Basic infrastructure for fixing bug 827036.

* Use zope.events to signal when a mailing list has been created or deleted.
* Register a handler for the ListDeletedEvent which cleans up member
  subscriptions.
* Relax the criteria for find_members(), both internally and in the REST API,
  so that the subscriber is not required.  E.g. you can now find all members
  of a mailing list.

8 files changed, 176 insertions, 39 deletions

diff --git a/src/mailman/app/docs/subscriptions.rst b/src/mailman/app/docs/subscriptions.rst
index 378dd0a40..8291132ce 100644
--- a/src/mailman/app/docs/subscriptions.rst
+++ b/src/mailman/app/docs/subscriptions.rst
@@ -79,7 +79,7 @@ If you know the member id for a specific member, you can get that member.
     <Member: anne <anne@example.com> on test@example.com as MemberRole.owner>
 
 If you know the member's address, you can find all their memberships, based on
-specific search criteria.  At a minimum, you need the member's email address.
+specific search criteria.
 ::
 
     >>> mlist2 = create_list('foo@example.com')
@@ -121,6 +121,17 @@ Memberships can also be searched for by user id.
      <Member: anne <anne@example.com> on test@example.com
               as MemberRole.moderator>]
 
+You can find all the memberships for a specific mailing list.
+
+    >>> service.find_members(fqdn_listname='test@example.com')
+    [<Member: anne <anne@example.com> on test@example.com
+              as MemberRole.member>,
+     <Member: anne <anne@example.com> on test@example.com as MemberRole.owner>,
+     <Member: anne <anne@example.com> on test@example.com
+              as MemberRole.moderator>,
+     <Member: Bart Person <bart@example.com> on test@example.com
+              as MemberRole.member>]
+
 You can find all the memberships for an address on a specific mailing list.
 
     >>> service.find_members('anne@example.com', 'test@example.com')
diff --git a/src/mailman/app/events.py b/src/mailman/app/events.py
new file mode 100644
index 000000000..4beac8212
--- /dev/null
+++ b/src/mailman/app/events.py
@@ -0,0 +1,38 @@
+# Copyright (C) 2011 by the Free Software Foundation, Inc.
+#
+# This file is part of GNU Mailman.
+#
+# GNU Mailman is free software: you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option)
+# any later version.
+#
+# GNU Mailman is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# GNU Mailman.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Global events."""
+
+from __future__ import absolute_import, unicode_literals
+
+__metaclass__ = type
+__all__ = [
+    'initialize',
+    ]
+
+
+from zope import event
+
+from mailman.app.subscriptions import handle_ListDeleteEvent
+
+
+
+def initialize():
+    """Initialize global event subscribers."""
+    event.subscribers.extend([
+        handle_ListDeleteEvent,
+        ])
diff --git a/src/mailman/app/subscriptions.py b/src/mailman/app/subscriptions.py
index ab8c3d53c..57609a006 100644
--- a/src/mailman/app/subscriptions.py
+++ b/src/mailman/app/subscriptions.py
@@ -22,6 +22,7 @@ from __future__ import absolute_import, unicode_literals
 __metaclass__ = type
 __all__ = [
     'SubscriptionService',
+    'handle_ListDeleteEvent',
     ]
 
 
@@ -34,7 +35,8 @@ from mailman.app.membership import add_member, delete_member
 from mailman.config import config
 from mailman.core.constants import system_preferences
 from mailman.interfaces.address import InvalidEmailAddressError
-from mailman.interfaces.listmanager import IListManager, NoSuchListError
+from mailman.interfaces.listmanager import (
+    IListManager, ListDeletedEvent, NoSuchListError)
 from mailman.interfaces.member import DeliveryMode
 from mailman.interfaces.subscriptions import (
     ISubscriptionService, MissingUserError)
@@ -93,43 +95,43 @@ class SubscriptionService:
             assert members.count() == 1, 'Too many matching members'
             return members[0]
 
