lp.app.widgets.date.DateWidget : API documentation

A date selection widget with popup selector.

The assumed underlying storage is a datetime (in the database) so this class modifies that datetime into a date for presentation purposes. That date is always in UTC.

The DateWidget subclass can limit requests to date ranges:

>>> from zope.publisher.browser import TestRequest
>>> from zope.schema import Field
>>> from datetime import date
>>> field = Field(__name__='foo', title=u'Foo')
>>> from_date = date(2004, 4, 5)
>>> to_date = date(2004, 4, 10)
>>> widget = DateWidget(field, TestRequest())
>>> widget.from_date = from_date
>>> widget.to_date = to_date
>>> '[[2004,04,05],[2004,04,10]]' in widget()
True

This widget ignores required_time_zone and system_time_zone and interprets everything as UTC. This does not matter, because it is only picking the date, and it will always be rendered as a date sans time zone even if it is stored as a datetime.

>>> widget.time_zone
<UTC>

>>> widget.system_time_zone = pytz.timezone('America/New_York')
>>> widget.time_zone
<UTC>

>>> widget.required_time_zone = pytz.timezone('America/Los_Angeles')
>>> widget.time_zone
<UTC>

A date picker can be disabled initially:

>>> 'disabled' in widget()
False
>>> widget.disabled = True
>>> 'disabled' in widget()
True

Method	setRenderedValue	Render a date from the underlying datetime.
Method	_toFieldValue	Return parsed input (datetime) as a date.
Method	_toFormValue	Convert a datetime to its string representation.

Inherited from DateTimeWidget:

Method	__init__	Undocumented
Method	supported_input_formats	Undocumented
Method	time_zone	The widget time zone.
Method	time_zone_name	The name of the widget time zone for display in the widget.
Method	disabled_flag	Return a string to make the form input disabled if necessary.
Method	daterange	The javascript variable giving the allowed date range to pick.
Method	getInputValue	Return the date, if it is in the allowed date range.
Method	formvalue	Return the value for the form to render, accessed via the
Method	_align_date_constraints_with_time_zone	Ensure that from_date and to_date use the widget time zone.
Method	_checkSupportedFormat	Checks that the input is in a usable format.
Method	_parseInput	Convert a string to a datetime value.

def _toFieldValue(self, input):

overrides lp.app.widgets.date.DateTimeWidget._toFieldValue

Return parsed input (datetime) as a date.

The input is expected to be a text string in a format that datetime can parse. The input is parsed by the DateTimeWidget._parseInput method, which returns a datetime, and this method turns that into a date (without the time).

>>> from zope.publisher.browser import TestRequest
>>> from zope.schema import Field
>>> field = Field(__name__='foo', title=u'Foo')
>>> widget = DateWidget(field, TestRequest())

The widget converts an empty string to the missing value:

>>> widget._toFieldValue('') == field.missing_value
True

The widget ignores time and time zone information, returning only the date:

>>> print widget._toFieldValue('2006-01-01 12:00:00')
2006-01-01

Even if you feed it information that gives a time zone, it will ignore that:

>>> print widget._toFieldValue('2006-01-01 2:00:00+06:00')
2006-01-01
>>> print widget._toFieldValue('2006-01-01 23:00:00-06:00')
2006-01-01

Invalid dates result in a ConversionError:

>>> print widget._toFieldValue('not a date')  #doctest: +ELLIPSIS
Traceback (most recent call last):
  ...
ConversionError: ('Invalid date value', ...)

def _toFormValue(self, value):

overrides lp.app.widgets.date.DateTimeWidget._toFormValue

Convert a datetime to its string representation.

>>> from zope.publisher.browser import TestRequest
>>> from zope.schema import Field
>>> field = Field(__name__='foo', title=u'Foo')
>>> widget = DateWidget(field, TestRequest())

The 'missing' value is converted to an empty string:

>>> widget._toFormValue(field.missing_value)
u''

The widget ignores time and time zone information, returning only the date:

>>> dt = datetime(
...     2006, 1, 1, 12, 0, 0, tzinfo=pytz.timezone('UTC'))
>>> widget._toFormValue(dt)
'2006-01-01'

The widget can handle a date just as well as a datetime, of course.

>>> a_date = dt.date()
>>> widget._toFormValue(a_date)
'2006-01-01'

l.a.w.d.DateWidget(DateTimeWidget) : class documentation