1 ==========================
2 Generic comment moderation
3 ==========================
5 .. module:: django.contrib.comments.moderation
6 :synopsis: Support for automatic comment moderation.
8 Django's bundled comments application is extremely useful on its own,
9 but the amount of comment spam circulating on the Web today
10 essentially makes it necessary to have some sort of automatic
11 moderation system in place for any application which makes use of
12 comments. To make this easier to handle in a consistent fashion,
13 ``django.contrib.comments.moderation`` provides a generic, extensible
14 comment-moderation system which can be applied to any model or set of
15 models which want to make use of Django's comment system.
21 The entire system is contained within ``django.contrib.comments.moderation``,
22 and uses a two-step process to enable moderation for any given model:
24 1. A subclass of :class:`CommentModerator`
25 is defined which specifies the moderation options the model wants to
28 2. The model is registered with the moderation system, passing in the
29 model class and the class which specifies its moderation options.
31 A simple example is the best illustration of this. Suppose we have the
32 following model, which would represent entries in a Weblog::
34 from django.db import models
36 class Entry(models.Model):
37 title = models.CharField(maxlength=250)
38 body = models.TextField()
39 pub_date = models.DateTimeField()
40 enable_comments = models.BooleanField()
42 Now, suppose that we want the following steps to be applied whenever a
43 new comment is posted on an ``Entry``:
45 1. If the ``Entry``'s ``enable_comments`` field is ``False``, the
46 comment will simply be disallowed (i.e., immediately deleted).
48 2. If the ``enable_comments`` field is ``True``, the comment will be
51 3. Once the comment is saved, an email should be sent to site staff
52 notifying them of the new comment.
54 Accomplishing this is fairly straightforward and requires very little
57 from django.contrib.comments.moderation import CommentModerator, moderator
59 class EntryModerator(CommentModerator):
60 email_notification = True
61 enable_field = 'enable_comments'
63 moderator.register(Entry, EntryModerator)
65 The :class:`CommentModerator` class pre-defines a number of useful moderation
66 options which subclasses can enable or disable as desired, and ``moderator``
67 knows how to work with them to determine whether to allow a comment, whether
68 to moderate a comment which will be allowed to post, and whether to email
69 notifications of new comments.
71 Built-in moderation options
72 ---------------------------
74 .. class:: CommentModerator
76 Most common comment-moderation needs can be handled by subclassing
77 :class:`CommentModerator` and
78 changing the values of pre-defined attributes; the full range of built-in
79 options is as follows.
81 .. attribute:: auto_close_field
83 If this is set to the name of a
84 :class:`~django.db.models.fields.DateField` or
85 :class:`~django.db.models.fields.DateTimeField` on the model for which
86 comments are being moderated, new comments for objects of that model
87 will be disallowed (immediately deleted) when a certain number of days
88 have passed after the date specified in that field. Must be
89 used in conjunction with :attr:`close_after`, which specifies the
90 number of days past which comments should be
91 disallowed. Default value is ``None``.
93 .. attribute:: auto_moderate_field
95 Like :attr:`auto_close_field`, but instead of outright deleting
96 new comments when the requisite number of days have elapsed,
97 it will simply set the ``is_public`` field of new comments to
98 ``False`` before saving them. Must be used in conjunction with
99 :attr:`moderate_after`, which specifies the number of days past
100 which comments should be moderated. Default value is ``None``.
102 .. attribute:: close_after
104 If :attr:`auto_close_field` is used, this must specify the number
105 of days past the value of the field specified by
106 :attr:`auto_close_field` after which new comments for an object
107 should be disallowed. Allowed values are ``None``, 0 (which disallows
108 comments immediately), or any positive integer. Default value is
111 .. attribute:: email_notification
113 If ``True``, any new comment on an object of this model which
114 survives moderation (i.e., is not deleted) will generate an
115 email to site staff. Default value is ``False``.
117 .. attribute:: enable_field
119 If this is set to the name of a
120 :class:`~django.db.models.fields.BooleanField` on the model
121 for which comments are being moderated, new comments on
122 objects of that model will be disallowed (immediately deleted)
123 whenever the value of that field is ``False`` on the object
124 the comment would be attached to. Default value is ``None``.
