From 6645d1fe48868814e4c73056b68be5c3861ed2d0 Mon Sep 17 00:00:00 2001
From: Adrian Holovaty <adrian@holovaty.com>
Date: Thu, 2 Nov 2006 03:16:12 +0000
Subject: [PATCH] Added ChoiceField, MultipleChoiceField to django.newforms

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3959 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/newforms/__init__.py          |   1 -
 django/newforms/fields.py            |  56 ++++++++++++++-
 tests/regressiontests/forms/tests.py | 100 +++++++++++++++++++++++++++
 3 files changed, 155 insertions(+), 2 deletions(-)

diff --git a/django/newforms/__init__.py b/django/newforms/__init__.py
index f0eca9a950..9d12c55ae9 100644
--- a/django/newforms/__init__.py
+++ b/django/newforms/__init__.py
@@ -3,7 +3,6 @@ Django validation and HTML form handling.
 
 TODO:
     Validation not tied to a particular field
-    <select> and validation of lists
     Default value for field
     Field labels
     Nestable Forms
diff --git a/django/newforms/fields.py b/django/newforms/fields.py
index 29ede3a0c1..83867dccc3 100644
--- a/django/newforms/fields.py
+++ b/django/newforms/fields.py
@@ -3,7 +3,7 @@ Field classes
 """
 
 from util import ValidationError, DEFAULT_ENCODING
-from widgets import TextInput, CheckboxInput
+from widgets import TextInput, CheckboxInput, Select, SelectMultiple
 import datetime
 import re
 import time
@@ -13,11 +13,17 @@ __all__ = (
     'DEFAULT_DATE_INPUT_FORMATS', 'DateField',
     'DEFAULT_DATETIME_INPUT_FORMATS', 'DateTimeField',
     'RegexField', 'EmailField', 'URLField', 'BooleanField',
+    'ChoiceField', 'MultipleChoiceField',
 )
 
 # These values, if given to to_python(), will trigger the self.required check.
 EMPTY_VALUES = (None, '')
 
+try:
+    set # Only available in Python 2.4+
+except NameError:
+    from sets import Set as set # Python 2.3 fallback
+
 class Field(object):
     widget = TextInput # Default widget to use when rendering this type of Field.
 
@@ -205,3 +211,51 @@ class BooleanField(Field):
         "Returns a Python boolean object."
         Field.to_python(self, value)
         return bool(value)
+
+class ChoiceField(Field):
+    def __init__(self, choices=(), required=True, widget=Select):
+        if isinstance(widget, type):
+            widget = widget(choices=choices)
+        Field.__init__(self, required, widget)
+        self.choices = choices
+
+    def to_python(self, value):
+        """
+        Validates that the input is in self.choices.
+        """
+        value = Field.to_python(self, value)
+        if value in EMPTY_VALUES: value = u''
+        if not isinstance(value, basestring):
+            value = unicode(str(value), DEFAULT_ENCODING)
+        elif not isinstance(value, unicode):
+            value = unicode(value, DEFAULT_ENCODING)
+        valid_values = set([str(k) for k, v in self.choices])
+        if value not in valid_values:
+            raise ValidationError(u'Select a valid choice. %s is not one of the available choices.' % value)
+        return value
+
+class MultipleChoiceField(ChoiceField):
+    def __init__(self, choices=(), required=True, widget=SelectMultiple):
+        ChoiceField.__init__(self, choices, required, widget)
+
+    def to_python(self, value):
+        """
+        Validates that the input is a list or tuple.
+        """
+        if not isinstance(value, (list, tuple)):
+            raise ValidationError(u'Enter a list of values.')
+        if self.required and not value:
+            raise ValidationError(u'This field is required.')
+        new_value = []
+        for val in value:
+            if not isinstance(val, basestring):
+                value = unicode(str(val), DEFAULT_ENCODING)
+            elif not isinstance(val, unicode):
+                value = unicode(val, DEFAULT_ENCODING)
+            new_value.append(value)
+        # Validate that each value in the value list is in self.choices.
+        valid_values = set([k for k, v in self.choices])
+        for val in new_value:
+            if val not in valid_values:
+                raise ValidationError(u'Select a valid choice. %s is not one of the available choices.' % val)
+        return new_value
diff --git a/tests/regressiontests/forms/tests.py b/tests/regressiontests/forms/tests.py
index 49907cd9e9..92f66af213 100644
--- a/tests/regressiontests/forms/tests.py
+++ b/tests/regressiontests/forms/tests.py
@@ -680,6 +680,64 @@ False
 >>> f.to_python('Django rocks')
 True
 
