About activitystream

activitystream is a Pluggable application for TurboGears2 for create a simple activity stream.

The activity stream is intended to be used as base layer for a notification system

Currently this pluggable works only with ming fell free to submit a pull request with sqlalchemy support

Installing

activitystream can be installed both from pypi or from github:

pip install activitystream

should just work for most of the users

Plugging activitystream

In your application config/app_cfg.py import plug:

from tgext.pluggable import plug

Then at the end of the file call plug with activitystream:

plug(base_config, 'activitystream')

ActionManager

When you want to create an activity you should do something like:

from activitystream import ActionManager
am = ActionManager()

activity = am.create(
    actor=model.User.query.find().all()[0],
    verb='created',
    target=model.Post.query.find().all()[0],
    recipients=model.User.query.find().all()[1:3],
)

Then you may want to notify the activity to the recipients. It's up to you to choose how to dispatch them.

Fields Explanation

• actor: reference to who is creating the activity
• verb: a string describing the action itself, for example 'created' or 'updated'
• action_obj: reference to ... I don't know
• target: reference to the subject of the activity
• timestamp: datetime of the creation of the activity
• description: string with a description of the activity
• extra: string that you can use for example to store a json with extra informations
• recipients: list of references to who is expected to receive a notification from this activity. references can be of different entities.

Not Seen (counter of unread notifications)

Add in your recipient model (probably your User model):

from datetime import datetime
last_activity_seen = FieldProperty(s.DateTime, if_missing=datetime.utcnow())

then you can get the latest 10 notifications of a recipient with:

recipient = model.User.query.find().all()[1]
actions = am.get_by_recipient(recipient).limit(10).all()
# and if you want a counter of unread notifications call
count = am.count_not_seen_by_recipient(recipient)
# you can check if the recipient have seen a notification with
not_seen = actions[0].timestamp > recipient.last_activity_seen
# don't forget to update your recipient when him reads his notifications
recipient.last_activity_seen = datetime.utcnow()

Exposed Controllers

if you don't like your urls to start with activitystream just plug with a new app_id

• /activitystream/ajax_update_last_seen_of_a_recipient: call this through ajax with _type and _id of the recipient to update last_activity_seen. should return a json with the last_activity_seen before the update
• /activitystream/see: updates last_activity_seen of the logged in user and redirects to the given target_link

Notifications Rendering

This is up to you. I suggest to use tg.render_template with tg_cache

adding in myproject.lib.helpers:

from activitystream import am
from tg import render_template
def notification_cache(n):
    return {
        'cache_key': n._id,  # this is really important
        'cache_expire': 604800,  # a week
        'cache_type': 'memory',
    }

and in the template where you want your notifications to being displayed:

<py:for each="n in h.am.get_by_recipient(request.identity['user']).limit(10)">
  <li>${h.render_template(
    {'n': n, 'tg_cache': h.notification_cache(n)},
    'kajiki',
    'myproject.templates.notification'
  )}<hr/></li>
</py:for>

meanwhile your myproject.templates.notification may look like:

<a href="${h.plug_url('activitystream', '/see', params={'target_link': n.target_link})}">
  <img src="${n.actor.avatar_url}"/>
  <div class="content">
    <b>${n.actor.display_name}</b> ${_(n.verb)} <i>${n.target}</i>
    <div>${n.timestamp_since}</div>
  </div>
</a>

if your notification needs to be rendered differently based on the recipient then you have to use another caching strategy