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annotate custom_search/receivers.py @ 1200:b9514abc2a67

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Initial commit of ssg101.
author Brian Neal <bgneal@gmail.com>
date Sat, 24 Jun 2023 16:06:51 -0500
parents 78b459d4ab17
children
rev   line source
bgneal@753 1 """This module contains a custom Haystack signal processing class to update the
bgneal@753 2 search index in realtime. We update our search index by enqueuing edits and
bgneal@753 3 deletes into a queue for batch processing. Our class ensures we only enqueue
bgneal@753 4 content that should be in the search index.
bgneal@469 5
bgneal@469 6 """
bgneal@753 7 from django.db.models import signals
bgneal@753 8 import queued_search.signals
bgneal@924 9 import haystack
bgneal@469 10
bgneal@753 11 from bio.signals import profile_content_update
bgneal@753 12 from forums.signals import topic_content_update, post_content_update
bgneal@469 13
bgneal@753 14 import ygroup.models
bgneal@753 15 from weblinks.models import Link
bgneal@753 16 from podcast.models import Item
bgneal@753 17 from news.models import Story
bgneal@753 18 from downloads.models import Download
bgneal@753 19 from forums.models import Forum, Topic, Post
bgneal@753 20 from bio.models import UserProfile
bgneal@753 21
bgneal@753 22
bgneal@753 23 UID = 'custom_search.signals'
bgneal@753 24
bgneal@753 25
bgneal@753 26 class QueuedSignalProcessor(queued_search.signals.QueuedSignalProcessor):
bgneal@469 27 """
bgneal@753 28 This customized version of queued_search's QueuedSignalProcessor
bgneal@753 29 conditionally enqueues items to be indexed.
bgneal@469 30
bgneal@469 31 """
bgneal@753 32 def __init__(self, *args, **kwargs):
bgneal@753 33
bgneal@753 34 # We assume that it is okay to attempt to delete a model from the search
bgneal@753 35 # index even if the model object is not in the index. In other words,
bgneal@753 36 # attempting to delete an object from the index will not cause any
bgneal@753 37 # errors if it is not in the index. Thus if we see an object that has an
bgneal@753 38 # 'is_public' attribute, and it is false, we can safely enqueue a delete
bgneal@753 39 # in case the 'is_public' attribute just went from True to False. We
bgneal@753 40 # have no way of knowing that, it could have been False all along, but we
bgneal@753 41 # just try the delete in case to be safe.
bgneal@753 42
bgneal@753 43 # To make the code easier to read, use a table to drive our signal
bgneal@753 44 # connecting and disconnecting:
bgneal@753 45 self.signal_chain = [
bgneal@753 46 # Yahoo Group posts are always updated:
bgneal@753 47 (signals.post_save, ygroup.models.Post, self.enqueue_save),
bgneal@753 48 (signals.post_delete, ygroup.models.Post, self.enqueue_delete),
bgneal@753 49
bgneal@753 50 # Weblink Links are updated if they are public:
bgneal@753 51 (signals.post_save, Link, self.enqueue_public_save),
bgneal@753 52 (signals.post_delete, Link, self.enqueue_delete),
bgneal@753 53
bgneal@753 54 # Podcast Items are always updated:
bgneal@753 55 (signals.post_save, Item, self.enqueue_save),
bgneal@753 56 (signals.post_delete, Item, self.enqueue_delete),
bgneal@753 57
bgneal@753 58 # News Stories are always updated:
bgneal@753 59 (signals.post_save, Story, self.enqueue_save),
bgneal@753 60 (signals.post_delete, Story, self.enqueue_delete),
bgneal@753 61
bgneal@753 62 # Downloads are updated if they are public:
bgneal@753 63 (signals.post_save, Download, self.enqueue_public_save),
bgneal@753 64 (signals.post_delete, Download, self.enqueue_delete),
bgneal@753 65
bgneal@753 66 # Forum Topics are updated if they belong to a public forum:
bgneal@753 67 (topic_content_update, None, self.enqueue_topic_save),
bgneal@753 68 (signals.post_delete, Topic, self.enqueue_delete),
bgneal@753 69
bgneal@753 70 # Forum Posts are updated if they belong to a public forum:
bgneal@753 71 (post_content_update, None, self.enqueue_post_save),
bgneal@753 72 (signals.post_delete, Post, self.enqueue_delete),
bgneal@753 73
bgneal@753 74 # UserProfiles are updated when we receive a special signal:
bgneal@753 75 (profile_content_update, None, self.enqueue_profile),
bgneal@753 76 (signals.post_delete, UserProfile, self.enqueue_delete),
bgneal@753 77 ]
bgneal@753 78
bgneal@753 79 super(QueuedSignalProcessor, self).__init__(*args, **kwargs)
bgneal@753 80
bgneal@753 81 def setup(self):
bgneal@753 82 """We override setup() so we can attach signal handlers to only the
bgneal@753 83 models we search on. In some cases we have custom signals to tell us
bgneal@753 84 when to update the search index.
