- Added librarian as a submodule.

[wolnelektury.git] / apps / newtagging / models.py

diff --git a/apps/newtagging/models.py b/apps/newtagging/models.py
index 5385e95..1c35254 100644 (file)
--- a/apps/newtagging/models.py
+++ b/apps/newtagging/models.py
@@ -1,8 +1,12 @@
+# -*- coding: utf-8 -*-

 """
 Models and managers for generic tagging.
 """
 """
 Models and managers for generic tagging.
 """

+

 # Python 2.3 compatibility
 # Python 2.3 compatibility

-if not hasattr(__builtins__, 'set'):
+try:
+    set
+except NameError:

     from sets import Set as set
 
 from django.contrib.contenttypes import generic
     from sets import Set as set
 
 from django.contrib.contenttypes import generic


@@ -10,6 +14,7 @@ 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.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

 
 qn = connection.ops.quote_name
 
 
 qn = connection.ops.quote_name
 


@@ -40,7 +45,7 @@ class TagManager(models.Manager):
     def __init__(self, intermediary_table_model):
         super(TagManager, self).__init__()
         self.intermediary_table_model = intermediary_table_model
     def __init__(self, intermediary_table_model):
         super(TagManager, self).__init__()
         self.intermediary_table_model = intermediary_table_model

-    
+

     def update_tags(self, obj, tags):
         """
         Update tags associated with an object.
     def update_tags(self, obj, tags):
         """
         Update tags associated with an object.


@@ -49,7 +54,7 @@ class TagManager(models.Manager):
         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)
         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)

-    
+

         # Remove tags which no longer apply
         tags_for_removal = [tag for tag in current_tags \
                             if tag not in updated_tags]
         # Remove tags which no longer apply
         tags_for_removal = [tag for tag in current_tags \
                             if tag not in updated_tags]


@@ -61,7 +66,15 @@ class TagManager(models.Manager):
         for tag in updated_tags:
             if tag not in current_tags:
                 self.intermediary_table_model._default_manager.create(tag=tag, content_object=obj)
         for tag in updated_tags:
             if tag not in current_tags:
                 self.intermediary_table_model._default_manager.create(tag=tag, content_object=obj)

-    
+
+    def remove_tag(self, obj, tag):
+        """
+        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()
+

     def get_for_object(self, obj):
         """
         Create a queryset matching all tags associated with the given
     def get_for_object(self, obj):
         """
         Create a queryset matching all tags associated with the given


@@ -70,7 +83,7 @@ class TagManager(models.Manager):
         ctype = ContentType.objects.get_for_model(obj)
         return self.filter(items__content_type__pk=ctype.pk,
                            items__object_id=obj.pk)
         ctype = ContentType.objects.get_for_model(obj)
         return self.filter(items__content_type__pk=ctype.pk,
                            items__object_id=obj.pk)

-    
+

     def _get_usage(self, model, counts=False, min_count=None, extra_joins=None, extra_criteria=None, params=None, extra=None):
         """
         Perform the custom SQL query for ``usage_for_model`` and
     def _get_usage(self, model, counts=False, min_count=None, extra_joins=None, extra_criteria=None, params=None, extra=None):
         """
         Perform the custom SQL query for ``usage_for_model`` and


@@ -81,12 +94,12 @@ class TagManager(models.Manager):
         model_table = qn(model._meta.db_table)
         model_pk = '%s.%s' % (model_table, qn(model._meta.pk.column))
         tag_columns = self._get_tag_columns()
         model_table = qn(model._meta.db_table)
         model_pk = '%s.%s' % (model_table, qn(model._meta.pk.column))
         tag_columns = self._get_tag_columns()

-        
+

         if extra is None: extra = {}
         extra_where = ''
         if 'where' in extra:
             extra_where = 'AND ' + ' AND '.join(extra['where'])
         if extra is None: extra = {}
         extra_where = ''
         if 'where' in extra:
             extra_where = 'AND ' + ' AND '.join(extra['where'])

-        
+

         query = """
         SELECT DISTINCT %(tag_columns)s%(count_sql)s
         FROM
         query = """
         SELECT DISTINCT %(tag_columns)s%(count_sql)s
         FROM


@@ -99,7 +112,7 @@ class TagManager(models.Manager):
         WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
             %%s
             %(extra_where)s
         WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
             %%s
             %(extra_where)s

-        GROUP BY %(tag)s.id, %(tag)s.name
+        GROUP BY %(tag_columns)s, %(tag)s.id, %(tag)s.name

         %%s
         ORDER BY %(tag)s.%(ordering)s ASC""" % {
             'tag': qn(self.model._meta.db_table),
         %%s
         ORDER BY %(tag)s.%(ordering)s ASC""" % {
             'tag': qn(self.model._meta.db_table),


@@ -211,28 +224,33 @@ class TagManager(models.Manager):
         tag_count = len(tags)
         tagged_item_table = qn(self.intermediary_table_model._meta.db_table)
         tag_columns = self._get_tag_columns()
         tag_count = len(tags)
         tagged_item_table = qn(self.intermediary_table_model._meta.db_table)
         tag_columns = self._get_tag_columns()

