# Digesting

Mailman crafts and sends digests by a separate digest runner process. This starts by a number of messages being posted to the mailing list.

    >>> mlist = create_list('test@example.com')
    >>> mlist.digest_size_threshold = 0.6
    >>> mlist.volume = 1
    >>> mlist.next_digest_number = 1
    >>> mlist.send_welcome_message = False

    >>> from string import Template
    >>> process = config.handlers['to-digest'].process

    >>> def fill_digest():
    ...     size = 0
    ...     for i in range(1, 5):
    ...         text = Template("""\
    ... From: aperson@example.com
    ... To: xtest@example.com
    ... Subject: Test message $i
    ... List-Post: <test@example.com>
    ...
    ... Here is message $i
    ... """).substitute(i=i)
    ...         msg = message_from_string(text)
    ...         process(mlist, msg, {})
    ...         size += len(text)
    ...         if size >= mlist.digest_size_threshold * 1024:
    ...             break

    >>> fill_digest()

The runner gets kicked off when a marker message gets dropped into the digest queue. The message metadata points to the mailbox file containing the messages to put in the digest.

    >>> digestq = config.switchboards['digest']
    >>> len(digestq.files)
    1

    >>> from mailman.testing.helpers import get_queue_messages
    >>> entry = get_queue_messages('digest')[0]

The marker message is empty.

    >>> print(entry.msg.as_string())

But the message metadata has a reference to the digest file.

    >>> dump_msgdata(entry.msgdata)
    _parsemsg    : False
    digest_number: 1
    digest_path  : .../lists/test.example.com/digest.1.1.mmdf
    listid       : test.example.com
    version      : 3
    volume       : 1

There are 4 messages in the digest.

    >>> from mailman.utilities.mailbox import Mailbox
    >>> sum(1 for item in Mailbox(entry.msgdata['digest_path']))
    4

When the runner runs, it processes the digest mailbox, crafting both the plain text (RFC 1153) digest and the MIME digest.

    >>> from mailman.runners.digest import DigestRunner
    >>> from mailman.testing.helpers import make_testable_runner
    >>> runner = make_testable_runner(DigestRunner)
    >>> runner.run()

If there are no members receiving digests, none are sent.

    >>> messages = get_queue_messages('virgin')
    >>> len(messages)
    0

Once some users are subscribed and receiving digests, the digest runner places both digests into the virgin queue for final delivery.

    >>> from mailman.testing.helpers import subscribe
    >>> from mailman.interfaces.member import DeliveryMode

    >>> anne = subscribe(mlist, 'Anne')
    >>> anne.preferences.delivery_mode = DeliveryMode.mime_digests
    >>> bart = subscribe(mlist, 'Bart')
    >>> bart.preferences.delivery_mode = DeliveryMode.plaintext_digests

    >>> fill_digest()
    >>> runner.run()
    >>> messages = get_queue_messages('virgin')
    >>> len(messages)
    2

Anne and Bart unsubscribe from the mailing list.

    >>> anne.unsubscribe()
    >>> bart.unsubscribe()

The MIME digest is a multipart, and the RFC 1153 digest is the other one.

    >>> def mime_rfc1153(messages):
    ...     if messages[0].msg.is_multipart():
    ...         return messages[0], messages[1]
    ...     return messages[1], messages[0]

    >>> mime, rfc1153 = mime_rfc1153(messages)

The MIME digest has lots of good stuff, all contained in the multipart.

