Third-party packages that do not need to be part of trunk/app (because they are
not part of a Google App Engine image upload).
"""
HTML Widget classes
"""
try:
set
except NameError:
from sets import Set as set # Python 2.3 fallback
import copy
from itertools import chain
from django.utils.datastructures import MultiValueDict
from django.utils.html import escape, conditional_escape
from django.utils.translation import ugettext
from django.utils.encoding import StrAndUnicode, force_unicode
from django.utils.safestring import mark_safe
from util import flatatt
__all__ = (
'Widget', 'TextInput', 'PasswordInput',
'HiddenInput', 'MultipleHiddenInput',
'FileInput', 'DateTimeInput', 'Textarea', 'CheckboxInput',
'Select', 'NullBooleanSelect', 'SelectMultiple', 'RadioSelect',
'CheckboxSelectMultiple', 'MultiWidget', 'SplitDateTimeWidget',
)
class Widget(object):
is_hidden = False # Determines whether this corresponds to an <input type="hidden">.
needs_multipart_form = False # Determines does this widget need multipart-encrypted form
def __init__(self, attrs=None):
if attrs is not None:
self.attrs = attrs.copy()
else:
self.attrs = {}
def __deepcopy__(self, memo):
obj = copy.copy(self)
obj.attrs = self.attrs.copy()
memo[id(self)] = obj
return obj
def render(self, name, value, attrs=None):
"""
Returns this Widget rendered as HTML, as a Unicode string.
The 'value' given is not guaranteed to be valid input, so subclass
implementations should program defensively.
"""
raise NotImplementedError
def build_attrs(self, extra_attrs=None, **kwargs):
"Helper function for building an attribute dictionary."
attrs = dict(self.attrs, **kwargs)
if extra_attrs:
attrs.update(extra_attrs)
return attrs
def value_from_datadict(self, data, files, name):
"""
Given a dictionary of data and this widget's name, returns the value
of this widget. Returns None if it's not provided.
"""
return data.get(name, None)
def id_for_label(self, id_):
"""
Returns the HTML ID attribute of this Widget for use by a <label>,
given the ID of the field. Returns None if no ID is available.
This hook is necessary because some widgets have multiple HTML
elements and, thus, multiple IDs. In that case, this method should
return an ID value that corresponds to the first ID in the widget's
tags.
"""
return id_
id_for_label = classmethod(id_for_label)
class Input(Widget):
"""
Base class for all <input> widgets (except type='checkbox' and
type='radio', which are special).
"""
input_type = None # Subclasses must define this.
def render(self, name, value, attrs=None):
if value is None: value = ''
final_attrs = self.build_attrs(attrs, type=self.input_type, name=name)
if value != '':
# Only add the 'value' attribute if a value is non-empty.
final_attrs['value'] = force_unicode(value)
return mark_safe(u'<input%s />' % flatatt(final_attrs))
class TextInput(Input):
input_type = 'text'
class PasswordInput(Input):
input_type = 'password'
def __init__(self, attrs=None, render_value=True):
super(PasswordInput, self).__init__(attrs)
self.render_value = render_value
def render(self, name, value, attrs=None):
if not self.render_value: value=None
return super(PasswordInput, self).render(name, value, attrs)
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 __init__(self, attrs=None, choices=()):
super(MultipleHiddenInput, self).__init__(attrs)
# choices can be any iterable
self.choices = choices
def render(self, name, value, attrs=None, choices=()):
if value is None: value = []
final_attrs = self.build_attrs(attrs, type=self.input_type, name=name)
return mark_safe(u'\n'.join([(u'<input%s />' %
flatatt(dict(value=force_unicode(v), **final_attrs)))
for v in value]))
def value_from_datadict(self, data, files, name):
if isinstance(data, MultiValueDict):
return data.getlist(name)
return data.get(name, None)
class FileInput(Input):
input_type = 'file'
needs_multipart_form = True
def render(self, name, value, attrs=None):
return super(FileInput, self).render(name, None, attrs=attrs)
def value_from_datadict(self, data, files, name):
"File widgets take data from FILES, not POST"
return files.get(name, None)
class Textarea(Widget):
def __init__(self, attrs=None):
# The 'rows' and 'cols' attributes are required for HTML correctness.
self.attrs = {'cols': '40', 'rows': '10'}
if attrs:
self.attrs.update(attrs)
def render(self, name, value, attrs=None):
if value is None: value = ''
value = force_unicode(value)
final_attrs = self.build_attrs(attrs, name=name)
return mark_safe(u'<textarea%s>%s</textarea>' % (flatatt(final_attrs),
conditional_escape(force_unicode(value))))
class DateTimeInput(Input):
input_type = 'text'
format = '%Y-%m-%d %H:%M:%S' # '2006-10-25 14:30:59'
def __init__(self, attrs=None, format=None):
super(DateTimeInput, self).__init__(attrs)
if format:
self.format = format
def render(self, name, value, attrs=None):
if value is None:
value = ''
elif hasattr(value, 'strftime'):
value = value.strftime(self.format)
return super(DateTimeInput, self).render(name, value, attrs)
class CheckboxInput(Widget):
def __init__(self, attrs=None, check_test=bool):
super(CheckboxInput, self).__init__(attrs)
