X-Git-Url: https://git.mdrn.pl/wolnelektury.git/blobdiff_plain/357027375ff8867f42ca34bcbfb5a78b5b185fc3..e852900e42eb0bde98daf7070d84816e44c3308e:/src/newtagging/models.py diff --git a/src/newtagging/models.py b/src/newtagging/models.py index 694f5b868..e3e8f3c0a 100644 --- a/src/newtagging/models.py +++ b/src/newtagging/models.py @@ -1,21 +1,20 @@ -# -*- coding: utf-8 -*- +# This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later. +# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information. +# """ Models and managers for generic tagging. """ -from django.contrib.contenttypes.fields import GenericForeignKey from django.contrib.contenttypes.models import ContentType from django.db import connection, models -from django.utils.translation import ugettext_lazy as _ from django.db.models.base import ModelBase -from django.core.exceptions import ObjectDoesNotExist from django.dispatch import Signal qn = connection.ops.quote_name - tags_updated = Signal(providing_args=["affected_tags"]) + def get_queryset_and_model(queryset_or_model): """ Given a ``QuerySet`` or a ``Model``, returns a two-tuple of @@ -27,18 +26,21 @@ def get_queryset_and_model(queryset_or_model): try: return queryset_or_model, queryset_or_model.model except AttributeError: - return queryset_or_model._default_manager.all(), queryset_or_model + return queryset_or_model.objects.all(), queryset_or_model ############ # Managers # ############ class TagManager(models.Manager): - def __init__(self, intermediary_table_model): + def __init__(self): super(TagManager, self).__init__() - self.intermediary_table_model = intermediary_table_model models.signals.pre_delete.connect(self.target_deleted) + @property + def intermediary_table_model(self): + return self.model.intermediary_table_model + def target_deleted(self, instance, **kwargs): """ clear tag relations before deleting an object """ try: @@ -55,21 +57,22 @@ class TagManager(models.Manager): content_type = ContentType.objects.get_for_model(obj) current_tags = list(self.filter(items__content_type__pk=content_type.pk, items__object_id=obj.pk)) - updated_tags = self.model.get_tag_list(tags) + updated_tags = tags # Remove tags which no longer apply - tags_for_removal = [tag for tag in current_tags \ - if tag not in updated_tags] + tags_for_removal = [tag for tag in current_tags if tag not in updated_tags] if len(tags_for_removal): - self.intermediary_table_model._default_manager.filter(content_type__pk=content_type.pk, - object_id=obj.pk, - tag__in=tags_for_removal).delete() + self.intermediary_table_model.objects.filter( + content_type__pk=content_type.pk, + object_id=obj.pk, + tag__in=tags_for_removal).delete() # Add new tags - tags_to_add = [tag for tag in updated_tags - if tag not in current_tags] + tags_to_add = [tag for tag in updated_tags if tag not in current_tags] for tag in tags_to_add: - if tag not in current_tags: - self.intermediary_table_model._default_manager.create(tag=tag, content_object=obj) + existing = self.intermediary_table_model.objects.filter( + content_type__pk=content_type.pk, object_id=obj.pk, tag=tag) + if not existing: + self.intermediary_table_model.objects.create(tag=tag, content_object=obj) tags_updated.send(sender=type(obj), instance=obj, affected_tags=tags_to_add + tags_for_removal) @@ -78,8 +81,18 @@ class TagManager(models.Manager): Remove tag from an object. """ content_type = ContentType.objects.get_for_model(obj) - self.intermediary_table_model._default_manager.filter(content_type__pk=content_type.pk, - object_id=obj.pk, tag=tag).delete() + self.intermediary_table_model.objects.filter( + content_type__pk=content_type.pk, object_id=obj.pk, tag=tag).delete() + + def add_tag(self, obj, tag): + """ + Add tag to an object. + """ + content_type = ContentType.objects.get_for_model(obj) + relations = self.intermediary_table_model.objects.filter( + content_type__pk=content_type.pk, object_id=obj.pk, tag=tag) + if not relations: + self.intermediary_table_model.objects.create(tag=tag, content_object=obj) def