newforms-admin: Merged to [4399]

git-svn-id: http://code.djangoproject.com/svn/django/branches/newforms-admin@4400 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/manager.py

@@ -1,4 +1,4 @@
-from django.db.models.query import QuerySet
+from django.db.models.query import QuerySet, EmptyQuerySet
 from django.dispatch import dispatcher
 from django.db.models import signals
 from django.db.models.fields import FieldDoesNotExist
@@ -42,12 +42,18 @@ class Manager(object):
     # PROXIES TO QUERYSET #
     #######################
     
+    def get_empty_query_set(self):
+        return EmptyQuerySet(self.model)
+
     def get_query_set(self):
         """Returns a new QuerySet object.  Subclasses can override this method
         to easily customise the behaviour of the Manager.
         """
         return QuerySet(self.model)
     
+    def none(self):
+        return self.get_empty_query_set()
+
     def all(self):
         return self.get_query_set()
 

django/db/models/query.py

@@ -25,6 +25,9 @@ QUERY_TERMS = (
 # Larger values are slightly faster at the expense of more storage space.
 GET_ITERATOR_CHUNK_SIZE = 100
 
+class EmptyResultSet(Exception):
+    pass
+
 ####################
 # HELPER FUNCTIONS #
 ####################
@@ -168,7 +171,12 @@ class QuerySet(object):
         extra_select = self._select.items()
 
         cursor = connection.cursor()
+        
+        try:
             select, sql, params = self._get_sql_clause()
+        except EmptyResultSet:
+            raise StopIteration
+            
         cursor.execute("SELECT " + (self._distinct and "DISTINCT " or "") + ",".join(select) + sql, params)
         fill_cache = self._select_related
         index_end = len(self.model._meta.fields)
@@ -192,7 +200,12 @@ class QuerySet(object):
         counter._offset = None
         counter._limit = None
         counter._select_related = False
+        
+        try:
             select, sql, params = counter._get_sql_clause()
+        except EmptyResultSet:
+            return 0
+            
         cursor = connection.cursor()
         if self._distinct:
             id_col = "%s.%s" % (backend.quote_name(self.model._meta.db_table),
@@ -523,7 +536,12 @@ class ValuesQuerySet(QuerySet):
             field_names = [f.attname for f in self.model._meta.fields]
 
         cursor = connection.cursor()
+        
+        try:
             select, sql, params = self._get_sql_clause()
+        except EmptyResultSet:
+            raise StopIteration
+        
         select = ['%s.%s' % (backend.quote_name(self.model._meta.db_table), backend.quote_name(c)) for c in columns]
         cursor.execute("SELECT " + (self._distinct and "DISTINCT " or "") + ",".join(select) + sql, params)
         while 1:
@@ -545,7 +563,12 @@ class DateQuerySet(QuerySet):
         if self._field.null:
             self._where.append('%s.%s IS NOT NULL' % \
                 (backend.quote_name(self.model._meta.db_table), backend.quote_name(self._field.column)))
+                
+        try:
             select, sql, params = self._get_sql_clause()
+        except EmptyResultSet:
+            raise StopIteration
+        
         sql = 'SELECT %s %s GROUP BY 1 ORDER BY 1 %s' % \
             (backend.get_date_trunc_sql(self._kind, '%s.%s' % (backend.quote_name(self.model._meta.db_table),
             backend.quote_name(self._field.column))), sql, self._order)
@@ -563,6 +586,25 @@ class DateQuerySet(QuerySet):
         c._order = self._order
         return c
     
+class EmptyQuerySet(QuerySet):
+    def __init__(self, model=None):
+        super(EmptyQuerySet, self).__init__(model)
+        self._result_cache = []
+        
+    def iterator(self):
+        raise StopIteration
+        
+    def count(self):
+        return 0
+        
+    def delete(self):
+        pass
+
+    def _clone(self, klass=None, **kwargs):
+        c = super(EmptyQuerySet, self)._clone(klass, **kwargs)
+        c._result_cache = []
+        return c
+
 class QOperator(object):
     "Base class for QAnd and QOr"
     def __init__(self, *args):
@@ -571,10 +613,14 @@ class QOperator(object):
     def get_sql(self, opts):
         joins, where, params = SortedDict(), [], []
         for val in self.args:
+            try:
                 joins2, where2, params2 = val.get_sql(opts)
                 joins.update(joins2)
                 where.extend(where2)
                 params.extend(params2)
+            except EmptyResultSet:
+                if not isinstance(self, QOr):
+                    raise EmptyResultSet
         if where:
             return joins, ['(%s)' % self.operator.join(where)], params
         return joins, [], params
@@ -628,8 +674,11 @@ class QNot(Q):
         self.q = q
 
     def get_sql(self, opts):
+        try:
             joins, where, params = self.q.get_sql(opts)
             where2 = ['(NOT (%s))' % " AND ".join(where)]
+        except EmptyResultSet:
+            return SortedDict(), [], []
         return joins, where2, params
 