-    def find_members(self, subscriber, fqdn_listname=None, role=None):
+    def find_members(self, subscriber=None, fqdn_listname=None, role=None):
         """See `ISubscriptionService`."""
         # If `subscriber` is a user id, then we'll search for all addresses
         # which are controlled by the user, otherwise we'll just search for
         # the given address.
         user_manager = getUtility(IUserManager)
-        query = None
-        if isinstance(subscriber, basestring):
-            # subscriber is an email address.
-            address = user_manager.get_address(subscriber)
-            user = user_manager.get_user(subscriber)
-            # This probably could be made more efficient.
-            if address is None or user is None:
-                return []
-            or_clause = Or(Member.address_id == address.id,
-                           Member.user_id == user.id)
-        else:
-            # subscriber is a user id.
-            user = user_manager.get_user_by_id(unicode(subscriber))
-            address_ids = list(address.id for address in user.addresses
-                               if address.id is not None)
-            if len(address_ids) == 0 or user is None:
-                return []
-            or_clause = Or(Member.user_id == user.id,
-                           Member.address_id.is_in(address_ids))
-        # The rest is the same, based on the given criteria.
-        if fqdn_listname is None and role is None:
-            query = or_clause
-        elif fqdn_listname is None:
-            query = And(Member.role == role, or_clause)
-        elif role is None:
-            query = And(Member.mailing_list == fqdn_listname, or_clause)
-        else:
-            query = And(Member.mailing_list == fqdn_listname,
-                        Member.role == role,
-                        or_clause)
-        results = config.db.store.find(Member, query)
+        if subscriber is None and fqdn_listname is None and role is None:
+            return []
+        # Querying for the subscriber is the most complicated part, because
+        # the parameter can either be an email address or a user id.
+        query = []
+        if subscriber is not None:
+            if isinstance(subscriber, basestring):
+                # subscriber is an email address.
+                address = user_manager.get_address(subscriber)
+                user = user_manager.get_user(subscriber)
+                # This probably could be made more efficient.
+                if address is None or user is None:
+                    return []
+                query.append(Or(Member.address_id == address.id,
+                                Member.user_id == user.id))
+            else:
+                # subscriber is a user id.
+                user = user_manager.get_user_by_id(unicode(subscriber))
+                address_ids = list(address.id for address in user.addresses
+                                   if address.id is not None)
+                if len(address_ids) == 0 or user is None:
+                    return []
+                query.append(Or(Member.user_id == user.id,
+                                Member.address_id.is_in(address_ids)))
+        # Calculate the rest of the query expression, which will get And'd
+        # with the Or clause above (if there is one).
+        if fqdn_listname is not None:
+            query.append(Member.mailing_list == fqdn_listname)
+        if role is not None:
+            query.append(Member.role == role)
+        results = config.db.store.find(Member, And(*query))
         return sorted(results, key=_membership_sort_key)
 
     def __iter__(self):
@@ -177,3 +179,16 @@ class SubscriptionService:
             raise NoSuchListError(fqdn_listname)
         # XXX for now, no notification or user acknowledgement.
         delete_member(mlist, address, False, False)
+
+
+
+def handle_ListDeleteEvent(event):
+    """Delete a mailing list's members when the list is deleted."""
+
+    if not isinstance(event, ListDeletedEvent):
+        return
+    # Find all the members still associated with the mailing list.
+    members = getUtility(ISubscriptionService).find_members(
+        fqdn_listname=event.fqdn_listname)
+    for member in members:
+        member.unsubscribe()
diff --git a/src/mailman/core/initialize.py b/src/mailman/core/initialize.py
index 148d1a150..bf0f8b542 100644
--- a/src/mailman/core/initialize.py
+++ b/src/mailman/core/initialize.py
@@ -147,6 +147,7 @@ def initialize_2(debug=False, propagate_logs=None):
     # Initialize the rules and chains.  Do the imports here so as to avoid
     # circular imports.
     from mailman.app.commands import initialize as initialize_commands
+    from mailman.app.events import initialize as initialize_events
     from mailman.core.chains import initialize as initialize_chains
     from mailman.core.pipelines import initialize as initialize_pipelines
     from mailman.core.rules import initialize as initialize_rules
@@ -155,6 +156,7 @@ def initialize_2(debug=False, propagate_logs=None):
     initialize_chains()
     initialize_pipelines()
     initialize_commands()
+    initialize_events()
 
 
 def initialize_3():
diff --git a/src/mailman/interfaces/subscriptions.py b/src/mailman/interfaces/subscriptions.py
index c6bc47d5d..aa2e318f0 100644
--- a/src/mailman/interfaces/subscriptions.py
+++ b/src/mailman/interfaces/subscriptions.py
@@ -68,7 +68,7 @@ class ISubscriptionService(Interface):
         :rtype: `IMember`
         """
 
-    def find_members(subscriber, fqdn_listname=None, role=None):
+    def find_members(subscriber=None, fqdn_listname=None, role=None):
         """Search for and return a specific member.
 
