added grappelli, filebrowser, chunks and tagging to lcal repo

1 files changed, 490 insertions, 0 deletions

diff --git a/lib/tagging/models.py b/lib/tagging/models.py
new file mode 100644
index 0000000..860cf81
--- /dev/null
+++ b/lib/tagging/models.py
@@ -0,0 +1,490 @@
+"""
+Models and managers for generic tagging.
+"""
+# Python 2.3 compatibility
+try:
+    set
+except NameError:
+    from sets import Set as set
+
+from django.contrib.contenttypes import generic
+from django.contrib.contenttypes.models import ContentType
+from django.db import connection, models
+from django.db.models.query import QuerySet
+from django.utils.translation import ugettext_lazy as _
+
+from tagging import settings
+from tagging.utils import calculate_cloud, get_tag_list, get_queryset_and_model, parse_tag_input
+from tagging.utils import LOGARITHMIC
+
+qn = connection.ops.quote_name
+
+############
+# Managers #
+############
+
+class TagManager(models.Manager):
+    def update_tags(self, obj, tag_names):
+        """
+        Update tags associated with an object.
+        """
+        ctype = ContentType.objects.get_for_model(obj)
+        current_tags = list(self.filter(items__content_type__pk=ctype.pk,
+                                        items__object_id=obj.pk))
+        updated_tag_names = parse_tag_input(tag_names)
+        if settings.FORCE_LOWERCASE_TAGS:
+            updated_tag_names = [t.lower() for t in updated_tag_names]
+
+        # Remove tags which no longer apply
+        tags_for_removal = [tag for tag in current_tags \
+                            if tag.name not in updated_tag_names]
+        if len(tags_for_removal):
+            TaggedItem._default_manager.filter(content_type__pk=ctype.pk,
+                                               object_id=obj.pk,
+                                               tag__in=tags_for_removal).delete()
+        # Add new tags
+        current_tag_names = [tag.name for tag in current_tags]
+        for tag_name in updated_tag_names:
+            if tag_name not in current_tag_names:
+                tag, created = self.get_or_create(name=tag_name)
+                TaggedItem._default_manager.create(tag=tag, object=obj)
+
+    def add_tag(self, obj, tag_name):
+        """
+        Associates the given object with a tag.
+        """
+        tag_names = parse_tag_input(tag_name)
+        if not len(tag_names):
+            raise AttributeError(_('No tags were given: "%s".') % tag_name)
+        if len(tag_names) > 1:
+            raise AttributeError(_('Multiple tags were given: "%s".') % tag_name)
+        tag_name = tag_names[0]
+        if settings.FORCE_LOWERCASE_TAGS:
+            tag_name = tag_name.lower()
+        tag, created = self.get_or_create(name=tag_name)
+        ctype = ContentType.objects.get_for_model(obj)
+        TaggedItem._default_manager.get_or_create(
+            tag=tag, content_type=ctype, object_id=obj.pk)
+
+    def get_for_object(self, obj):
+        """
+        Create a queryset matching all tags associated with the given
+        object.
+        """
+        ctype = ContentType.objects.get_for_model(obj)
+        return self.filter(items__content_type__pk=ctype.pk,
+                           items__object_id=obj.pk)
+
+    def _get_usage(self, model, counts=False, min_count=None, extra_joins=None, extra_criteria=None, params=None):
+        """
+        Perform the custom SQL query for ``usage_for_model`` and
+        ``usage_for_queryset``.
