[Zope3-checkins] CVS: Zope3/lib/python/Zope/App/index - subscribers.py:1.1 subscription_control.pt:1.1

Thu, 5 Dec 2002 08:47:43 -0500

Update of /cvs-repository/Zope3/lib/python/Zope/App/index
In directory cvs.zope.org:/tmp/cvs-serv1306/lib/python/Zope/App/index

Added Files:
	subscribers.py subscription_control.pt 
Log Message:
added small component that registers objects with the objecthub as they are added.

=== Added File Zope3/lib/python/Zope/App/index/subscribers.py ===
##############################################################################
#
# Copyright (c) 2002 Zope Corporation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""XXX short summary goes here.

XXX longer description goes here.

$Id: subscribers.py,v 1.1 2002/12/05 13:47:43 stevea Exp $
"""
__metaclass__ = type

from Interface import Interface
from Zope.Event.ISubscriber import ISubscriber
from Zope.Event.IObjectEvent import IObjectAddedEvent
from Zope.ContextWrapper import ContextMethod
from Persistence import Persistent
from Zope.ComponentArchitecture import getService

class ISubscriptionControl(Interface):
    def subscribe():
        """Subscribe to the prevailing object hub service."""

    def unsubscribe():
        """Unsubscribe from the object hub service."""

    def isSubscribed():
        """Return whether we are currently subscribed."""

class Registration(Persistent):

    __implements__ = ISubscriptionControl, ISubscriber

    def notify(wrapped_self, event):
        """An event occured. Perhaps register this object with the hub."""
        getService(wrapped_self, "ObjectHub").register(event.object)
    notify = ContextMethod(notify)

    currentlySubscribed = False # Default subscription state

    def subscribe(wrapped_self):
        if wrapped_self.currentlySubscribed:
            raise RuntimeError, "already subscribed; please unsubscribe first"
        channel = wrapped_self._getChannel(None)
        channel.subscribe(wrapped_self, IObjectAddedEvent)
        wrapped_self.currentlySubscribed = True
    subscribe = ContextMethod(subscribe)

    def unsubscribe(wrapped_self):
        if not wrapped_self.currentlySubscribed:
            raise RuntimeError, "not subscribed; please subscribe first"
        channel = wrapped_self._getChannel(None)
        channel.unsubscribe(wrapped_self, IObjectAddedEvent)
        wrapped_self.currentlySubscribed = False
    unsubscribe = ContextMethod(unsubscribe)

    def isSubscribed(self):
        return self.currentlySubscribed

    def _getChannel(wrapped_self, channel):
        if channel is None:
            channel = getService(wrapped_self, "ObjectHub")
        return channel
    _getChannel = ContextMethod(_getChannel)

=== Added File Zope3/lib/python/Zope/App/index/subscription_control.pt ===
<html>

  <body>

    <h1>Subscription control</h1>

    <span tal:condition="request/callSubscribe|nothing" tal:omit-tag="">
        <span tal:define="dummy context/subscribe" tal:omit-tag=""/>
    </span>
    <span tal:condition="request/callUnsubscribe|nothing" tal:omit-tag="">
        <span tal:define="dummy context/unsubscribe" tal:omit-tag=""/>
    </span>

    <form method="POST">
       <span tal:condition="context/isSubscribed" tal:omit-tag="">
           Subscription state: ON
           <input type="submit" value="Unsubscribe" name="callUnsubscribe" />
       </span>
       <span tal:condition="not:context/isSubscribed" tal:omit-tag="">
           Subscription state: OFF
           <input type="submit" value="Subscribe" name="callSubscribe" />
       </span>
    </form>

  </body>

</html>