Initial

pandoc/codeblock-filter.lua

@@ -0,0 +1,35 @@
+-- insprired from https://github.com/pandoc/lua-filters/blob/5686d96/diagram-generator/diagram-generator.lua
+
+local dotPath = os.getenv("DOT") or "dot"
+
+local filetype = "svg"
+local mimetype = "image/svg+xml"
+
+local function graphviz(code, filetype)
+    return pandoc.pipe(dotPath, {"-T" .. filetype}, code)
+end
+
+function CodeBlock(block)
+    local converters = {
+        graphviz = graphviz,
+    }
+
+    local img_converter = converters[block.classes[1]]
+    if not img_converter then
+      return nil
+    end
+
+    local success, img = pcall(img_converter, block.text, filetype)
+
+    if not success then
+        io.stderr:write(tostring(img))
+        io.stderr:write('\n')
+        error 'Image conversion failed. Aborting.'
+    end
+
+    return pandoc.RawBlock('html', img)
+end
+
+return {
+    {CodeBlock = CodeBlock},
+}