Changeset 4552

Timestamp:

02/20/07 23:14:28 (2 years ago)

Author:

adrian

Message:

Fixed #3534 -- newforms ModelChoiceField? and ModelMultipleChoiceField? no longer cache choices. Instead, they calculate choices via a fresh database query each time the widget is rendered and clean() is called

Files:

• django/trunk/django/newforms/models.py (modified) (2 diffs)
• django/trunk/tests/modeltests/model_forms/models.py (modified) (5 diffs)

django/trunk/django/newforms/models.py

@@ -4 +4 @@
-"""
-
+from django.utils.translation import gettext
+from util import ValidationError
-from forms import BaseForm, DeclarativeFieldsMetaclass, SortedDictFromList
-ChoiceField, Multiple
-
+Field, 
+, MultipleHiddenInput
-
-__all__ = ('save_instance', 'form_for_model', 'form_for_instance', 'form_for_fields',
@@ -105 +107 @@
-    return type('FormForFields', (BaseForm,), {'base_fields': fields})
-
+class QuerySetIterator(object):
+    def __init__(self, queryset, empty_label, cache_choices):
+        self.queryset, self.empty_label, self.cache_choices = queryset, empty_label, cache_choices
+
+    def __iter__(self):
+        if self.empty_label is not None:
+            yield (u"", self.empty_label)
+        for obj in self.queryset:
+            yield (obj._get_pk_val(), str(obj))
+        # Clear the QuerySet cache if required.
+        if not self.cache_choices:
+            self.queryset._result_cache = None
+
-class ModelChoiceField(ChoiceField):
-    "A ChoiceField whose choices are a model QuerySet."
-
-
-
-
-
-
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+
-
-    def clean(self, value):
-value = Choice
-not value
+
+value in ('', None)
-            return None
-        try:
-
-
+queryset.
+queryset.
-            raise ValidationError(gettext(u'Select a valid choice. That choice is not one of the available choices.'))
-        return value
-
-ultiple
+odel
-    "A MultipleChoiceField whose choices are a model QuerySet."
-
-
-
+
+
+
+
+
-
-    def clean(self, value):
-
-
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+
+
-            return []
-
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+

django/trunk/tests/modeltests/model_forms/models.py

@@ -290 +290 @@
-<Category: Third>
-
+Here, we demonstrate that choices for a ForeignKey ChoiceField are determined
+at runtime, based on the data in the database when the form is displayed, not
+the data in the database when the form is instantiated.
+>>> ArticleForm = form_for_model(Article)
+>>> f = ArticleForm(auto_id=False)
+>>> print f.as_ul()
+<li>Headline: <input type="text" name="headline" maxlength="50" /></li>
+<li>Pub date: <input type="text" name="pub_date" /></li>
+<li>Writer: <select name="writer">
+<option value="" selected="selected">---------</option>
+<option value="1">Mike Royko</option>
+<option value="2">Bob Woodward</option>
+</select></li>
+<li>Article: <textarea name="article"></textarea></li>
+<li>Categories: <select multiple="multiple" name="categories">
+<option value="1">Entertainment</option>
+<option value="2">It&#39;s a test</option>
+<option value="3">Third</option>
+</select>  Hold down "Control", or "Command" on a Mac, to select more than one.</li>
+>>> Category.objects.create(name='Fourth', url='4th')
+<Category: Fourth>
+>>> Writer.objects.create(name='Carl Bernstein')
+<Writer: Carl Bernstein>
+>>> print f.as_ul()
+<li>Headline: <input type="text" name="headline" maxlength="50" /></li>
+<li>Pub date: <input type="text" name="pub_date" /></li>
+<li>Writer: <select name="writer">
+<option value="" selected="selected">---------</option>
+<option value="1">Mike Royko</option>
+<option value="2">Bob Woodward</option>
+<option value="3">Carl Bernstein</option>
+</select></li>
+<li>Article: <textarea name="article"></textarea></li>
+<li>Categories: <select multiple="multiple" name="categories">
+<option value="1">Entertainment</option>
+<option value="2">It&#39;s a test</option>
+<option value="3">Third</option>
+<option value="4">Fourth</option>
+</select>  Hold down "Control", or "Command" on a Mac, to select more than one.</li>
+
-# ModelChoiceField ############################################################
-
@@ -311 +351 @@
->>> f.clean(2)
-<Category: It's a test>
+
+# Add a Category object *after* the ModelChoiceField has already been
+# instantiated. This proves clean() checks the database during clean() rather
+# than caching it at time of instantiation.
+>>> Category.objects.create(name='Fifth', url='5th')
+<Category: Fifth>
+>>> f.clean(5)
+<Category: Fifth>
+
+# Delete a Category object *after* the ModelChoiceField has already been
+# instantiated. This proves clean() checks the database during clean() rather
+# than caching it at time of instantiation.
+>>> Category.objects.get(url='5th').delete()
+>>> f.clean(5)
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. That choice is not one of the available choices.']
-
->>> f = ModelChoiceField(Category.objects.filter(pk=1), required=False)
@@ -318 +375 @@
->>> f.clean('1')
-<Category: Entertainment>
-2
+100
-Traceback (most recent call last):
-...
@@ -346 +403 @@
->>> f.clean((1, '2'))
-[<Category: Entertainment>, <Category: It's a test>]
-nonexistent
-
-
-nonexistent
+100
+
+
+100
->>> f.clean('hello')
-Traceback (most recent call last):
-...
-ValidationError: [u'Enter a list of values.']
+
+# Add a Category object *after* the ModelChoiceField has already been
+# instantiated. This proves clean() checks the database during clean() rather
+# than caching it at time of instantiation.
+>>> Category.objects.create(id=6, name='Sixth', url='6th')
+<Category: Sixth>
+>>> f.clean([6])
+[<Category: Sixth>]
+
+# Delete a Category object *after* the ModelChoiceField has already been
+# instantiated. This proves clean() checks the database during clean() rather
+# than caching it at time of instantiation.
+>>> Category.objects.get(url='6th').delete()
+>>> f.clean([6])
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. 6 is not one of the available choices.']
+
->>> f = ModelMultipleChoiceField(Category.objects.all(), required=False)
->>> f.clean([])
@@ -359 +434 @@
->>> f.clean(())
-[]
-4
-
-
-4
-4
-
-
-4
-5
-
-
-5
+10
+
+
+10
+10
+
+
+10
+10
+
+
+10
-"""}