handler.py

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#! /usr/bin/python
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#* Author: Eitan Marder-Eppstein
#***********************************************************
import rospy
import rosweb
import threading
import Image
import cStringIO

from continuous_ops_msgs.msg import Tasks, Task

#_lock = threading.Lock()
_image_cache = {}

def task_cb(data):
    for task in data.tasks:
        print task.task_id
        print task.image_file
        im = Image.open(task.image_file)
        buf = cStringIO.StringIO()
        im.save(buf, format='JPEG')
        jpeg = buf.getvalue()
        _image_cache[task.task_id] = jpeg

def config_plugin(context):
    global task_sub
    task_sub = rospy.Subscriber("task_manager/available_tasks", Tasks, task_cb)
    context.register_handler('/task', task_server_handler)

def send_image(self, jpeg, cache_control='max-age=3600'):
    try:
        self.send_response(200)
        self.send_header('Cache-Control', cache_control)
        self.send_header('Content-Type', 'image/jpeg')
        self.send_header('Content-Length', str(len(jpeg)))
        self.end_headers()
        self.wfile.write(jpeg)
    except:
        pass


def task_server_handler(self, path, qdict):
    print "task"
    print path
    print qdict
    if path == '/task/image':
        print qdict['id'][0]
        jpeg = _image_cache[qdict['id'][0]]
        send_image(self, jpeg)
    return True