horae.subscription 1.0a1

Provides functionality to subscribe to an object

Introduction

horae.subscription provides generic subscription functionality for the Horae resource planning system.

Usage

Objects marked with the horae.subscription.interfaces.ISubscribeable interfaces receive the functionality of being subscribed to. Which means a viewlet is displayed rendering all subscribers and a button to subscribe and unsubscribe if an adapter implementing horae.subscription.interfaces.ISubscriber and adapting the request is available.

The subscribers of an horae.subscription.interfaces.ISubscribeable may be notified by using the horae.subscription.interfaces.ISubscription adapter. First some basic implementations are required:

import grok

from horae.subscription import interfaces

class Subscriber(object):
    grok.implements(interfaces.ISubscriber)

    def __init__(self, id, name, url=None):
        self.id = id
        self.name = name
        self.url = url

    def notify(self, message, subject):
        """ Sends the message to the subscriber
        """
        print self.name + ': (' + subject + ') ' + subject

    def available(self, context):
        """ Whether this subscriber is currently available or not
        """
        return True

class Message(object):
    grok.implements(interfaces.IMessage)

    def __init__(self, subject, message):
        self._subject = subject
        self._message = message

    def subject(self):
        """ Returns the subject of the notification to be sent
        """
        return self._subject

    def message(self, html=False):
        """ Returns the notification message to be sent
        """
        return self._message

class Subscribeable(grok.Model):
    grok.implements(interfaces.ISubscribeable)

With those implementations in place some subscriptions may be made and a message may be sent to them.

First we create a subscribeable object:

>>> subscribeable = Subscribeable()

Now we create two subscribers and subscribe them to the subscribeable:

>>> subscriber1 = Subscriber('jsmith', 'John Smith')
>>> subscriber2 = Subscriber('jdoe', 'John Doe')
>>> subscription = interfaces.ISubscription(subscribeable)
>>> subscription.subscribe(subscriber1)
>>> subscription.subscribe(subscriber2)

And send out a message:

>>> message = Message('Test subject', 'Test message')
>>> sent, failed = subscription.notify(message)
John Smith: (Test subject) Test message
John Doe: (Test subject) Test message
>>> sent
2
>>> failed
0

Unsubscription is also done using the subscription adapter:

>>> subscription.unsubscribe(subscriber2.id)
>>> sent, failed = subscription.notify(message)
John Smith: (Test subject) Test message
>>> sent
1
>>> failed
0

Dependencies

Horae

• horae.core

• horae.layout

• horae.ticketing

Third party

• grok

Changelog

1.0a1 (2012-01-16)

• Initial release