Synnefo

# Copyright 2013 GRNET S.A. All rights reserved.

#

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#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

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from synnefo.lib.db.xctx import TransactionContext

from astakos.im.retry_xctx import RetryTransactionHandler

from astakos.im.notifications import Notification

# USAGE

# =====

# @notification_transaction_context(notify=False)

# def a_view(args, ctx=None):

#     ...

#     if ctx:

#         ctx.mark_rollback()

#     ...

#     return http response

#

# OR (more cleanly)

#

# def a_view(args):

#     with notification_transaction_context(notify=False) as ctx:

#         ...

#         ctx.mark_rollback()

#         ...

#         return http response

def notification_transaction_context(**kwargs):

    return RetryTransactionHandler(ctx=NotificationTransactionContext, **kwargs)

class NotificationTransactionContext(TransactionContext):

    def __init__(self, notify=True, **kwargs):

        self._notifications = []

        self._messages      = []

        self._notify        = notify

        TransactionContext.__init__(self, **kwargs)

    def register(self, o):

        if isinstance(o, dict):

            msg = o.get('msg', None)

            if msg is not None:

                if isinstance(msg, basestring):

                    self.queue_message(msg)

            notif = o.get('notif', None)

            if notif is not None:

                if isinstance(notif, Notification):

                    self.queue_notification(notif)

            if o.has_key('value'):

                return o['value']

        return o

    def queue_message(self, m):

        self._messages.append(m)

    def queue_notification(self, n):

        self._notifications.append(n)

    def _send_notifications(self):

        if self._notifications is None:

            return

        # send mail

    def postprocess(self):

        if self._notify:

            self._send_notifications()

        TransactionContext.postprocess(self)