Fixed #3193 -- newforms: Modified as_hidden() to handle MultipleChoiceField correctly. Thanks for the report, Honza Kral

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4298 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/newforms/fields.py

@@ -4,7 +4,7 @@ Field classes
 
 from django.utils.translation import gettext
 from util import ValidationError, smart_unicode
-from widgets import TextInput, PasswordInput, CheckboxInput, Select, SelectMultiple
+from widgets import TextInput, PasswordInput, HiddenInput, MultipleHiddenInput, CheckboxInput, Select, SelectMultiple
 import datetime
 import re
 import time
@@ -29,6 +29,7 @@ except NameError:
 
 class Field(object):
     widget = TextInput # Default widget to use when rendering this type of Field.
+    hidden_widget = HiddenInput # Default widget to use when rendering this as "hidden".
 
     # Tracks each time a Field instance is created. Used to retain order.
     creation_counter = 0
@@ -336,6 +337,8 @@ class ChoiceField(Field):
         return value
 
 class MultipleChoiceField(ChoiceField):
+    hidden_widget = MultipleHiddenInput
+
     def __init__(self, choices=(), required=True, widget=SelectMultiple, label=None, initial=None):
         ChoiceField.__init__(self, choices, required, widget, label, initial)
 

django/newforms/forms.py

@@ -5,7 +5,7 @@ Form classes
 from django.utils.datastructures import SortedDict, MultiValueDict
 from django.utils.html import escape
 from fields import Field
-from widgets import TextInput, Textarea, HiddenInput
+from widgets import TextInput, Textarea, HiddenInput, MultipleHiddenInput
 from util import StrAndUnicode, ErrorDict, ErrorList, ValidationError
 
 __all__ = ('BaseForm', 'Form')
@@ -238,7 +238,7 @@ class BoundField(StrAndUnicode):
         """
         Returns a string of HTML for representing this as an <input type="hidden">.
         """
-        return self.as_widget(HiddenInput(), attrs)
+        return self.as_widget(self.field.hidden_widget(), attrs)
 
     def _data(self):
         """

django/newforms/widgets.py

@@ -3,8 +3,8 @@ HTML Widget classes
 """
 
 __all__ = (
-    'Widget', 'TextInput', 'PasswordInput', 'HiddenInput', 'FileInput',
+    'Widget', 'TextInput', 'PasswordInput', 'HiddenInput', 'MultipleHiddenInput',
-    'Textarea', 'CheckboxInput',
+    'FileInput', 'Textarea', 'CheckboxInput',
     'Select', 'SelectMultiple', 'RadioSelect', 'CheckboxSelectMultiple',
 )
 
@@ -87,6 +87,16 @@ class HiddenInput(Input):
     input_type = 'hidden'
     is_hidden = True
 
+class MultipleHiddenInput(HiddenInput):
+    """
+    A widget that handles <input type="hidden"> for fields that have a list
+    of values.
+    """
+    def render(self, name, value, attrs=None):
+        if value is None: value = []
+        final_attrs = self.build_attrs(attrs, type=self.input_type, name=name)
+        return u'\n'.join([(u'<input%s />' % flatatt(dict(value=smart_unicode(v), **final_attrs))) for v in value])
+
 class FileInput(Input):
     input_type = 'file'
 

tests/regressiontests/forms/tests.py

@@ -1849,6 +1849,17 @@ MultipleChoiceField is a special case, as its data is required to be a list:
 <option value="P" selected="selected">Paul McCartney</option>
 </select>
 
+MultipleChoiceField rendered as_hidden() is a special case. Because it can
+have multiple values, its as_hidden() renders multiple <input type="hidden">
+tags.
+>>> f = SongForm({'name': 'Yesterday', 'composers': ['P']}, auto_id=False)
+>>> print f['composers'].as_hidden()
+<input type="hidden" name="composers" value="P" />
+>>> f = SongForm({'name': 'From Me To You', 'composers': ['P', 'J']}, auto_id=False)
+>>> print f['composers'].as_hidden()
+<input type="hidden" name="composers" value="P" />
+<input type="hidden" name="composers" value="J" />
+
 MultipleChoiceField can also be used with the CheckboxSelectMultiple widget.
 >>> class SongForm(Form):
 ...     name = CharField()
@@ -1905,6 +1916,8 @@ returns a list of input.
 >>> f.clean_data
 {'composers': [u'J', u'P'], 'name': u'Yesterday'}
 
+# Validating multiple fields in relation to another ###########################
+
 There are a couple of ways to do multiple-field validation. If you want the
 validation message to be associated with a particular field, implement the
 clean_XXX() method on the Form, where XXX is the field name. As in