Вы можете посмотреть на реализацию поля даты и времени, которое отображается как 2 поля в админке.
Идет сверху вниз,
Администратор использует
class AdminSplitDateTime(forms.SplitDateTimeWidget):
"""
A SplitDateTime Widget that has some admin-specific styling.
"""
def __init__(self, attrs=None):
widgets = [AdminDateWidget, AdminTimeWidget]
# Note that we're calling MultiWidget, not SplitDateTimeWidget, because
# we want to define widgets.
forms.MultiWidget.__init__(self, widgets, attrs)
def format_output(self, rendered_widgets):
return mark_safe(u'<p class="datetime">%s %s<br />%s %s</p>' % \
(_('Date:'), rendered_widgets[0], _('Time:'), rendered_widgets[1]))
, который в свою очередь использует SplitDateTimeWidget:
class SplitDateTimeWidget(MultiWidget):
"""
A Widget that splits datetime input into two <input type="text"> boxes.
"""
date_format = DateInput.format
time_format = TimeInput.format
def __init__(self, attrs=None, date_format=None, time_format=None):
if date_format:
self.date_format = date_format
if time_format:
self.time_format = time_format
widgets = (DateInput(attrs=attrs, format=self.date_format),
TimeInput(attrs=attrs, format=self.time_format))
super(SplitDateTimeWidget, self).__init__(widgets, attrs)
def decompress(self, value):
if value:
return [value.date(), value.time().replace(microsecond=0)]
return [None, None]
Что в свою очередь расширяет MultiWidget, определенный в django.forms.widgets, который вы также должны расширять. У него есть много полезных методов, которые вы можете переопределить.
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 _has_changed(self, initial, data):
if initial is None:
initial = [u'' for x in range(0, len(data))]
else:
if not isinstance(initial, list):
initial = self.decompress(initial)
for widget, initial, data in zip(self.widgets, initial, data):
if widget._has_changed(initial, data):
return True
return False
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.')
def _get_media(self):
"Media for a multiwidget is the combination of all media of the subwidgets"
media = Media()
for w in self.widgets:
media = media + w.media
return media
media = property(_get_media)
def __deepcopy__(self, memo):
obj = super(MultiWidget, self).__deepcopy__(memo)
obj.widgets = copy.deepcopy(self.widgets)
return obj