 def get_where_clause(lookup_type, table_prefix, field_name, value):
@@ -645,11 +694,7 @@ def get_where_clause(lookup_type, table_prefix, field_name, value):
         if in_string:
             return '%s%s IN (%s)' % (table_prefix, field_name, in_string)
         else:
-            # Most backends do not accept an empty string inside the IN
-            # expression, i.e. cannot do "WHERE ... IN ()".  Since there are
-            # also some backends that do not accept "WHERE false", we instead
-            # use an expression that always evaluates to False.
-            return '0=1'
+            raise EmptyResultSet
     elif lookup_type == 'range':
         return '%s%s BETWEEN %%s AND %%s' % (table_prefix, field_name)
     elif lookup_type in ('year', 'month', 'day'):

django/oldforms/__init__.py

@@ -569,7 +569,7 @@ class NullBooleanField(SelectField):
     "This SelectField provides 'Yes', 'No' and 'Unknown', mapping results to True, False or None"
     def __init__(self, field_name, is_required=False, validator_list=None):
         if validator_list is None: validator_list = []
-        SelectField.__init__(self, field_name, choices=[('1', 'Unknown'), ('2', 'Yes'), ('3', 'No')],
+        SelectField.__init__(self, field_name, choices=[('1', _('Unknown')), ('2', _('Yes')), ('3', _('No'))],
             is_required=is_required, validator_list=validator_list)
 
     def render(self, data):

docs/db-api.txt

@@ -526,6 +526,21 @@ Examples::
     >>> Entry.objects.filter(headline__contains='Lennon').dates('pub_date', 'day')
     [datetime.datetime(2005, 3, 20)]
     
+``none()``
+~~~~~~~~~~
+
+**New in Django development version**
+
+Returns an ``EmptyQuerySet`` -- a ``QuerySet`` that always evaluates to 
+an empty list. This can be used in cases where you know that you should
+return an empty result set and your caller is expecting a ``QuerySet``
+object (instead of returning an empty list, for example.)
+
+Examples::
+    
+    >>> Entry.objects.none()
+    []
+
 ``select_related()``
 ~~~~~~~~~~~~~~~~~~~~
 

docs/model-api.txt

@@ -1408,7 +1408,10 @@ This should be set to a list of field names that will be searched whenever
 somebody submits a search query in that text box.
 
 These fields should be some kind of text field, such as ``CharField`` or
-``TextField``.
+``TextField``. You can also perform a related lookup on a ``ForeignKey`` with 
+the lookup API "follow" notation::
+
+    search_fields = ['foreign_key__related_fieldname']
 
 When somebody does a search in the admin search box, Django splits the search
 query into words and returns all objects that contain each of the words, case

docs/settings.txt

@@ -557,6 +557,11 @@ Default: ``''`` (Empty string)
 URL that handles the media served from ``MEDIA_ROOT``.
 Example: ``"http://media.lawrence.com"``
 
+Note that this should have a trailing slash if it has a path component.
+
+Good: ``"http://www.example.com/static/"``
+Bad: ``"http://www.example.com/static"``
+
 MIDDLEWARE_CLASSES
 ------------------
 

docs/tutorial03.txt

@@ -260,8 +260,7 @@ provides a shortcut. Here's the full ``index()`` view, rewritten::
         latest_poll_list = Poll.objects.all().order_by('-pub_date')[:5]
         return render_to_response('polls/index.html', {'latest_poll_list': latest_poll_list})
 
-Note that we no longer need to import ``loader``, ``Context`` or
-``HttpResponse``.
+Note that once we've done this in all these views, we no longer need to import ``loader``, ``Context`` and ``HttpResponse``.
 
 The ``render_to_response()`` function takes a template name as its first
 argument and a dictionary as its optional second argument. It returns an

docs/url_dispatch.txt

@@ -393,7 +393,7 @@ to pass metadata and options to views.
 Passing extra options to ``include()``
 --------------------------------------
 
-**New in the Django development version.**
+**New in Django development version.**
 
 Similarly, you can pass extra options to ``include()``. When you pass extra
 options to ``include()``, *each* line in the included URLconf will be passed
@@ -435,7 +435,7 @@ every view in the the included URLconf accepts the extra options you're passing.
 Passing callable objects instead of strings
 ===========================================
 
-**New in the Django development version.**
+**New in Django development version.**
 
 Some developers find it more natural to pass the actual Python function object
 rather than a string containing the path to its module. This alternative is

tests/modeltests/lookup/models.py

@@ -191,4 +191,19 @@ DoesNotExist: Article matching query does not exist.
 >>> Article.objects.filter(headline__contains='\\')
 [<Article: Article with \ backslash>]
 
+# none() returns an EmptyQuerySet that behaves like any other QuerySet object
+>>> Article.objects.none()
+[]
+>>> Article.objects.none().filter(headline__startswith='Article')
+[]
+>>> Article.objects.none().count()
+0
+
+# using __in with an empty list should return an empty query set
+>>> Article.objects.filter(id__in=[])
+[]
+
+>>> Article.objects.exclude(id__in=[])
+[<Article: Article with \ backslash>, <Article: Article% with percent sign>, <Article: Article_ with underscore>, <Article: Article 5>, <Article: Article 6>, <Article: Article 4>, <Article: Article 2>, <Article: Article 3>, <Article: Article 7>, <Article: Article 1>]
+
 """}