--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/web/lib/django/contrib/comments/moderation.py Wed Jan 20 00:34:04 2010 +0100
@@ -0,0 +1,354 @@
+"""
+A generic comment-moderation system which allows configuration of
+moderation options on a per-model basis.
+
+To use, do two things:
+
+1. Create or import a subclass of ``CommentModerator`` defining the
+ options you want.
+
+2. Import ``moderator`` from this module and register one or more
+ models, passing the models and the ``CommentModerator`` options
+ class you want to use.
+
+
+Example
+-------
+
+First, we define a simple model class which might represent entries in
+a weblog::
+
+ from django.db import models
+
+ class Entry(models.Model):
+ title = models.CharField(maxlength=250)
+ body = models.TextField()
+ pub_date = models.DateField()
+ enable_comments = models.BooleanField()
+
+Then we create a ``CommentModerator`` subclass specifying some
+moderation options::
+
+ from django.contrib.comments.moderation import CommentModerator, moderator
+
+ class EntryModerator(CommentModerator):
+ email_notification = True
+ enable_field = 'enable_comments'
+
+And finally register it for moderation::
+
+ moderator.register(Entry, EntryModerator)
+
+This sample class would apply two moderation steps to each new
+comment submitted on an Entry:
+
+* If the entry's ``enable_comments`` field is set to ``False``, the
+ comment will be rejected (immediately deleted).
+
+* If the comment is successfully posted, an email notification of the
+ comment will be sent to site staff.
+
+For a full list of built-in moderation options and other
+configurability, see the documentation for the ``CommentModerator``
+class.
+
+"""
+
+import datetime
+
+from django.conf import settings
+from django.core.mail import send_mail
+from django.contrib.comments import signals
+from django.db.models.base import ModelBase
+from django.template import Context, loader
+from django.contrib import comments
+from django.contrib.sites.models import Site
+
+class AlreadyModerated(Exception):
+ """
+ Raised when a model which is already registered for moderation is
+ attempting to be registered again.
+
+ """
+ pass
+
+class NotModerated(Exception):
+ """
+ Raised when a model which is not registered for moderation is
+ attempting to be unregistered.
+
+ """
+ pass
+
+class CommentModerator(object):
+ """
+ Encapsulates comment-moderation options for a given model.
+
+ This class is not designed to be used directly, since it doesn't
+ enable any of the available moderation options. Instead, subclass
+ it and override attributes to enable different options::
+
+ ``auto_close_field``
+ If this is set to the name of a ``DateField`` or
+ ``DateTimeField`` on the model for which comments are
+ being moderated, new comments for objects of that model
+ will be disallowed (immediately deleted) when a certain
+ number of days have passed after the date specified in
+ that field. Must be used in conjunction with
+ ``close_after``, which specifies the number of days past
+ which comments should be disallowed. Default value is
+ ``None``.
+
+ ``auto_moderate_field``
+ Like ``auto_close_field``, but instead of outright
+ deleting new comments when the requisite number of days
+ have elapsed, it will simply set the ``is_public`` field
+ of new comments to ``False`` before saving them. Must be
+ used in conjunction with ``moderate_after``, which
+ specifies the number of days past which comments should be
+ moderated. Default value is ``None``.
+
+ ``close_after``
+ If ``auto_close_field`` is used, this must specify the
+ number of days past the value of the field specified by
+ ``auto_close_field`` after which new comments for an
+ object should be disallowed. Default value is ``None``.
+
+ ``email_notification``
+ If ``True``, any new comment on an object of this model
+ which survives moderation will generate an email to site
+ staff. Default value is ``False``.
+
+ ``enable_field``
+ If this is set to the name of a ``BooleanField`` on the
+ model for which comments are being moderated, new comments
+ on objects of that model will be disallowed (immediately
+ deleted) whenever the value of that field is ``False`` on
+ the object the comment would be attached to. Default value
+ is ``None``.
+
+ ``moderate_after``
+ If ``auto_moderate_field`` is used, this must specify the number
+ of days past the value of the field specified by
+ ``auto_moderate_field`` after which new comments for an
+ object should be marked non-public. Default value is
+ ``None``.
+
+ Most common moderation needs can be covered by changing these
+ attributes, but further customization can be obtained by
+ subclassing and overriding the following methods. Each method will
+ be called with three arguments: ``comment``, which is the comment
+ being submitted, ``content_object``, which is the object the
+ comment will be attached to, and ``request``, which is the
+ ``HttpRequest`` in which the comment is being submitted::
+
+ ``allow``
+ Should return ``True`` if the comment should be allowed to
+ post on the content object, and ``False`` otherwise (in
+ which case the comment will be immediately deleted).
+
+ ``email``
+ If email notification of the new comment should be sent to
+ site staff or moderators, this method is responsible for
+ sending the email.
+
+ ``moderate``
+ Should return ``True`` if the comment should be moderated
+ (in which case its ``is_public`` field will be set to
+ ``False`` before saving), and ``False`` otherwise (in
+ which case the ``is_public`` field will not be changed).
+
+ Subclasses which want to introspect the model for which comments
+ are being moderated can do so through the attribute ``_model``,
+ which will be the model class.
+
+ """
+ auto_close_field = None
+ auto_moderate_field = None
+ close_after = None
+ email_notification = False
+ enable_field = None
+ moderate_after = None
+
+ def __init__(self, model):
+ self._model = model
+
+ def _get_delta(self, now, then):
+ """
+ Internal helper which will return a ``datetime.timedelta``
+ representing the time between ``now`` and ``then``. Assumes
+ ``now`` is a ``datetime.date`` or ``datetime.datetime`` later
+ than ``then``.