+        """
+        if min_count is not None: counts = True
+
+        model_table = qn(model._meta.db_table)
+        model_pk = '%s.%s' % (model_table, qn(model._meta.pk.column))
+        query = """
+        SELECT DISTINCT %(tag)s.id, %(tag)s.name%(count_sql)s
+        FROM
+            %(tag)s
+            INNER JOIN %(tagged_item)s
+                ON %(tag)s.id = %(tagged_item)s.tag_id
+            INNER JOIN %(model)s
+                ON %(tagged_item)s.object_id = %(model_pk)s
+            %%s
+        WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
+            %%s
+        GROUP BY %(tag)s.id, %(tag)s.name
+        %%s
+        ORDER BY %(tag)s.name ASC""" % {
+            'tag': qn(self.model._meta.db_table),
+            'count_sql': counts and (', COUNT(%s)' % model_pk) or '',
+            'tagged_item': qn(TaggedItem._meta.db_table),
+            'model': model_table,
+            'model_pk': model_pk,
+            'content_type_id': ContentType.objects.get_for_model(model).pk,
+        }
+
+        min_count_sql = ''
+        if min_count is not None:
+            min_count_sql = 'HAVING COUNT(%s) >= %%s' % model_pk
+            params.append(min_count)
+
+        cursor = connection.cursor()
+        cursor.execute(query % (extra_joins, extra_criteria, min_count_sql), params)
+        tags = []
+        for row in cursor.fetchall():
+            t = self.model(*row[:2])
+            if counts:
+                t.count = row[2]
+            tags.append(t)
+        return tags
+
+    def usage_for_model(self, model, counts=False, min_count=None, filters=None):
+        """
+        Obtain a list of tags associated with instances of the given
+        Model class.
+
+        If ``counts`` is True, a ``count`` attribute will be added to
+        each tag, indicating how many times it has been used against
+        the Model class in question.
+
+        If ``min_count`` is given, only tags which have a ``count``
+        greater than or equal to ``min_count`` will be returned.
+        Passing a value for ``min_count`` implies ``counts=True``.
+
+        To limit the tags (and counts, if specified) returned to those
+        used by a subset of the Model's instances, pass a dictionary
+        of field lookups to be applied to the given Model as the
+        ``filters`` argument.
+        """
+        if filters is None: filters = {}
+
+        queryset = model._default_manager.filter()
+        for f in filters.items():
+            queryset.query.add_filter(f)
+        usage = self.usage_for_queryset(queryset, counts, min_count)
+
+        return usage
+
+    def usage_for_queryset(self, queryset, counts=False, min_count=None):
+        """
+        Obtain a list of tags associated with instances of a model
+        contained in the given queryset.
+
+        If ``counts`` is True, a ``count`` attribute will be added to
+        each tag, indicating how many times it has been used against
+        the Model class in question.
+
+        If ``min_count`` is given, only tags which have a ``count``
+        greater than or equal to ``min_count`` will be returned.
+        Passing a value for ``min_count`` implies ``counts=True``.
+        """
+
+        if getattr(queryset.query, 'get_compiler', None):
+            # Django 1.2+
+            compiler = queryset.query.get_compiler(using='default')
+            extra_joins = ' '.join(compiler.get_from_clause()[0][1:])
+            where, params = queryset.query.where.as_sql(
+                compiler.quote_name_unless_alias, compiler.connection
+            )
+        else:
+            # Django pre-1.2
+            extra_joins = ' '.join(queryset.query.get_from_clause()[0][1:])
+            where, params = queryset.query.where.as_sql()
+
+        if where:
+            extra_criteria = 'AND %s' % where
+        else:
+            extra_criteria = ''
+        return self._get_usage(queryset.model, counts, min_count, extra_joins, extra_criteria, params)
+
+    def related_for_model(self, tags, model, counts=False, min_count=None):
+        """
+        Obtain a list of tags related to a given list of tags - that
+        is, other tags used by items which have all the given tags.
+
+        If ``counts`` is True, a ``count`` attribute will be added to
+        each tag, indicating the number of items which have it in
+        addition to the given list of tags.
+
+        If ``min_count`` is given, only tags which have a ``count``
+        greater than or equal to ``min_count`` will be returned.
+        Passing a value for ``min_count`` implies ``counts=True``.