+# ChoiceField #################################################################
+
+>>> f = ChoiceField(choices=[('1', '1'), ('2', '2')])
+>>> f.to_python(1)
+u'1'
+>>> f.to_python('1')
+u'1'
+>>> f.to_python(None)
+Traceback (most recent call last):
+...
+ValidationError: [u'This field is required.']
+>>> f.to_python('')
+Traceback (most recent call last):
+...
+ValidationError: [u'This field is required.']
+>>> f.to_python('3')
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. 3 is not one of the available choices.']
+
+>>> f = ChoiceField(choices=[('J', 'John'), ('P', 'Paul')])
+>>> f.to_python('J')
+u'J'
+>>> f.to_python('John')
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. John is not one of the available choices.']
+
+# MultipleChoiceField #########################################################
+
+>>> f = MultipleChoiceField(choices=[('1', '1'), ('2', '2')])
+>>> f.to_python([1])
+[u'1']
+>>> f.to_python(['1'])
+[u'1']
+>>> f.to_python(['1', '2'])
+[u'1', u'2']
+>>> f.to_python([1, '2'])
+[u'1', u'2']
+>>> f.to_python((1, '2'))
+[u'1', u'2']
+>>> f.to_python('hello')
+Traceback (most recent call last):
+...
+ValidationError: [u'Enter a list of values.']
+>>> f.to_python([])
+Traceback (most recent call last):
+...
+ValidationError: [u'This field is required.']
+>>> f.to_python(())
+Traceback (most recent call last):
+...
+ValidationError: [u'This field is required.']
+>>> f.to_python(['3'])
+Traceback (most recent call last):
+...
+ValidationError: [u'Select a valid choice. 3 is not one of the available choices.']
+
 # Form ########################################################################
 
 >>> class Person(Form):
@@ -787,6 +845,48 @@ u'<textarea name="subject">Hello</textarea>'
 >>> f['message'].as_text()
 u'<input type="text" name="message" value="I love you." />'
 
+For a form with a <select>, use ChoiceField:
+>>> class FrameworkForm(Form):
+...     name = CharField()
+...     language = ChoiceField(choices=[('P', 'Python'), ('J', 'Java')])
+>>> f = FrameworkForm()
+>>> print f['language']
+<select name="language">
+<option value="P">Python</option>
+<option value="J">Java</option>
+</select>
+>>> f = FrameworkForm({'name': 'Django', 'language': 'P'})
+>>> print f['language']
+<select name="language">
+<option value="P" selected="selected">Python</option>
+<option value="J">Java</option>
+</select>
+
+MultipleChoiceField is a special case, as its data is required to be a list:
+>>> class SongForm(Form):
+...     name = CharField()
+...     composers = MultipleChoiceField()
+>>> f = SongForm()
+>>> print f['composers']
+<select multiple="multiple" name="composers">
+</select>
+>>> class SongForm(Form):
+...     name = CharField()
+...     composers = MultipleChoiceField(choices=[('J', 'John Lennon'), ('P', 'Paul McCartney')])
+>>> f = SongForm()
+>>> print f['composers']
+<select multiple="multiple" name="composers">
+<option value="J">John Lennon</option>
+<option value="P">Paul McCartney</option>
+</select>
+>>> f = SongForm({'name': 'Yesterday', 'composers': ['P']})
+>>> print f['name']
+<input type="text" name="name" value="Yesterday" />
+>>> print f['composers']
+<select multiple="multiple" name="composers">
+<option value="J">John Lennon</option>
+<option value="P" selected="selected">Paul McCartney</option>
+</select>
 """
 
 if __name__ == "__main__":