Implemented SelectMultiple in django.newforms.widgets

git-svn-id: http://code.djangoproject.com/svn/django/trunk@3958 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/newforms/widgets.py

@@ -2,16 +2,26 @@
 HTML Widget classes
 """
 
-__all__ = ('Widget', 'TextInput', 'PasswordInput', 'HiddenInput', 'FileInput', 'Textarea', 'CheckboxInput', 'Select')
+__all__ = (
+    'Widget', 'TextInput', 'PasswordInput', 'HiddenInput', 'FileInput',
+    'Textarea', 'CheckboxInput',
+    'Select', 'SelectMultiple',
+)
 
 from django.utils.html import escape
 from itertools import chain
 
+try:
+    set # Only available in Python 2.4+
+except NameError:
+    from sets import Set as set # Python 2.3 fallback
+
 # Converts a dictionary to a single string with key="value", XML-style.
 # Assumes keys do not need to be XML-escaped.
 flatatt = lambda attrs: ' '.join(['%s="%s"' % (k, escape(v)) for k, v in attrs.items()])
 
 class Widget(object):
+    requires_data_list = False # Determines whether render()'s 'value' argument should be a list.
     def __init__(self, attrs=None):
         self.attrs = attrs or {}
 
@@ -70,14 +80,31 @@ class Select(Widget):
             final_attrs.update(attrs)
         output = [u'<select %s>' % flatatt(final_attrs)]
         str_value = str(value) # Normalize to string.
-        for option_value, option_label,  in chain(self.choices, choices):
+        for option_value, option_label in chain(self.choices, choices):
             selected_html = (str(option_value) == str_value) and ' selected="selected"' or ''
             output.append(u'<option value="%s"%s>%s</option>' % (escape(option_value), selected_html, escape(option_label)))
         output.append(u'</select>')
         return u'\n'.join(output)
 
 class SelectMultiple(Widget):
-    pass
+    requires_data_list = True
+    def __init__(self, attrs=None, choices=()):
+        # choices can be any iterable
+        self.attrs = attrs or {}
+        self.choices = choices
+
+    def render(self, name, value, attrs=None, choices=()):
+        if value is None: value = []
+        final_attrs = dict(self.attrs, name=name)
+        if attrs:
+            final_attrs.update(attrs)
+        output = [u'<select multiple="multiple" %s>' % flatatt(final_attrs)]
+        str_values = set([str(v) for v in value]) # Normalize to strings.
+        for option_value, option_label in chain(self.choices, choices):
+            selected_html = (str(option_value) in str_values) and ' selected="selected"' or ''
+            output.append(u'<option value="%s"%s>%s</option>' % (escape(option_value), selected_html, escape(option_label)))
+        output.append(u'</select>')
+        return u'\n'.join(output)
 
 class RadioSelect(Widget):
     pass

tests/regressiontests/forms/tests.py

@@ -236,6 +236,110 @@ If 'choices' is passed to both the constructor and render(), then they'll both b
 <option value="5">5</option>
 </select>
 
+# SelectMultiple Widget #######################################################
+
+>>> w = SelectMultiple()
+>>> print w.render('beatles', ['J'], choices=(('J', 'John'), ('P', 'Paul'), ('G', 'George'), ('R', 'Ringo')))
+<select multiple="multiple" name="beatles">
+<option value="J" selected="selected">John</option>
+<option value="P">Paul</option>
+<option value="G">George</option>
+<option value="R">Ringo</option>
+</select>
+>>> print w.render('beatles', ['J', 'P'], choices=(('J', 'John'), ('P', 'Paul'), ('G', 'George'), ('R', 'Ringo')))
+<select multiple="multiple" name="beatles">
+<option value="J" selected="selected">John</option>
+<option value="P" selected="selected">Paul</option>
+<option value="G">George</option>
+<option value="R">Ringo</option>
+</select>
+>>> print w.render('beatles', ['J', 'P', 'R'], choices=(('J', 'John'), ('P', 'Paul'), ('G', 'George'), ('R', 'Ringo')))
+<select multiple="multiple" name="beatles">
+<option value="J" selected="selected">John</option>
+<option value="P" selected="selected">Paul</option>
+<option value="G">George</option>
+<option value="R" selected="selected">Ringo</option>
+</select>
+
+If the value is None, none of the options are selected:
+>>> print w.render('beatles', None, choices=(('J', 'John'), ('P', 'Paul'), ('G', 'George'), ('R', 'Ringo')))
+<select multiple="multiple" name="beatles">
+<option value="J">John</option>
+<option value="P">Paul</option>
+<option value="G">George</option>
+<option value="R">Ringo</option>
+</select>
+
+If the value corresponds to a label (but not to an option value), none of the options are selected:
+>>> print w.render('beatles', ['John'], choices=(('J', 'John'), ('P', 'Paul'), ('G', 'George'), ('R', 'Ringo')))
+<select multiple="multiple" name="beatles">
+<option value="J">John</option>
+<option value="P">Paul</option>
+<option value="G">George</option>
+<option value="R">Ringo</option>
+</select>
+
+If multiple values are given, but some of them are not valid, the valid ones are selected:
+>>> print w.render('beatles', ['J', 'G', 'foo'], choices=(('J', 'John'), ('P', 'Paul'), ('G', 'George'), ('R', 'Ringo')))
+<select multiple="multiple" name="beatles">
+<option value="J" selected="selected">John</option>
+<option value="P">Paul</option>
+<option value="G" selected="selected">George</option>
+<option value="R">Ringo</option>
+</select>
+
+The value is compared to its str():
+>>> print w.render('nums', [2], choices=[('1', '1'), ('2', '2'), ('3', '3')])
+<select multiple="multiple" name="nums">
+<option value="1">1</option>
+<option value="2" selected="selected">2</option>
+<option value="3">3</option>
+</select>
+>>> print w.render('nums', ['2'], choices=[(1, 1), (2, 2), (3, 3)])
+<select multiple="multiple" name="nums">
+<option value="1">1</option>
+<option value="2" selected="selected">2</option>
+<option value="3">3</option>
+</select>
+>>> print w.render('nums', [2], choices=[(1, 1), (2, 2), (3, 3)])
+<select multiple="multiple" name="nums">
+<option value="1">1</option>
+<option value="2" selected="selected">2</option>
+<option value="3">3</option>
+</select>
+
+The 'choices' argument can be any iterable:
+>>> def get_choices():
+...     for i in range(5):
+...         yield (i, i)
+>>> print w.render('nums', [2], choices=get_choices())
+<select multiple="multiple" name="nums">
+<option value="0">0</option>
+<option value="1">1</option>
+<option value="2" selected="selected">2</option>
+<option value="3">3</option>
+<option value="4">4</option>
+</select>
+
+You can also pass 'choices' to the constructor:
+>>> w = SelectMultiple(choices=[(1, 1), (2, 2), (3, 3)])
+>>> print w.render('nums', [2])
+<select multiple="multiple" name="nums">
+<option value="1">1</option>
+<option value="2" selected="selected">2</option>
+<option value="3">3</option>
+</select>
+
+If 'choices' is passed to both the constructor and render(), then they'll both be in the output:
+>>> print w.render('nums', [2], choices=[(4, 4), (5, 5)])
+<select multiple="multiple" name="nums">
+<option value="1">1</option>
+<option value="2" selected="selected">2</option>
+<option value="3">3</option>
+<option value="4">4</option>
+<option value="5">5</option>
+</select>
+
 # CharField ###################################################################
 
 >>> f = CharField(required=False)