bgneal@469 85
bgneal@469 86 """
bgneal@753 87 for signal, sender, receiver in self.signal_chain:
bgneal@753 88 signal.connect(receiver, sender=sender, dispatch_uid=UID)
bgneal@469 89
bgneal@753 90 def teardown(self):
bgneal@753 91 """Disconnect all signals we previously connected."""
bgneal@753 92 for signal, sender, receiver in self.signal_chain:
bgneal@753 93 signal.disconnect(receiver, sender=sender, dispatch_uid=UID)
bgneal@753 94
bgneal@753 95 def enqueue_public_save(self, sender, instance, **kwargs):
bgneal@753 96 """Index only if the instance is_public.
bgneal@753 97
bgneal@753 98 If not, enqueue a delete just in case the is_public flag got flipped
bgneal@753 99 from True to False.
bgneal@469 100
bgneal@469 101 """
bgneal@753 102 if instance.is_public:
bgneal@753 103 self.enqueue_save(sender, instance, **kwargs)
bgneal@753 104 else:
bgneal@753 105 self.enqueue_delete(sender, instance, **kwargs)
bgneal@677 106
bgneal@753 107 def enqueue_topic_save(self, sender, **kwargs):
bgneal@753 108 """Enqueue only if the topic instance belongs to a public forum."""
bgneal@753 109 if sender.forum.id in Forum.objects.public_forum_ids():
bgneal@753 110 self.enqueue_save(Topic, sender, **kwargs)
bgneal@677 111
bgneal@753 112 def enqueue_post_save(self, sender, **kwargs):
bgneal@753 113 """Enqueue only if the post instance belongs to a public forum."""
bgneal@753 114 if sender.topic.forum.id in Forum.objects.public_forum_ids():
bgneal@753 115 self.enqueue_save(Post, sender, **kwargs)
bgneal@677 116
bgneal@753 117 def enqueue_profile(self, sender, **kwargs):
bgneal@753 118 """Forward the user profile instance on unconditionally."""
bgneal@753 119 self.enqueue_save(UserProfile, sender, **kwargs)
bgneal@924 120
bgneal@924 121
bgneal@924 122 # Starting with Django 1.7, we'd see Django generate warnings if we defined
bgneal@924 123 # a HAYSTACK_SIGNAL_PROCESSOR in our settings that referenced the class above.
bgneal@924 124 # This is because Haystack creates an instance of our signal processor class
bgneal@924 125 # (defined above) at import time, and thus imports this module very early in the
bgneal@924 126 # application startup sequence. Warnings are then generated when this module
bgneal@924 127 # imports our models, some of whose applications have not been imported yet.
bgneal@924 128 # This problem will presumably go away when Haystack can fully support Django
bgneal@924 129 # 1.7.x and implements an AppConfig with a ready() method. Until then, we don't
bgneal@924 130 # use Haystack's signal processor object; we'll just create one here. This
bgneal@924 131 # module will be imported when our custom_search app's ready() method runs.
bgneal@924 132
bgneal@924 133 signal_processor = QueuedSignalProcessor(haystack.connections,
bgneal@924 134 haystack.connection_router)