# check_test is a callable that takes a value and returns True
# if the checkbox should be checked for that value.
self.check_test = check_test
def render(self, name, value, attrs=None):
final_attrs = self.build_attrs(attrs, type='checkbox', name=name)
try:
result = self.check_test(value)
except: # Silently catch exceptions
result = False
if result:
final_attrs['checked'] = 'checked'
if value not in ('', True, False, None):
# Only add the 'value' attribute if a value is non-empty.
final_attrs['value'] = force_unicode(value)
return mark_safe(u'<input%s />' % flatatt(final_attrs))
def value_from_datadict(self, data, files, name):
if name not in data:
# A missing value means False because HTML form submission does not
# send results for unselected checkboxes.
return False
return super(CheckboxInput, self).value_from_datadict(data, files, name)
class Select(Widget):
def __init__(self, attrs=None, choices=()):
super(Select, self).__init__(attrs)
# choices can be any iterable, but we may need to render this widget
# multiple times. Thus, collapse it into a list so it can be consumed
# more than once.
self.choices = list(choices)
def render(self, name, value, attrs=None, choices=()):
if value is None: value = ''
final_attrs = self.build_attrs(attrs, name=name)
output = [u'<select%s>' % flatatt(final_attrs)]
# Normalize to string.
str_value = force_unicode(value)
for option_value, option_label in chain(self.choices, choices):
option_value = force_unicode(option_value)
selected_html = (option_value == str_value) and u' selected="selected"' or ''
output.append(u'<option value="%s"%s>%s</option>' % (
escape(option_value), selected_html,
conditional_escape(force_unicode(option_label))))
output.append(u'</select>')
return mark_safe(u'\n'.join(output))
class NullBooleanSelect(Select):
"""
A Select Widget intended to be used with NullBooleanField.
"""
def __init__(self, attrs=None):
choices = ((u'1', ugettext('Unknown')), (u'2', ugettext('Yes')), (u'3', ugettext('No')))
super(NullBooleanSelect, self).__init__(attrs, choices)
def render(self, name, value, attrs=None, choices=()):
try:
value = {True: u'2', False: u'3', u'2': u'2', u'3': u'3'}[value]
except KeyError:
value = u'1'
return super(NullBooleanSelect, self).render(name, value, attrs, choices)
def value_from_datadict(self, data, files, name):
value = data.get(name, None)
return {u'2': True, u'3': False, True: True, False: False}.get(value, None)
class SelectMultiple(Widget):
def __init__(self, attrs=None, choices=()):
super(SelectMultiple, self).__init__(attrs)
# choices can be any iterable
self.choices = choices
def render(self, name, value, attrs=None, choices=()):
if value is None: value = []
final_attrs = self.build_attrs(attrs, name=name)
output = [u'<select multiple="multiple"%s>' % flatatt(final_attrs)]
str_values = set([force_unicode(v) for v in value]) # Normalize to strings.
for option_value, option_label in chain(self.choices, choices):
option_value = force_unicode(option_value)
selected_html = (option_value in str_values) and ' selected="selected"' or ''
output.append(u'<option value="%s"%s>%s</option>' % (
escape(option_value), selected_html,
conditional_escape(force_unicode(option_label))))
output.append(u'</select>')
return mark_safe(u'\n'.join(output))
def value_from_datadict(self, data, files, name):
if isinstance(data, MultiValueDict):
return data.getlist(name)
return data.get(name, None)
class RadioInput(StrAndUnicode):
"""
An object used by RadioFieldRenderer that represents a single
<input type='radio'>.
"""
def __init__(self, name, value, attrs, choice, index):
self.name, self.value = name, value
self.attrs = attrs
self.choice_value = force_unicode(choice[0])
self.choice_label = force_unicode(choice[1])
self.index = index
def __unicode__(self):
return mark_safe(u'<label>%s %s</label>' % (self.tag(),
conditional_escape(force_unicode(self.choice_label))))
def is_checked(self):
return self.value == self.choice_value
def tag(self):
if 'id' in self.attrs:
self.attrs['id'] = '%s_%s' % (self.attrs['id'], self.index)
final_attrs = dict(self.attrs, type='radio', name=self.name, value=self.choice_value)
if self.is_checked():
final_attrs['checked'] = 'checked'
return mark_safe(u'<input%s />' % flatatt(final_attrs))
class RadioFieldRenderer(StrAndUnicode):
"""
An object used by RadioSelect to enable customization of radio widgets.