    >>> print(mime.msg.as_string())
    Content-Type: multipart/mixed; boundary="===============...=="
    MIME-Version: 1.0
    From: test-request@example.com
    Subject: Test Digest, Vol 1, Issue 2
    To: test@example.com
    Reply-To: test@example.com
    Date: ...
    Message-ID: ...
    <BLANKLINE>
    --===============...==
    Content-Type: text/plain; charset="us-ascii"
    MIME-Version: 1.0
    Content-Transfer-Encoding: 7bit
    Content-Description: Test Digest, Vol 1, Issue 2
    <BLANKLINE>
    Send Test mailing list submissions to
        test@example.com
    <BLANKLINE>
    To subscribe or unsubscribe via email, send a message with subject or
    body 'help' to
        test-request@example.com
    <BLANKLINE>
    You can reach the person managing the list at
        test-owner@example.com
    <BLANKLINE>
    When replying, please edit your Subject line so it is more specific
    than "Re: Contents of Test digest..."
    --===============...==
    Content-Type: text/plain; charset="us-ascii"
    MIME-Version: 1.0
    Content-Transfer-Encoding: 7bit
    Content-Description: Today's Topics (4 messages)
    <BLANKLINE>
    Today's Topics:
    <BLANKLINE>
       1. Test message 1 (aperson@example.com)
       2. Test message 2 (aperson@example.com)
       3. Test message 3 (aperson@example.com)
       4. Test message 4 (aperson@example.com)
    <BLANKLINE>
    --===============...==
    Content-Type: multipart/digest; boundary="===============...=="
    MIME-Version: 1.0
    <BLANKLINE>
    --===============...==
    Content-Type: message/rfc822
    MIME-Version: 1.0
    <BLANKLINE>
    From: aperson@example.com
    To: xtest@example.com
    Subject: Test message 1
    List-Post: <test@example.com>
    <BLANKLINE>
    Here is message 1
    <BLANKLINE>
    --===============...==
    Content-Type: message/rfc822
    MIME-Version: 1.0
    <BLANKLINE>
    From: aperson@example.com
    To: xtest@example.com
    Subject: Test message 2
    List-Post: <test@example.com>
    <BLANKLINE>
    Here is message 2
    <BLANKLINE>
    --===============...==
    Content-Type: message/rfc822
    MIME-Version: 1.0
    <BLANKLINE>
    From: aperson@example.com
    To: xtest@example.com
    Subject: Test message 3
    List-Post: <test@example.com>
    <BLANKLINE>
    Here is message 3
    <BLANKLINE>
    --===============...==
    Content-Type: message/rfc822
    MIME-Version: 1.0
    <BLANKLINE>
    From: aperson@example.com
    To: xtest@example.com
    Subject: Test message 4
    List-Post: <test@example.com>
    <BLANKLINE>
    Here is message 4
    <BLANKLINE>
    --===============...==--
    <BLANKLINE>
    --===============...==
    Content-Type: text/plain; charset="us-ascii"
    MIME-Version: 1.0
    Content-Transfer-Encoding: 7bit
    Content-Description: Digest Footer
    <BLANKLINE>
    _______________________________________________
    Test mailing list -- test@example.com
    To unsubscribe send an email to test-leave@example.com
    <BLANKLINE>
    --===============...==--
    <BLANKLINE>

The RFC 1153 contains the digest in a single plain text message.

    >>> print(rfc1153.msg.as_string())
    From: test-request@example.com
    Subject: Test Digest, Vol 1, Issue 2
    To: test@example.com
    Reply-To: test@example.com
    Date: ...
    Message-ID: ...
    MIME-Version: 1.0
    Content-Type: text/plain; charset="us-ascii"
    Content-Transfer-Encoding: 7bit
    <BLANKLINE>
    Send Test mailing list submissions to
        test@example.com
    <BLANKLINE>
    To subscribe or unsubscribe via email, send a message with subject or
    body 'help' to
        test-request@example.com
    <BLANKLINE>
    You can reach the person managing the list at
        test-owner@example.com
    <BLANKLINE>
    When replying, please edit your Subject line so it is more specific
    than "Re: Contents of Test digest..."
    <BLANKLINE>
    Today's Topics:
    <BLANKLINE>
       1. Test message 1 (aperson@example.com)
       2. Test message 2 (aperson@example.com)
       3. Test message 3 (aperson@example.com)
       4. Test message 4 (aperson@example.com)
    <BLANKLINE>
    <BLANKLINE>
    ----------------------------------------------------------------------
    <BLANKLINE>
    From: aperson@example.com
    Subject: Test message 1
    To: xtest@example.com
    <BLANKLINE>
    Here is message 1
    <BLANKLINE>
    ------------------------------
    <BLANKLINE>
    From: aperson@example.com
    Subject: Test message 2
    To: xtest@example.com
    <BLANKLINE>
    Here is message 2
    <BLANKLINE>
    ------------------------------
    <BLANKLINE>
    From: aperson@example.com
    Subject: Test message 3
    To: xtest@example.com
    <BLANKLINE>
    Here is message 3
    <BLANKLINE>
    ------------------------------
    <BLANKLINE>
    From: aperson@example.com
    Subject: Test message 4
    To: xtest@example.com
    <BLANKLINE>
    Here is message 4
    <BLANKLINE>
    ------------------------------
    <BLANKLINE>
    Subject: Digest Footer
    <BLANKLINE>
    _______________________________________________
    Test mailing list -- test@example.com
    To unsubscribe send an email to test-leave@example.com
    <BLANKLINE>
    <BLANKLINE>
    ------------------------------
    <BLANKLINE>
    End of Test Digest, Vol 1, Issue 2
    **********************************
    <BLANKLINE>

## Digest delivery

A mailing list’s members can choose to receive normal delivery, plain text digests, or MIME digests.