+        """
+        if min_count is not None: counts = True
+        tags = get_tag_list(tags)
+        tag_count = len(tags)
+        tagged_item_table = qn(TaggedItem._meta.db_table)
+        query = """
+        SELECT %(tag)s.id, %(tag)s.name%(count_sql)s
+        FROM %(tagged_item)s INNER JOIN %(tag)s ON %(tagged_item)s.tag_id = %(tag)s.id
+        WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
+          AND %(tagged_item)s.object_id IN
+          (
+              SELECT %(tagged_item)s.object_id
+              FROM %(tagged_item)s, %(tag)s
+              WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
+                AND %(tag)s.id = %(tagged_item)s.tag_id
+                AND %(tag)s.id IN (%(tag_id_placeholders)s)
+              GROUP BY %(tagged_item)s.object_id
+              HAVING COUNT(%(tagged_item)s.object_id) = %(tag_count)s
+          )
+          AND %(tag)s.id NOT IN (%(tag_id_placeholders)s)
+        GROUP BY %(tag)s.id, %(tag)s.name
+        %(min_count_sql)s
+        ORDER BY %(tag)s.name ASC""" % {
+            'tag': qn(self.model._meta.db_table),
+            'count_sql': counts and ', COUNT(%s.object_id)' % tagged_item_table or '',
+            'tagged_item': tagged_item_table,
+            'content_type_id': ContentType.objects.get_for_model(model).pk,
+            'tag_id_placeholders': ','.join(['%s'] * tag_count),
+            'tag_count': tag_count,
+            'min_count_sql': min_count is not None and ('HAVING COUNT(%s.object_id) >= %%s' % tagged_item_table) or '',
+        }
+
+        params = [tag.pk for tag in tags] * 2
+        if min_count is not None:
+            params.append(min_count)
+
+        cursor = connection.cursor()
+        cursor.execute(query, params)
+        related = []
+        for row in cursor.fetchall():
+            tag = self.model(*row[:2])
+            if counts is True:
+                tag.count = row[2]
+            related.append(tag)
+        return related
+
+    def cloud_for_model(self, model, steps=4, distribution=LOGARITHMIC,
+                        filters=None, min_count=None):
+        """
+        Obtain a list of tags associated with instances of the given
+        Model, giving each tag a ``count`` attribute indicating how
+        many times it has been used and a ``font_size`` attribute for
+        use in displaying a tag cloud.
+
+        ``steps`` defines the range of font sizes - ``font_size`` will
+        be an integer between 1 and ``steps`` (inclusive).
+
+        ``distribution`` defines the type of font size distribution
+        algorithm which will be used - logarithmic or linear. It must
+        be either ``tagging.utils.LOGARITHMIC`` or
+        ``tagging.utils.LINEAR``.
+
+        To limit the tags displayed in the cloud to those associated
+        with a subset of the Model's instances, pass a dictionary of
+        field lookups to be applied to the given Model as the
+        ``filters`` argument.
+
+        To limit the tags displayed in the cloud to those with a
+        ``count`` greater than or equal to ``min_count``, pass a value
+        for the ``min_count`` argument.
+        """
+        tags = list(self.usage_for_model(model, counts=True, filters=filters,
+                                         min_count=min_count))
+        return calculate_cloud(tags, steps, distribution)
+
+class TaggedItemManager(models.Manager):
+    """
+    FIXME There's currently no way to get the ``GROUP BY`` and ``HAVING``
+          SQL clauses required by many of this manager's methods into
+          Django's ORM.
+
+          For now, we manually execute a query to retrieve the PKs of
+          objects we're interested in, then use the ORM's ``__in``
+          lookup to return a ``QuerySet``.
+
+          Now that the queryset-refactor branch is in the trunk, this can be
+          tidied up significantly.
+    """
+    def get_by_model(self, queryset_or_model, tags):
+        """
+        Create a ``QuerySet`` containing instances of the specified
+        model associated with a given tag or list of tags.
+        """
+        tags = get_tag_list(tags)
+        tag_count = len(tags)
+        if tag_count == 0:
+            # No existing tags were given
+            queryset, model = get_queryset_and_model(queryset_or_model)
+            return model._default_manager.none()
+        elif tag_count == 1:
+            # Optimisation for single tag - fall through to the simpler
+            # query below.
