfilters.py", line 110, in walk
res = action(item['t'],
File "D:\Anaconda3\lib\site-packages\pandoc_mermaid_filter.py", line 31, in mermaid
subprocess.check_call([MERMAID_BIN, "-i", src, "-o", dest])
File "D:\Anaconda3\lib\subprocess.py", line 359, in check_call
retcode = call(*popenargs, **kwargs)
File "D:\Anaconda3\lib\subprocess.py", line 340, in call
with Popen(*popenargs, **kwargs) as p:
File "D:\Anaconda3\lib\subprocess.py", line 858, in __init__
self._execute_child(args, executable, preexec_fn, close_fds,
File "D:\Anaconda3\lib\subprocess.py", line 1311, in _execute_child
hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
FileNotFoundError: [WinError 2] El sistema no puede encontrar el archivo especificado
Error running filter pandoc-mermaid:
Filter returned error status 1
The folder where the executable is located is apparently added to path. Any ideas on how I could fix it?
Specifications:
Windows 10 Home
pandoc 2.14.0.1
Thanks

Answer 1

Not solving the problem but providing a different way to achieve the same and in case it's useful to others who arrive here:
Mermaid-cli has the feature to act as a preprocessor for Markdown.
As such, you can do the following:
mkdir build
npx -p #mermaid-js/mermaid-cli mmdc -i file.md -o build/output-svg.md
# Generates lots of output-svg-1.svg files linked from the doc
cd build
pandoc output-svg.md -o output.html
It defaults to SVG images (which generally works fine for HTML but fails when targeting PDF). It has a less well documented feature to force PNG generation.
npx -p #mermaid-js/mermaid-cli mmdc -i file.md --outputFormat=png -o build/output-png.md
# Generates lots of output-png-1.png files linked from the doc
cd build
pandoc output-png.md -o output.pdf

Answer 2

I found success with the NPM library which adds a similar Mermaid filter for Pandoc: raghur/mermaid-filter.
You should be able to do:
pandoc file.md -f markdown -o out.html --filter=mermaid-filter
IMPORTANT: On Windows, you need to specify the filter as --filter mermaid-filter.cmd instead of --filter mermaid-filter (I missed this at first and was very confused)