126 .. attribute:: moderate_after
128 If :attr:`auto_moderate_field` is used, this must specify the number
129 of days past the value of the field specified by
130 :attr:`auto_moderate_field` after which new comments for an object
131 should be marked non-public. Allowed values are ``None``, 0 (which
132 moderates comments immediately), or any positive integer. Default
135 Simply subclassing :class:`CommentModerator` and changing the values of these
136 options will automatically enable the various moderation methods for any
137 models registered using the subclass.
139 .. versionchanged:: 1.3
141 ``moderate_after`` and ``close_after`` now accept 0 as a valid value.
143 Adding custom moderation methods
144 --------------------------------
146 For situations where the built-in options listed above are not
147 sufficient, subclasses of :class:`CommentModerator` can also override
148 the methods which actually perform the moderation, and apply any logic
149 they desire. :class:`CommentModerator` defines three methods which
150 determine how moderation will take place; each method will be called
151 by the moderation system and passed two arguments: ``comment``, which
152 is the new comment being posted, ``content_object``, which is the
153 object the comment will be attached to, and ``request``, which is the
154 :class:`~django.http.HttpRequest` in which the comment is being submitted:
156 .. method:: CommentModerator.allow(comment, content_object, request)
158 Should return ``True`` if the comment should be allowed to
159 post on the content object, and ``False`` otherwise (in which
160 case the comment will be immediately deleted).
162 .. method:: CommentModerator.email(comment, content_object, request)
164 If email notification of the new comment should be sent to
165 site staff or moderators, this method is responsible for
168 .. method:: CommentModerator.moderate(comment, content_object, request)
170 Should return ``True`` if the comment should be moderated (in
171 which case its ``is_public`` field will be set to ``False``
172 before saving), and ``False`` otherwise (in which case the
173 ``is_public`` field will not be changed).
176 Registering models for moderation
177 ---------------------------------
179 The moderation system, represented by
180 ``django.contrib.comments.moderation.moderator`` is an instance of the class
181 :class:`Moderator`, which allows registration and "unregistration" of models
184 .. function:: moderator.register(model_or_iterable, moderation_class)
186 Takes two arguments: the first should be either a model class
187 or list of model classes, and the second should be a subclass
188 of ``CommentModerator``, and register the model or models to
189 be moderated using the options defined in the
190 ``CommentModerator`` subclass. If any of the models are
191 already registered for moderation, the exception
192 :exc:`AlreadyModerated` will be raised.
194 .. function:: moderator.unregister(model_or_iterable)
196 Takes one argument: a model class or list of model classes,
197 and removes the model or models from the set of models which
198 are being moderated. If any of the models are not currently
199 being moderated, the exception
200 :exc:`NotModerated` will be raised.
203 Customizing the moderation system
204 ---------------------------------
206 Most use cases will work easily with simple subclassing of
207 :class:`CommentModerator` and registration with the provided
208 :class:`Moderator` instance, but customization of global moderation behavior
209 can be achieved by subclassing :class:`Moderator` and instead registering
210 models with an instance of the subclass.
214 In addition to the :meth:`Moderator.register` and
215 :meth:`Moderator.unregister` methods detailed above, the following methods
216 on :class:`Moderator` can be overridden to achieve customized behavior:
220 Determines how moderation is set up globally. The base
222 :class:`Moderator` does this by
223 attaching listeners to the :data:`~django.contrib.comments.signals.comment_will_be_posted`
224 and :data:`~django.contrib.comments.signals.comment_was_posted` signals from the
227 .. method:: pre_save_moderation(sender, comment, request, **kwargs)
229 In the base implementation, applies all pre-save moderation
230 steps (such as determining whether the comment needs to be
231 deleted, or whether it needs to be marked as non-public or
234 .. method:: post_save_moderation(sender, comment, request, **kwargs)
236 In the base implementation, applies all post-save moderation
237 steps (currently this consists entirely of deleting comments
238 which were disallowed).