+            tag = tags[0]
+        else:
+            return self.get_intersection_by_model(queryset_or_model, tags)
+
+        queryset, model = get_queryset_and_model(queryset_or_model)
+        content_type = ContentType.objects.get_for_model(model)
+        opts = self.model._meta
+        tagged_item_table = qn(opts.db_table)
+        return queryset.extra(
+            tables=[opts.db_table],
+            where=[
+                '%s.content_type_id = %%s' % tagged_item_table,
+                '%s.tag_id = %%s' % tagged_item_table,
+                '%s.%s = %s.object_id' % (qn(model._meta.db_table),
+                                          qn(model._meta.pk.column),
+                                          tagged_item_table)
+            ],
+            params=[content_type.pk, tag.pk],
+        )
+
+    def get_intersection_by_model(self, queryset_or_model, tags):
+        """
+        Create a ``QuerySet`` containing instances of the specified
+        model associated with *all* of the given list of tags.
+        """
+        tags = get_tag_list(tags)
+        tag_count = len(tags)
+        queryset, model = get_queryset_and_model(queryset_or_model)
+
+        if not tag_count:
+            return model._default_manager.none()
+
+        model_table = qn(model._meta.db_table)
+        # This query selects the ids of all objects which have all the
+        # given tags.
+        query = """
+        SELECT %(model_pk)s
+        FROM %(model)s, %(tagged_item)s
+        WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
+          AND %(tagged_item)s.tag_id IN (%(tag_id_placeholders)s)
+          AND %(model_pk)s = %(tagged_item)s.object_id
+        GROUP BY %(model_pk)s
+        HAVING COUNT(%(model_pk)s) = %(tag_count)s""" % {
+            'model_pk': '%s.%s' % (model_table, qn(model._meta.pk.column)),
+            'model': model_table,
+            'tagged_item': qn(self.model._meta.db_table),
+            'content_type_id': ContentType.objects.get_for_model(model).pk,
+            'tag_id_placeholders': ','.join(['%s'] * tag_count),
+            'tag_count': tag_count,
+        }
+
+        cursor = connection.cursor()
+        cursor.execute(query, [tag.pk for tag in tags])
+        object_ids = [row[0] for row in cursor.fetchall()]
+        if len(object_ids) > 0:
+            return queryset.filter(pk__in=object_ids)
+        else:
+            return model._default_manager.none()
+
+    def get_union_by_model(self, queryset_or_model, tags):
+        """
+        Create a ``QuerySet`` containing instances of the specified
+        model associated with *any* of the given list of tags.
+        """
+        tags = get_tag_list(tags)
+        tag_count = len(tags)
+        queryset, model = get_queryset_and_model(queryset_or_model)
+
+        if not tag_count:
+            return model._default_manager.none()
+
+        model_table = qn(model._meta.db_table)
+        # This query selects the ids of all objects which have any of
+        # the given tags.
+        query = """
+        SELECT %(model_pk)s
+        FROM %(model)s, %(tagged_item)s
+        WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
+          AND %(tagged_item)s.tag_id IN (%(tag_id_placeholders)s)
+          AND %(model_pk)s = %(tagged_item)s.object_id
+        GROUP BY %(model_pk)s""" % {
+            'model_pk': '%s.%s' % (model_table, qn(model._meta.pk.column)),
+            'model': model_table,
+            'tagged_item': qn(self.model._meta.db_table),
+            'content_type_id': ContentType.objects.get_for_model(model).pk,
+            'tag_id_placeholders': ','.join(['%s'] * tag_count),
+        }
+
+        cursor = connection.cursor()
+        cursor.execute(query, [tag.pk for tag in tags])
+        object_ids = [row[0] for row in cursor.fetchall()]
+        if len(object_ids) > 0:
+            return queryset.filter(pk__in=object_ids)
+        else:
+            return model._default_manager.none()
+
+    def get_related(self, obj, queryset_or_model, num=None):
+        """
+        Retrieve a list of instances of the specified model which share
+        tags with the model instance ``obj``, ordered by the number of
+        shared tags in descending order.