+
+ If ``now`` and ``then`` are not of the same type due to one of
+ them being a ``datetime.date`` and the other being a
+ ``datetime.datetime``, both will be coerced to
+ ``datetime.date`` before calculating the delta.
+
+ """
+ if now.__class__ is not then.__class__:
+ now = datetime.date(now.year, now.month, now.day)
+ then = datetime.date(then.year, then.month, then.day)
+ if now < then:
+ raise ValueError("Cannot determine moderation rules because date field is set to a value in the future")
+ return now - then
+
+ def allow(self, comment, content_object, request):
+ """
+ Determine whether a given comment is allowed to be posted on
+ a given object.
+
+ Return ``True`` if the comment should be allowed, ``False
+ otherwise.
+
+ """
+ if self.enable_field:
+ if not getattr(content_object, self.enable_field):
+ return False
+ if self.auto_close_field and self.close_after:
+ if self._get_delta(datetime.datetime.now(), getattr(content_object, self.auto_close_field)).days >= self.close_after:
+ return False
+ return True
+
+ def moderate(self, comment, content_object, request):
+ """
+ Determine whether a given comment on a given object should be
+ allowed to show up immediately, or should be marked non-public
+ and await approval.
+
+ Return ``True`` if the comment should be moderated (marked
+ non-public), ``False`` otherwise.
+
+ """
+ if self.auto_moderate_field and self.moderate_after:
+ if self._get_delta(datetime.datetime.now(), getattr(content_object, self.auto_moderate_field)).days >= self.moderate_after:
+ return True
+ return False
+
+ def email(self, comment, content_object, request):
+ """
+ Send email notification of a new comment to site staff when email
+ notifications have been requested.
+
+ """
+ if not self.email_notification:
+ return
+ recipient_list = [manager_tuple[1] for manager_tuple in settings.MANAGERS]
+ t = loader.get_template('comments/comment_notification_email.txt')
+ c = Context({ 'comment': comment,
+ 'content_object': content_object })
+ subject = '[%s] New comment posted on "%s"' % (Site.objects.get_current().name,
+ content_object)
+ message = t.render(c)
+ send_mail(subject, message, settings.DEFAULT_FROM_EMAIL, recipient_list, fail_silently=True)
+
+class Moderator(object):
+ """
+ Handles moderation of a set of models.
+
+ An instance of this class will maintain a list of one or more
+ models registered for comment moderation, and their associated
+ moderation classes, and apply moderation to all incoming comments.
+
+ To register a model, obtain an instance of ``CommentModerator``
+ (this module exports one as ``moderator``), and call its
+ ``register`` method, passing the model class and a moderation
+ class (which should be a subclass of ``CommentModerator``). Note
+ that both of these should be the actual classes, not instances of
+ the classes.
+
+ To cease moderation for a model, call the ``unregister`` method,
+ passing the model class.
+
+ For convenience, both ``register`` and ``unregister`` can also
+ accept a list of model classes in place of a single model; this
+ allows easier registration of multiple models with the same
+ ``CommentModerator`` class.
+
+ The actual moderation is applied in two phases: one prior to
+ saving a new comment, and the other immediately after saving. The
+ pre-save moderation may mark a comment as non-public or mark it to
+ be removed; the post-save moderation may delete a comment which
+ was disallowed (there is currently no way to prevent the comment
+ being saved once before removal) and, if the comment is still
+ around, will send any notification emails the comment generated.
+
+ """
+ def __init__(self):
+ self._registry = {}
+ self.connect()
+
+ def connect(self):
+ """
+ Hook up the moderation methods to pre- and post-save signals
+ from the comment models.
+
+ """
+ signals.comment_will_be_posted.connect(self.pre_save_moderation, sender=comments.get_model())
+ signals.comment_was_posted.connect(self.post_save_moderation, sender=comments.get_model())
+
+ def register(self, model_or_iterable, moderation_class):
+ """
+ Register a model or a list of models for comment moderation,
+ using a particular moderation class.
+
+ Raise ``AlreadyModerated`` if any of the models are already
+ registered.
+
+ """
+ if isinstance(model_or_iterable, ModelBase):
+ model_or_iterable = [model_or_iterable]
+ for model in model_or_iterable:
+ if model in self._registry:
+ raise AlreadyModerated("The model '%s' is already being moderated" % model._meta.module_name)
+ self._registry[model] = moderation_class(model)
+
+ def unregister(self, model_or_iterable):
+ """
+ Remove a model or a list of models from the list of models
+ whose comments will be moderated.
+
+ Raise ``NotModerated`` if any of the models are not currently
+ registered for moderation.
+
+ """
+ if isinstance(model_or_iterable, ModelBase):
+ model_or_iterable = [model_or_iterable]
+ for model in model_or_iterable:
+ if model not in self._registry:
+ raise NotModerated("The model '%s' is not currently being moderated" % model._meta.module_name)
+ del self._registry[model]
+
+ def pre_save_moderation(self, sender, comment, request, **kwargs):
+ """
+ Apply any necessary pre-save moderation steps to new
+ comments.
+
+ """
+ model = comment.content_type.model_class()
+ if model not in self._registry:
+ return
+ content_object = comment.content_object
+ moderation_class = self._registry[model]
+
+ # Comment will be disallowed outright (HTTP 403 response)
+ if not moderation_class.allow(comment, content_object, request):
+ return False
+
+ if moderation_class.moderate(comment, content_object, request):
+ comment.is_public = False
+
+ def post_save_moderation(self, sender, comment, request, **kwargs):
+ """
+ Apply any necessary post-save moderation steps to new
+ comments.
+
+ """
+ model = comment.content_type.model_class()
+ if model not in self._registry:
+ return
+ self._registry[model].email(comment, comment.content_object, request)
+
+# Import this instance in your own code to use in registering
+# your models for moderation.
+moderator = Moderator()