+++ /dev/null
-# -*- coding: utf-8 -*-
-"""
-Custom managers for Django models registered with the tagging
-application.
-"""
-from django.contrib.contenttypes.models import ContentType
-from django.db import models
-
-
-class ModelTagManager(models.Manager):
- """
- A manager for retrieving tags for a particular model.
- """
- def __init__(self, tag_model):
- super(ModelTagManager, self).__init__()
- self.tag_model = tag_model
-
- def get_query_set(self):
- content_type = ContentType.objects.get_for_model(self.model)
- return self.tag_model.objects.filter(
- items__content_type__pk=content_type.pk).distinct()
-
- def related(self, tags, *args, **kwargs):
- return self.tag_model.objects.related_for_model(tags, self.model, *args, **kwargs)
-
- def usage(self, *args, **kwargs):
- return self.tag_model.objects.usage_for_model(self.model, *args, **kwargs)
-
-
-class ModelTaggedItemManager(models.Manager):
- """
- A manager for retrieving model instances based on their tags.
- """
- def __init__(self, tag_model):
- super(ModelTaggedItemManager, self).__init__()
- self.intermediary_table_model = tag_model.objects.intermediary_table_model
-
- def related_to(self, obj, queryset=None, num=None):
- if queryset is None:
- return self.intermediary_table_model.objects.get_related(obj, self.model, num=num)
- else:
- return self.intermediary_table_model.objects.get_related(obj, queryset, num=num)
-
- def with_all(self, tags, queryset=None):
- if queryset is None:
- return self.intermediary_table_model.objects.get_by_model(self.model, tags)
- else:
- return self.intermediary_table_model.objects.get_by_model(queryset, tags)
-
- def with_any(self, tags, queryset=None):
- if queryset is None:
- return self.intermediary_table_model.objects.get_union_by_model(self.model, tags)
- else:
- return self.intermediary_table_model.objects.get_union_by_model(queryset, tags)
-
-
-class TagDescriptor(object):
- """
- A descriptor which provides access to a ``ModelTagManager`` for
- model classes and simple retrieval, updating and deletion of tags
- for model instances.
- """
- def __init__(self, tag_model):
- self.tag_model = tag_model
-
- def __get__(self, instance, owner):
- if not instance:
- tag_manager = ModelTagManager(self.tag_model)
- tag_manager.model = owner
- return tag_manager
- else:
- return self.tag_model.objects.get_for_object(instance)
-
- def __set__(self, instance, value):
- self.tag_model.objects.update_tags(instance, value)
-
- def __del__(self, instance):
- self.tag_model.objects.update_tags(instance, [])
-