gistfile1.py

import pipeline
from pipeline import common


from google.appengine.ext import db
from google.appengine.api import mail
from google.appengine.api import xmpp

###### Models ######
class User(db.Model):
	
	email = db.StringProperty(default=None)
	jid = db.StringProperty(default=None)


class EmailList(db.Model):
	
	name = db.StringProperty()
	users = db.ListProperty(db.Key)


###### Pipelines ######
class EmailMessage(pipeline.Pipeline):
	
	async = True
	
	def run(self, to, subject, body):

		start_expensive_remote_task()

		task = self.get_callback_task(countdown=300, name='emailmessage-' + self.pipeline_id)
		try:
			task.add(self.queue_name)
		except (taskqueue.TombstonedTaskError, taskqueue.TaskAlreadyExistsError):
			pass
		
	def callback(self):
		
		message = mail.MailMessage(to=to)
		self.complete(message.send())
		
		
class XMPPMessage(pipeline.Pipeline):
	
	def run(self, jid, message):
		return xmpp.send_message(jid, message)
		
	
class EmailOrXMPPBlast(pipeline.Pipeline):

	def run(self, key, subject, body):
		
		e_list = EmailList.get(key)
		
		email_messages = []
		users = db.get(e_list.users)

		for user in users:
			
			if user.email != None:
				sent_message = yield EmailMessage(to=user.email, subject=subject, body=body)
				email_messages.append(sent_message)

			elif user.xmpp != None:
				yield XMPPMessage(jid=user.jid, message=body)
				
		result = yield common.Dict(users=[str(u) for u in users], results=email_messages)
		yield common.Return(result)
		
		
		
		
------------------------------------------------------------------------------------


e = EmailNewsletterBlast(some_key, 'subject', 'body')
e.start(queue_name='whatever')