+
+        If ``num`` is given, a maximum of ``num`` instances will be
+        returned.
+        """
+        queryset, model = get_queryset_and_model(queryset_or_model)
+        model_table = qn(model._meta.db_table)
+        content_type = ContentType.objects.get_for_model(obj)
+        related_content_type = ContentType.objects.get_for_model(model)
+        query = """
+        SELECT %(model_pk)s, COUNT(related_tagged_item.object_id) AS %(count)s
+        FROM %(model)s, %(tagged_item)s, %(tag)s, %(tagged_item)s related_tagged_item
+        WHERE %(tagged_item)s.object_id = %%s
+          AND %(tagged_item)s.content_type_id = %(content_type_id)s
+          AND %(tag)s.id = %(tagged_item)s.tag_id
+          AND related_tagged_item.content_type_id = %(related_content_type_id)s
+          AND related_tagged_item.tag_id = %(tagged_item)s.tag_id
+          AND %(model_pk)s = related_tagged_item.object_id"""
+        if content_type.pk == related_content_type.pk:
+            # Exclude the given instance itself if determining related
+            # instances for the same model.
+            query += """
+          AND related_tagged_item.object_id != %(tagged_item)s.object_id"""
+        query += """
+        GROUP BY %(model_pk)s
+        ORDER BY %(count)s DESC
+        %(limit_offset)s"""
+        query = query % {
+            'model_pk': '%s.%s' % (model_table, qn(model._meta.pk.column)),
+            'count': qn('count'),
+            'model': model_table,
+            'tagged_item': qn(self.model._meta.db_table),
+            'tag': qn(self.model._meta.get_field('tag').rel.to._meta.db_table),
+            'content_type_id': content_type.pk,
+            'related_content_type_id': related_content_type.pk,
+            # Hardcoding this for now just to get tests working again - this
+            # should now be handled by the query object.
+            'limit_offset': num is not None and 'LIMIT %s' or '',
+        }
+
+        cursor = connection.cursor()
+        params = [obj.pk]
+        if num is not None:
+            params.append(num)
+        cursor.execute(query, params)
+        object_ids = [row[0] for row in cursor.fetchall()]
+        if len(object_ids) > 0:
+            # Use in_bulk here instead of an id__in lookup, because id__in would
+            # clobber the ordering.
+            object_dict = queryset.in_bulk(object_ids)
+            return [object_dict[object_id] for object_id in object_ids \
+                    if object_id in object_dict]
+        else:
+            return []
+
+##########
+# Models #
+##########
+
+class Tag(models.Model):
+    """
+    A tag.
+    """
+    name = models.CharField(_('name'), max_length=50, unique=True, db_index=True)
+
+    objects = TagManager()
+
+    class Meta:
+        ordering = ('name',)
+        verbose_name = _('tag')
+        verbose_name_plural = _('tags')
+
+    def __unicode__(self):
+        return self.name
+
+class TaggedItem(models.Model):
+    """
+    Holds the relationship between a tag and the item being tagged.
+    """
+    tag          = models.ForeignKey(Tag, verbose_name=_('tag'), related_name='items')
+    content_type = models.ForeignKey(ContentType, verbose_name=_('content type'))
+    object_id    = models.PositiveIntegerField(_('object id'), db_index=True)
+    object       = generic.GenericForeignKey('content_type', 'object_id')
+
+    objects = TaggedItemManager()
+
+    class Meta:
+        # Enforce unique tag association per object
+        unique_together = (('tag', 'content_type', 'object_id'),)
+        verbose_name = _('tagged item')
+        verbose_name_plural = _('tagged items')
+
+    def __unicode__(self):
+        return u'%s [%s]' % (self.object, self.tag)