From 3958887efe48e84af5564b2d95406a6bbc8d9d4a Mon Sep 17 00:00:00 2001
From: Andrey Astafyev <dev@246060.ru>
Date: Thu, 25 Apr 2019 16:21:16 +0300
Subject: [PATCH] plantuml filter

---
 filters/pandoc_plantuml_filter.py | 71 +++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100755 filters/pandoc_plantuml_filter.py

diff --git a/filters/pandoc_plantuml_filter.py b/filters/pandoc_plantuml_filter.py
new file mode 100755
index 0000000..e6b0755
--- /dev/null
+++ b/filters/pandoc_plantuml_filter.py
@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+
+from __future__ import print_function
+
+"""
+Pandoc filter to process code blocks with class "plantuml" into
+plant-generated images.
+Needs `plantuml.jar` from http://plantuml.com/.
+"""
+
+import os
+import sys
+import subprocess
+import re
+import hashlib
+
+from pandocfilters import toJSONFilter, Para, Image, RawBlock
+from pandocfilters import get_filename4code, get_caption, get_extension
+
+PLANTUML_BIN = os.environ.get('PLANTUML_BIN', 'plantuml')
+
+pattern = re.compile('%{(.*)\}$')
+
+def plantuml(key, value, format_, meta):
+
+    if key == 'Header':
+        if 'tikz'in (str(meta)):
+            os.environ["PLANTUML_LATEX_EXPORT"] = 'latex'
+
+    if key == 'CodeBlock':
+        if os.getenv("DEBUG", "f").lower() in ("1", "true"):
+            print("plantuml", key, value, format_, meta)
+
+        [[ident, classes, keyvals], code] = value
+
+        if "plantuml" in classes:
+            caption, typef, keyvals = get_caption(keyvals)
+
+            if "PLANTUML_LATEX_EXPORT" in os.environ:
+                latex_img_format = "latex"
+            else:
+                latex_img_format = "eps"
+
+            os.makedirs("images", exist_ok=True)
+            filename = "images/" + hashlib.sha1(code.encode(sys.getfilesystemencoding())).hexdigest()
+            filetype = get_extension(format_, "png", html="svg", latex=latex_img_format, beamer=latex_img_format)
+
+            src = filename + '.uml'
+            dest = filename + '.' + filetype
+
+            if not os.path.isfile(dest):
+                txt = code.encode(sys.getfilesystemencoding())
+                if not txt.startswith(b"@start"):
+                    txt = b"@startuml\n" + txt + b"\n@enduml\n"
+                with open(src, "wb") as f:
+                    f.write(txt)
+                subprocess.check_call(PLANTUML_BIN.split() + ["-t" + filetype, src])
+                sys.stderr.write('Created image ' + dest + '\n')
+            if (filetype == "latex") and (latex_img_format == 'latex'):
+                latex = open(dest).read()
+                return RawBlock('latex', latex.split("\\begin{document}")[-1].split("\\end{document}")[0])
+            else:
+                return Para([Image([ident, [], keyvals], caption, [dest, typef])])
+
+
+def main():
+    toJSONFilter(plantuml)
+
+
+if __name__ == "__main__":
+    main()