Garcon - Context Example

flow.py

import boto.swf.layer2 as swf
 
from garcon import activity
from garcon import runner
from garcon import task
 
domain = 'dev'
name = 'context_example'
create = activity.create(domain, name)
 
 
@task.decorate()
def bootstrap():
    # The bootstrap is just here to provide more information 
    # in the context which we can use later on. It's for the
    # purpose of this demo.
    return dict(user_id='<user id>', email='<email id>')
 
 
@task.decorate()
def process_payment_for_user(user_id):
    # Process the payment for a specific user
    return dict(payment_id='<payment id>')
    
 
@task.decorate()
def send_email_to_user(user_id, email, payment_id):
    # Send some information to the user about the payment id
    print('Email sent to {email} ({user_id}) about {payment_id}'.format(
        user_id=user_id,
        payment_id=payment_id,
        email=email))
    return
    
    
initialize = create(
    name='initialize',
    tasks=runner.Sync(
        bootstrap.fill()))
 
process = create(
    name='process_payment',
    requires=[initialize],
    tasks=runner.Sync(
        # The bootstrap returns `user_id` in the context. The value will be
        # captured from the context then sent to the activity.
        process_payment_for_user.fill(user_id='user_id')))
 
finish_payment = create(
    name='finish_payment',
    requires=[process],
    tasks=runner.Sync(send_email_to_user.fill(
        # Same as above except this time, we're trying to get more information
        # from the context.
        user_id='user_id',
        payment_id='payment_id', 
        email='email')))