Added graphviz.py example script.

1 files changed, 47 insertions, 0 deletions

diff --git a/scripts/graphviz.py b/scripts/graphviz.py
new file mode 100755
index 000000000..ec31578ab
--- /dev/null
+++ b/scripts/graphviz.py
@@ -0,0 +1,47 @@
+#!/usr/bin/env python
+
+"""Pandoc filter to process code blocks with class "graphviz" into
+graphviz-generated images.
+"""
+
+import pygraphviz
+import hashlib
+import os
+import sys
+from pandoc import toJSONFilter
+
+def sha1(x):
+  return hashlib.sha1(x).hexdigest()
+
+imagedir = "graphviz-images"
+files = []
+
+def graphviz(key, value, format):
+  if key == 'CodeBlock':
+    [[ident,classes,keyvals], code] = value
+    caption = "caption"
+    if "graphviz" in classes:
+      G = pygraphviz.AGraph(string = code)
+      G.layout()
+      filename = sha1(code)
+      if format == "html":
+        filetype = "png"
+      elif format == "latex":
+        filetype = "pdf"
+      else:
+        filetype = "png"
+      alt = [{'Str': caption}]
+      src = imagedir + '/' + filename + '.' + filetype
+      if not src in files:
+        try:
+          os.mkdir(imagedir)
+          sys.stderr.write('Created directory ' + imagedir)
+        except OSError:
+          pass
+        G.draw(src)
+        sys.stderr.write('Created image ' + src)
+      tit = ""
+      return {'Para': [{'Image': [alt, [src,tit]]}]}
+
+if __name__ == "__main__":
+  toJSONFilter(graphviz)