         The members are sorted first by fully-qualified mailing list name,
diff --git a/src/mailman/model/tests/test_member.py b/src/mailman/model/tests/test_member.py
index 7906d8983..0fc18cfa6 100644
--- a/src/mailman/model/tests/test_member.py
+++ b/src/mailman/model/tests/test_member.py
@@ -28,7 +28,9 @@ __all__ = [
 import unittest
 
 from mailman.app.lifecycle import create_list
+from mailman.interfaces.listmanager import IListManager
 from mailman.interfaces.member import MembershipError
+from mailman.interfaces.subscriptions import ISubscriptionService
 from mailman.interfaces.user import UnverifiedAddressError
 from mailman.interfaces.usermanager import IUserManager
 from mailman.testing.layers import ConfigLayer
@@ -98,7 +100,38 @@ class TestMember(unittest.TestCase):
 
 
 
+class TestMembership(unittest.TestCase):
+    layer = ConfigLayer
+
+    def setUp(self):
+        self._ant = create_list('ant@example.com')
+        self._bee = create_list('bee@example.com')
+        self._usermanager = getUtility(IUserManager)
+
+    def test_members_are_deleted_when_mailing_list_is_deleted(self):
+        # When a mailing list with members is deleted, all the Member records
+        # are also deleted.
+        anne = self._usermanager.create_address('anne@example.com')
+        bart = self._usermanager.create_address('bart@example.com')
+        anne_ant = self._ant.subscribe(anne)
+        anne_bee = self._bee.subscribe(anne)
+        bart_ant = self._ant.subscribe(bart)
+        anne_ant_id = anne_ant.member_id
+        anne_bee_id = anne_bee.member_id
+        bart_ant_id = bart_ant.member_id
+        getUtility(IListManager).delete(self._ant)
+        service = getUtility(ISubscriptionService)
+        # We deleted the ant@example.com mailing list.  Anne's and Bart's
+        # membership in this list should now be removed, but Anne's membership
+        # in bee@example.com should still exist.
+        self.assertEqual(service.get_member(anne_ant_id), None)
+        self.assertEqual(service.get_member(bart_ant_id), None)
+        self.assertEqual(service.get_member(anne_bee_id), anne_bee)
+
+
+
 def test_suite():
     suite = unittest.TestSuite()
     suite.addTest(unittest.makeSuite(TestMember))
+    suite.addTest(unittest.makeSuite(TestMembership))
     return suite
diff --git a/src/mailman/rest/docs/membership.rst b/src/mailman/rest/docs/membership.rst
index 426b80acf..bed4f425d 100644
--- a/src/mailman/rest/docs/membership.rst
+++ b/src/mailman/rest/docs/membership.rst
@@ -308,6 +308,43 @@ example, we can search for all the memberships of a particular address.
     start: 0
     total_size: 2
 
+Or, we can find all the memberships for a particular mailing list.
+
+    >>> dump_json('http://localhost:9001/3.0/members/find', {
+    ...           'fqdn_listname': 'bee@example.com',
+    ...           })
+    entry 0:
+        address: aperson@example.com
+        fqdn_listname: bee@example.com
+        http_etag: ...
+        role: member
+        self_link: http://localhost:9001/3.0/members/3
+        user: http://localhost:9001/3.0/users/3
+    entry 1:
+        address: bperson@example.com
+        fqdn_listname: bee@example.com
+        http_etag: ...
+        role: member
+        self_link: http://localhost:9001/3.0/members/1
+        user: http://localhost:9001/3.0/users/1
+    entry 2:
+        address: cperson@example.com
+        fqdn_listname: bee@example.com
+        http_etag: ...
+        role: member
+        self_link: http://localhost:9001/3.0/members/2
+        user: http://localhost:9001/3.0/users/2
+    entry 3:
+        address: cperson@example.com
+        fqdn_listname: bee@example.com
+        http_etag: ...
+        role: owner
+        self_link: http://localhost:9001/3.0/members/7
+        user: http://localhost:9001/3.0/users/2
+    http_etag: "66836d0f23bed36fa9e0cda1e5dec7e5b0797743"
+    start: 0
+    total_size: 4
+
 Or, we can find all the memberships for an address on a particular mailing
 list.
 
diff --git a/src/mailman/rest/members.py b/src/mailman/rest/members.py
index 0a4b99470..047c375bb 100644
--- a/src/mailman/rest/members.py
+++ b/src/mailman/rest/members.py
@@ -193,10 +193,11 @@ class FindMembers(_MemberBase):
     def find(self, request):
         """Find a member"""
         service = getUtility(ISubscriptionService)
-        validator = Validator(fqdn_listname=unicode,
-                              subscriber=unicode,
-                              role=enum_validator(MemberRole),
-                              _optional=('fqdn_listname', 'role'))
+        validator = Validator(
+            fqdn_listname=unicode,
+            subscriber=unicode,
+            role=enum_validator(MemberRole),
+            _optional=('fqdn_listname', 'subscriber', 'role'))
         members = service.find_members(**validator(request))
         # We can't just return the _FoundMembers instance, because
         # CollectionMixins have only a GET method, which is incompatible with