-        
+

         if extra is None: extra = {}
         extra_where = ''
         if 'where' in extra:
             extra_where = 'AND ' + ' AND '.join(extra['where'])
         if extra is None: extra = {}
         extra_where = ''
         if 'where' in extra:
             extra_where = 'AND ' + ' AND '.join(extra['where'])

-        
+
+        # Temporary table in this query is a hack to prevent MySQL from executing
+        # inner query as dependant query (which could result in severe performance loss)

         query = """
         SELECT %(tag_columns)s%(count_sql)s
         FROM %(tagged_item)s INNER JOIN %(tag)s ON %(tagged_item)s.tag_id = %(tag)s.id
         WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
         query = """
         SELECT %(tag_columns)s%(count_sql)s
         FROM %(tagged_item)s INNER JOIN %(tag)s ON %(tagged_item)s.tag_id = %(tag)s.id
         WHERE %(tagged_item)s.content_type_id = %(content_type_id)s

-          AND %(tagged_item)s.object_id IN
-          (
-              SELECT %(tagged_item)s.object_id
-              FROM %(tagged_item)s, %(tag)s
-              WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
-                AND %(tag)s.id = %(tagged_item)s.tag_id
-                AND %(tag)s.id IN (%(tag_id_placeholders)s)
-              GROUP BY %(tagged_item)s.object_id
-              HAVING COUNT(%(tagged_item)s.object_id) = %(tag_count)s
-          )
-          AND %(tag)s.id NOT IN (%(tag_id_placeholders)s)
-          %(extra_where)s
+        AND %(tagged_item)s.object_id IN
+        (
+            SELECT *
+            FROM (
+                SELECT %(tagged_item)s.object_id
+                FROM %(tagged_item)s, %(tag)s
+                WHERE %(tagged_item)s.content_type_id = %(content_type_id)s
+                  AND %(tag)s.id = %(tagged_item)s.tag_id
+                  AND %(tag)s.id IN (%(tag_id_placeholders)s)
+                GROUP BY %(tagged_item)s.object_id
+                HAVING COUNT(%(tagged_item)s.object_id) = %(tag_count)s
+            ) AS temporary
+        )
+        AND %(tag)s.id NOT IN (%(tag_id_placeholders)s)
+        %(extra_where)s

         GROUP BY %(tag_columns)s
         %(min_count_sql)s
         ORDER BY %(tag)s.%(ordering)s ASC""" % {
         GROUP BY %(tag_columns)s
         %(min_count_sql)s
         ORDER BY %(tag)s.%(ordering)s ASC""" % {


@@ -283,7 +301,7 @@ class TaggedItemManager(models.Manager):
     def __init__(self, tag_model):
         super(TaggedItemManager, self).__init__()
         self.tag_model = tag_model
     def __init__(self, tag_model):
         super(TaggedItemManager, self).__init__()
         self.tag_model = tag_model

-    
+

     def get_by_model(self, queryset_or_model, tags):
         """
         Create a ``QuerySet`` containing instances of the specified
     def get_by_model(self, queryset_or_model, tags):
         """
         Create a ``QuerySet`` containing instances of the specified


@@ -455,15 +473,18 @@ class TaggedItemManager(models.Manager):
 def create_intermediary_table_model(model):
     """Create an intermediary table model for the specific tag model"""
     name = model.__name__ + 'Relation'
 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'),)
 
     def obj_unicode(self):
     class Meta:
         db_table = '%s_relation' % model._meta.db_table
         unique_together = (('tag', 'content_type', 'object_id'),)
 
     def obj_unicode(self):

-        return u'%s [%s]' % (self.content_type.get_object_for_this_type(pk=self.object_id), self.tag)
-        
-    # Set up a dictionary to simulate declarations within a class    
+        try:
+            return u'%s [%s]' % (self.content_type.get_object_for_this_type(pk=self.object_id), self.tag)
+        except ObjectDoesNotExist:
+            return u'<deleted> [%s]' % self.tag
+
+    # Set up a dictionary to simulate declarations within a class

     attrs = {
         '__module__': model.__module__,
         'Meta': Meta,
     attrs = {
         '__module__': model.__module__,
         'Meta': Meta,


@@ -492,15 +513,15 @@ class TagMeta(ModelBase):
 class TagBase(models.Model):
     """Abstract class to be inherited by model classes."""
     __metaclass__ = TagMeta
 class TagBase(models.Model):
     """Abstract class to be inherited by model classes."""
     __metaclass__ = TagMeta

-    
+

     class Meta:
         abstract = True
     class Meta:
         abstract = True

-    
+

     @staticmethod
     def get_tag_list(tag_list):
         """
         Utility function for accepting tag input in a flexible manner.
     @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):
         You should probably override this method in your subclass.
         """
         if isinstance(tag_list, TagBase):