"""
def __init__(self, name, value, attrs, choices):
self.name, self.value, self.attrs = name, value, attrs
self.choices = choices
def __iter__(self):
for i, choice in enumerate(self.choices):
yield RadioInput(self.name, self.value, self.attrs.copy(), choice, i)
def __getitem__(self, idx):
choice = self.choices[idx] # Let the IndexError propogate
return RadioInput(self.name, self.value, self.attrs.copy(), choice, idx)
def __unicode__(self):
return self.render()
def render(self):
"""Outputs a <ul> for this set of radio fields."""
return mark_safe(u'<ul>\n%s\n</ul>' % u'\n'.join([u'<li>%s</li>'
% force_unicode(w) for w in self]))
class RadioSelect(Select):
renderer = RadioFieldRenderer
def __init__(self, *args, **kwargs):
# Override the default renderer if we were passed one.
renderer = kwargs.pop('renderer', None)
if renderer:
self.renderer = renderer
super(RadioSelect, self).__init__(*args, **kwargs)
def get_renderer(self, name, value, attrs=None, choices=()):
"""Returns an instance of the renderer."""
if value is None: value = ''
str_value = force_unicode(value) # Normalize to string.
final_attrs = self.build_attrs(attrs)
choices = list(chain(self.choices, choices))
return self.renderer(name, str_value, final_attrs, choices)
def render(self, name, value, attrs=None, choices=()):
return self.get_renderer(name, value, attrs, choices).render()
def id_for_label(self, id_):
# RadioSelect is represented by multiple <input type="radio"> fields,
# each of which has a distinct ID. The IDs are made distinct by a "_X"
# suffix, where X is the zero-based index of the radio field. Thus,
# the label for a RadioSelect should reference the first one ('_0').
if id_:
id_ += '_0'
return id_
id_for_label = classmethod(id_for_label)
class CheckboxSelectMultiple(SelectMultiple):
def render(self, name, value, attrs=None, choices=()):
if value is None: value = []
has_id = attrs and 'id' in attrs
final_attrs = self.build_attrs(attrs, name=name)
output = [u'<ul>']
# Normalize to strings
str_values = set([force_unicode(v) for v in value])
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 = force_unicode(option_value)
rendered_cb = cb.render(name, option_value)
output.append(u'<li><label>%s %s</label></li>' % (rendered_cb,
conditional_escape(force_unicode(option_label))))
output.append(u'</ul>')
return mark_safe(u'\n'.join(output))
def id_for_label(self, id_):
# See the comment for RadioSelect.id_for_label()
if id_:
id_ += '_0'
return id_
id_for_label = classmethod(id_for_label)
class MultiWidget(Widget):
"""
A widget that is composed of multiple widgets.
Its render() method is different than other widgets', because it has to
figure out how to split a single value for display in multiple widgets.
The ``value`` argument can be one of two things:
* A list.
* A normal value (e.g., a string) that has been "compressed" from
a list of values.
In the second case -- i.e., if the value is NOT a list -- render() will
first "decompress" the value into a list before rendering it. It does so by
calling the decompress() method, which MultiWidget subclasses must
implement. This method takes a single "compressed" value and returns a
list.
When render() does its HTML rendering, each value in the list is rendered
with the corresponding widget -- the first value is rendered in the first
widget, the second value is rendered in the second widget, etc.
Subclasses may implement format_output(), which takes the list of rendered
widgets and returns a string of HTML that formats them any way you'd like.
You'll probably want to use this class with MultiValueField.
"""
def __init__(self, widgets, attrs=None):
self.widgets = [isinstance(w, type) and w() or w for w in widgets]
super(MultiWidget, self).__init__(attrs)
def render(self, name, value, attrs=None):
# value is a list of values, each corresponding to a widget
# in self.widgets.
if not isinstance(value, list):
value = self.decompress(value)
output = []
final_attrs = self.build_attrs(attrs)
id_ = final_attrs.get('id', None)
for i, widget in enumerate(self.widgets):
try:
widget_value = value[i]
except IndexError:
widget_value = None
if id_:
final_attrs = dict(final_attrs, id='%s_%s' % (id_, i))
output.append(widget.render(name + '_%s' % i, widget_value, final_attrs))
return mark_safe(self.format_output(output))
def id_for_label(self, id_):
# See the comment for RadioSelect.id_for_label()
if id_:
id_ += '_0'
return id_
id_for_label = classmethod(id_for_label)
def value_from_datadict(self, data, files, name):
return [widget.value_from_datadict(data, files, name + '_%s' % i) for i, widget in enumerate(self.widgets)]
def format_output(self, rendered_widgets):
"""
Given a list of rendered widgets (as strings), returns a Unicode string
representing the HTML for the whole lot.
This hook allows you to format the HTML design of the widgets, if
needed.
"""
return u''.join(rendered_widgets)
def decompress(self, value):
"""
Returns a list of decompressed values for the given compressed value.
The given value can be assumed to be valid, but not necessarily
non-empty.
"""
raise NotImplementedError('Subclasses must implement this method.')
class SplitDateTimeWidget(MultiWidget):
"""
A Widget that splits datetime input into two <input type="text"> boxes.
"""
def __init__(self, attrs=None):
widgets = (TextInput(attrs=attrs), TextInput(attrs=attrs))
super(SplitDateTimeWidget, self).__init__(widgets, attrs)
def decompress(self, value):
if value:
return [value.date(), value.time().replace(microsecond=0)]
return [None, None]