annotate news/utils.py @ 1164:68811c583bfb

WIP forum to V3 design commit.
author Brian Neal <bgneal@gmail.com>
date Wed, 12 Apr 2017 20:26:45 -0500
parents c6c3ba5cf6eb
children
rev   line source
bgneal@399 1 """
bgneal@399 2 Common utility/helper code for the news app.
bgneal@399 3
bgneal@399 4 """
bgneal@399 5 from django.contrib.contenttypes.models import ContentType
bgneal@399 6
bgneal@399 7 from comments.models import Comment
bgneal@399 8 from tagging.models import TaggedItem
bgneal@399 9 from news.models import Story
bgneal@399 10
bgneal@399 11
bgneal@399 12 def attach_extra_attrs(stories):
bgneal@399 13 """
bgneal@399 14 For each story in the input stories list, attach 2 new attributes:
bgneal@399 15 tag_list and comment_count. The tags and comment count info is pulled from
bgneal@399 16 the database in bulk. This saves database queries when lots of news
bgneal@399 17 stories are displayed at once. For best results, use ".defer('tags')"
bgneal@399 18 when retrieve the stories from the database.
bgneal@399 19
bgneal@399 20 """
bgneal@399 21 stories_dict = dict((story.id, story) for story in stories)
bgneal@399 22 story_ids = stories_dict.keys()
bgneal@399 23
bgneal@399 24 # Get all the tags out in one query
bgneal@399 25 ct = ContentType.objects.get_for_model(Story)
bgneal@399 26 tagged_items = TaggedItem.objects.filter(content_type=ct,
bgneal@399 27 object_id__in=story_ids).select_related('tag')
bgneal@399 28
bgneal@399 29 for story in stories_dict.values():
bgneal@399 30 story.tag_list = []
bgneal@1001 31 if story.version == 0:
bgneal@1001 32 story.comment_count = 0
bgneal@1001 33 elif story.forums_topic:
bgneal@1001 34 # for convenience/consistency with old models...
bgneal@1001 35 story.comment_count = story.forums_comment_count()
bgneal@399 36
bgneal@399 37 # attach tags
bgneal@399 38 for item in tagged_items:
bgneal@399 39 stories_dict[item.object_id].tag_list.append(item.tag.name)
bgneal@399 40
bgneal@1001 41 # Now get all the comment counts out in one fell swoop. This is only needed
bgneal@1001 42 # for older news stories...
bgneal@399 43
bgneal@1001 44 story_ids = [pk for pk in story_ids if stories_dict[pk].version == 0]
bgneal@399 45
bgneal@1001 46 if story_ids:
bgneal@1001 47 story_ids = Comment.objects.filter(content_type=ct,
bgneal@1001 48 object_id__in=story_ids).values_list('object_id', flat=True)
bgneal@1001 49
bgneal@1001 50 # compute comment_count
bgneal@1001 51 for story_id in story_ids:
bgneal@1001 52 stories_dict[story_id].comment_count += 1