get_for_object(self, obj): """ @@ -105,9 +118,10 @@ class TagManager(models.Manager): ``filters`` argument. """ # TODO: Do we really need this filters stuff? - if filters is None: filters = {} + if filters is None: + filters = {} - queryset = model._default_manager.filter() + queryset = model.objects.filter() for f in filters.items(): queryset.query.add_filter(f) usage = self.usage_for_queryset(queryset, counts) @@ -122,10 +136,9 @@ class TagManager(models.Manager): each tag, indicating how many times it has been used against the Model class in question. """ - usage = self.model._default_manager.filter( + usage = self.model.objects.filter( items__content_type=ContentType.objects.get_for_model(queryset.model), - items__object_id__in=queryset - ) + items__object_id__in=queryset) if counts: usage = usage.annotate(count=models.Count('id')) else: @@ -148,9 +161,9 @@ class TagManager(models.Manager): class TaggedItemManager(models.Manager): - def __init__(self, tag_model): - super(TaggedItemManager, self).__init__() - self.tag_model = tag_model + @property + def tag_model(self): + return self.model.tag_model def get_by_model(self, queryset_or_model, tags): """ @@ -158,7 +171,6 @@ class TaggedItemManager(models.Manager): model associated with a given tag or list of tags. """ queryset, model = get_queryset_and_model(queryset_or_model) - tags = self.tag_model.get_tag_list(tags) if not tags: # No existing tags were given return queryset.none() @@ -175,7 +187,6 @@ class TaggedItemManager(models.Manager): model associated with *any* of the given list of tags. """ queryset, model = get_queryset_and_model(queryset_or_model) - tags = self.tag_model.get_tag_list(tags) if not tags: return queryset.none() # TODO: presumes reverse generic relation @@ -192,68 +203,3 @@ class TaggedItemManager(models.Manager): # Do we know it's 'tags'? return queryset.filter(tag_relations__tag__in=obj.tags).annotate( count=models.Count('pk')).order_by('-count').exclude(pk=obj.pk) - - -########## -# Models # -########## -def create_intermediary_table_model(model): - """Create an intermediary table model for the specific tag model""" - name = model.__name__ + 'Relation' - - class Meta: - db_table = '%s_relation' % model._meta.db_table - unique_together = (('tag', 'content_type', 'object_id'),) - app_label = model._meta.app_label - - def obj_unicode(self): - try: - return u'%s [%s]' % (self.content_type.get_object_for_this_type(pk=self.object_id), self.tag) - except ObjectDoesNotExist: - return u' [%s]' % self.tag - - # Set up a dictionary to simulate declarations within a class - attrs = { - '__module__': model.__module__, - 'Meta': Meta, - 'tag': models.ForeignKey(model, verbose_name=_('tag'), related_name='items'), - 'content_type': models.ForeignKey(ContentType, verbose_name=_('content type')), - 'object_id': models.PositiveIntegerField(_('object id'), db_index=True), - 'content_object': GenericForeignKey('content_type', 'object_id'), - '__unicode__': obj_unicode, - } - - return type(name, (models.Model,), attrs) - - -class TagMeta(ModelBase): - "Metaclass for tag models (models inheriting from TagBase)." - def __new__(mcs, name, bases, attrs): - model = super(TagMeta, mcs).__new__(mcs, name, bases, attrs) - if not model._meta.abstract: - # Create an intermediary table and register custom managers for concrete models - model.intermediary_table_model = create_intermediary_table_model(model) - TagManager(model.intermediary_table_model).contribute_to_class(model, 'objects') - TaggedItemManager(model).contribute_to_class(model.intermediary_table_model, 'objects') - return model - - -class TagBase(models.Model): - """Abstract class to be inherited by model classes.""" - __metaclass__ = TagMeta - - class Meta: - abstract = True - - @staticmethod - def get_tag_list(tag_list): - """ - Utility function for accepting tag input in a flexible manner. - - You should probably override this method in your subclass. - """ - if isinstance(tag_list, TagBase): - return [tag_list] - else: - return tag_list -