1 files changed, 85 insertions, 0 deletions
diff --git a/forum/models/tag.py b/forum/models/tag.py
new file mode 100755
index 00000000..28b9e572
--- /dev/null
+++ b/forum/models/tag.py
@@ -0,0 +1,85 @@
+from base import *
+
+from django.utils.translation import ugettext as _
+
+class TagManager(models.Manager):
+    UPDATE_USED_COUNTS_QUERY = (
+        'UPDATE tag '
+        'SET used_count = ('
+            'SELECT COUNT(*) FROM question_tags '
+            'INNER JOIN question ON question_id=question.id '
+            'WHERE tag_id = tag.id AND question.deleted=False'
+        ') '
+        'WHERE id IN (%s)')
+
+    def get_valid_tags(self, page_size):
+      tags = self.all().filter(deleted=False).exclude(used_count=0).order_by("-id")[:page_size]
+      return tags
+
+    def get_or_create_multiple(self, names, user):
+        """
+        Fetches a list of Tags with the given names, creating any Tags
+        which don't exist when necesssary.
+        """
+        tags = list(self.filter(name__in=names))
+        #Set all these tag visible
+        for tag in tags:
+            if tag.deleted:
+                tag.deleted = False
+                tag.deleted_by = None
+                tag.deleted_at = None
+                tag.save()
+
+        if len(tags) < len(names):
+            existing_names = set(tag.name for tag in tags)
+            new_names = [name for name in names if name not in existing_names]
+            tags.extend([self.create(name=name, created_by=user)
+                         for name in new_names if self.filter(name=name).count() == 0 and len(name.strip()) > 0])
+
+        return tags
+
+    def update_use_counts(self, tags):
+        """Updates the given Tags with their current use counts."""
+        if not tags:
+            return
+        cursor = connection.cursor()
+        query = self.UPDATE_USED_COUNTS_QUERY % ','.join(['%s'] * len(tags))
+        cursor.execute(query, [tag.id for tag in tags])
+        transaction.commit_unless_managed()
+
+    def get_tags_by_questions(self, questions):
+        question_ids = []
+        for question in questions:
+            question_ids.append(question.id)
+
+        question_ids_str = ','.join([str(id) for id in question_ids])
+        related_tags = self.extra(
+                tables=['tag', 'question_tags'],
+                where=["tag.id = question_tags.tag_id AND question_tags.question_id IN (" + question_ids_str + ")"]
+        ).distinct()
+
+        return related_tags
+
+class Tag(DeletableContent):
+    name            = models.CharField(max_length=255, unique=True)
+    created_by      = models.ForeignKey(User, related_name='created_tags')
+    # Denormalised data
+    used_count = models.PositiveIntegerField(default=0)
+
+    objects = TagManager()
+
+    class Meta(DeletableContent.Meta):
+        db_table = u'tag'
+        ordering = ('-used_count', 'name')
+
+    def __unicode__(self):
+        return self.name
+
+class MarkedTag(models.Model):
+    TAG_MARK_REASONS = (('good',_('interesting')),('bad',_('ignored')))
+    tag = models.ForeignKey('Tag', related_name='user_selections')
+    user = models.ForeignKey(User, related_name='tag_selections')
+    reason = models.CharField(max_length=16, choices=TAG_MARK_REASONS)
+
+    class Meta:
+        app_label = 'forum'
+\ No newline at end of file