Quick and dirty (seriously) hack to recursively watch for .plantuml files to generate png images in that folder.

plantumlwatchdog.py

#!/usr/bin/python

"""\
Recursively watches for .plantuml files and generates png images in that folder.

Dependencies:
    * watchdog
    * sh
    * plantuml.jar from plantuml.com

There also needs to be a 'plantumlpipe' shell script somewhere in $PATH with
the this code:

```
#! /usr/bin/env sh
java -Djava.awt.headless=true -jar plantuml.jar -pipe
```
"""

import os
import time
from watchdog.observers import Observer
from watchdog.events import FileSystemEventHandler
from sh import plantumlpipe


class PlantUmlHandler(FileSystemEventHandler):

    def on_created(self, event):
        self._check_and_create(event)

    def on_modified(self, event):
        self._check_and_create(event)

    def _check_and_create(self, event):
        filename, file_extension = os.path.splitext(event.src_path)
        if file_extension == ".plantuml":
            with open (event.src_path, "r") as myfile:
                uml=myfile.read()
            plantumlpipe(_in=uml, _out="%s.png" % filename, _bg=True)


if __name__ == "__main__":
    event_handler = PlantUmlHandler()
    observer = Observer()
    observer.schedule(event_handler, path='.', recursive=True)
    observer.start()

    try:
        while True:
            time.sleep(1)
    except KeyboardInterrupt:
        observer.stop()
    observer.join()