    >>> len(get_queue_messages('virgin'))
    0

    >>> from mailman.interfaces.usermanager import IUserManager
    >>> from zope.component import getUtility
    >>> user_manager = getUtility(IUserManager)

    >>> from mailman.interfaces.member import DeliveryMode, MemberRole
    >>> def subscribe(email, mode):
    ...     address = user_manager.create_address(email)
    ...     member = mlist.subscribe(address, MemberRole.member)
    ...     member.preferences.delivery_mode = mode
    ...     return member

Two regular delivery members subscribe to the mailing list.

    >>> member_1 = subscribe('uperson@example.com', DeliveryMode.regular)
    >>> member_2 = subscribe('vperson@example.com', DeliveryMode.regular)

Two MIME digest members subscribe to the mailing list.

    >>> member_3 = subscribe('wperson@example.com', DeliveryMode.mime_digests)
    >>> member_4 = subscribe('xperson@example.com', DeliveryMode.mime_digests)

One RFC 1153 digest member subscribes to the mailing list.

    >>> member_5 = subscribe(
    ...     'yperson@example.com', DeliveryMode.plaintext_digests)
    >>> member_6 = subscribe(
    ...     'zperson@example.com', DeliveryMode.plaintext_digests)

When a digest gets sent, the appropriate recipient list is chosen.

    >>> mlist.preferred_language = 'en'
    >>> mlist.digest_size_threshold = 0.5
    >>> fill_digest()
    >>> runner.run()

The digests are sitting in the virgin queue. One of them is the MIME digest and the other is the RFC 1153 digest.

    >>> messages = get_queue_messages('virgin')
    >>> len(messages)
    2

    >>> mime, rfc1153 = mime_rfc1153(messages)

Only wperson and xperson get the MIME digests.

    >>> sorted(mime.msgdata['recipients'])
    ['wperson@example.com', 'xperson@example.com']

Only yperson and zperson get the RFC 1153 digests.

    >>> sorted(rfc1153.msgdata['recipients'])
    ['yperson@example.com', 'zperson@example.com']

Now uperson decides that they would like to start receiving digests too.

    >>> member_1.preferences.delivery_mode = DeliveryMode.mime_digests
    >>> fill_digest()
    >>> runner.run()

    >>> messages = get_queue_messages('virgin')
    >>> len(messages)
    2

    >>> mime, rfc1153 = mime_rfc1153(messages)
    >>> sorted(mime.msgdata['recipients'])
    ['uperson@example.com', 'wperson@example.com', 'xperson@example.com']

    >>> sorted(rfc1153.msgdata['recipients'])
    ['yperson@example.com', 'zperson@example.com']

At this point, both uperson and wperson decide that they’d rather receive regular deliveries instead of digests. uperson would like to get any last digest that may be sent so that she doesn’t miss anything. wperson does care as much and does not want to receive one last digest.

    >>> mlist.send_one_last_digest_to(
    ...     member_1.address, member_1.preferences.delivery_mode)

    >>> member_1.preferences.delivery_mode = DeliveryMode.regular
    >>> member_3.preferences.delivery_mode = DeliveryMode.regular

    >>> fill_digest()
    >>> runner.run()

    >>> messages = get_queue_messages('virgin')
    >>> mime, rfc1153 = mime_rfc1153(messages)
    >>> sorted(mime.msgdata['recipients'])
    ['uperson@example.com', 'xperson@example.com']

    >>> sorted(rfc1153.msgdata['recipients'])
    ['yperson@example.com', 'zperson@example.com']

Since uperson has received their last digest, they will not get any more of them.

    >>> fill_digest()
    >>> runner.run()

    >>> messages = get_queue_messages('virgin')
    >>> len(messages)
    2

    >>> mime, rfc1153 = mime_rfc1153(messages)
    >>> sorted(mime.msgdata['recipients'])
    ['xperson@example.com']

    >>> sorted(rfc1153.msgdata['recipients'])
    ['yperson@example.com', 'zperson@example.com']