From c0e01416b68e482172ef23cc507f163b873c192a Mon Sep 17 00:00:00 2001
From: Adrian Holovaty <adrian@holovaty.com>
Date: Sat, 27 Jan 2007 21:41:32 +0000
Subject: [PATCH] Fixed #3312 -- CheckboxSelectMultiple no longer uses
 duplicate ID attributes for each checkbox

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4436 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/newforms/widgets.py           |  9 +++++++--
 tests/regressiontests/forms/tests.py | 10 ++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/django/newforms/widgets.py b/django/newforms/widgets.py
index 3c27f7e2c11..585e12cc181 100644
--- a/django/newforms/widgets.py
+++ b/django/newforms/widgets.py
@@ -258,11 +258,16 @@ class RadioSelect(Select):
 class CheckboxSelectMultiple(SelectMultiple):
     def render(self, name, value, attrs=None, choices=()):
         if value is None: value = []
+        has_id = attrs and attrs.has_key('id')
         final_attrs = self.build_attrs(attrs, name=name)
         output = [u'<ul>']
         str_values = set([smart_unicode(v) for v in value]) # Normalize to strings.
-        cb = CheckboxInput(final_attrs, check_test=lambda value: value in str_values)
-        for option_value, option_label in chain(self.choices, choices):
+        for i, (option_value, option_label) in enumerate(chain(self.choices, choices)):
+            # If an ID attribute was given, add a numeric index as a suffix,
+            # so that the checkboxes don't all have the same ID attribute.
+            if has_id:
+                final_attrs = dict(final_attrs, id='%s_%s' % (attrs['id'], i))
+            cb = CheckboxInput(final_attrs, check_test=lambda value: value in str_values)
             option_value = smart_unicode(option_value)
             rendered_cb = cb.render(name, option_value)
             output.append(u'<li><label>%s %s</label></li>' % (rendered_cb, escape(smart_unicode(option_label))))
diff --git a/tests/regressiontests/forms/tests.py b/tests/regressiontests/forms/tests.py
index 328582d162a..f60898c1799 100644
--- a/tests/regressiontests/forms/tests.py
+++ b/tests/regressiontests/forms/tests.py
@@ -2149,6 +2149,16 @@ MultipleChoiceField can also be used with the CheckboxSelectMultiple widget.
 <li><label><input checked="checked" type="checkbox" name="composers" value="P" /> Paul McCartney</label></li>
 </ul>
 
+Regarding auto_id, CheckboxSelectMultiple is a special case. Each checkbox
+gets a distinct ID, formed by appending an underscore plus the checkbox's
+zero-based index.
+>>> f = SongForm(auto_id='%s_id')
+>>> print f['composers']
+<ul>
+<li><label><input type="checkbox" name="composers" value="J" id="composers_id_0" /> John Lennon</label></li>
+<li><label><input type="checkbox" name="composers" value="P" id="composers_id_1" /> Paul McCartney</label></li>
+</ul>
+
 Data for a MultipleChoiceField should be a list. QueryDict and MultiValueDict
 conveniently work with this.
 >>> data = {'name': 'Yesterday', 'composers': ['J', 'P']}