Date Range widget and field.

date_range.py

# -*- coding: utf-8 -*-

#
# This code have contributions of Augusto Men (https://github.com/augustomen)
# and Nando Florestan (https://github.com/nandoflorestan)
#

from __future__ import (absolute_import, division, unicode_literals)

from datetime import date
from django.core.exceptions import ValidationError
from django.forms.fields import (DateField, MultiValueField)
from django.forms.util import flatatt
from django.forms.widgets import (MultiWidget, DateInput)
from django.utils.safestring import mark_safe


class DateInput5(DateInput):
    """
    Renders a bootstrap + jquery date input.
    """

    # input_type = "date" isn't yet fully supported except by webkit and opera.
    # also, inputs type date can't have datepicker customized, so we use
    # input type=text and jquery datepicker
    input_type = 'text'

    def render(self, name, value, attrs=None):
        final = {'class': "input-small", 'placeholder': "dia/mês/ano"}
        if attrs:
            final.update(attrs)
        tag = super(DateInput5, self).render(name, value, final)
        return mark_safe('<div class="input-append datepicker">'
            + tag + '''<button class="btn"
            type="button"><i class="icon-calendar"></i></button>
        </div>''')


class DateField5(DateField):
    """
    Represents a date input with bootstrap css and jquery date picker

    TODO: put it in field media
  <script src="{% static "js/jquery-ui/js/jquery-ui-1.8.22.custom.min.js" %}"
    type="text/javascript"></script>
  <script src="{% static "js/jquery-ui/js/jquery.ui.datepicker-pt-BR.js" %}"
    type="text/javascript"></script>

    Need that :)

    """
    def __init__(self, placeholder=None, autofocus=None, **kw):
        self.placeholder = placeholder
        self.autofocus = autofocus
        super(DateField5, self).__init__(**kw)

    def widget_attrs(self, widget):
        attrs = super(DateField5, self).widget_attrs(widget)
        attrs['placeholder'] = self.placeholder
        if self.autofocus:
            attrs['autofocus'] = 'autofocus'
        if self.required:
            attrs['required'] = 'required'
        # TODO: if using type=date, support date ranges, check w3c html5 ref.
        # if self.min_value:
        #     attrs['min'] = self.min_value
        # if self.max_value:
        #     attrs['max'] = self.max_value
        return attrs


class DateRangeInput(MultiWidget):
    """
    Render a filter with start date and end date using bootstrap and jquery.
    """
    def __init__(self, till_today=True, attrs=None):
        """
        The *till_today* flag configures what happens when the second date
        is blank. If true, the application receives today's date; if false,
        a ValidationError is raised. True is the default.
        """
        self.till_today = till_today
        # TODO: i18n
        end = dict(title='Se em branco, é considerada a data de hoje.') \
            if till_today else None
        widget = (DateInput5(), DateInput5(attrs=end),)
        super(DateRangeInput, self).__init__(widget, attrs=attrs)

    def decompress(self, value):
        """
        Called when rendering the widget.
        """
        return value or (None, None)

    def format_output(self, rendered_widgets):
        return mark_safe('\n&nbsp; a &nbsp;\n'.join(rendered_widgets))


class DateRangeField(MultiValueField):
    """ Represents a filter with start date and end date. """
    widget = DateRangeInput

    def __init__(self, input_formats=None, **kwargs):
        localize = kwargs.get('localize', False)
        fields = (
            DateField5(input_formats=input_formats,
                       localize=localize,
                       **kwargs),
            DateField5(input_formats=input_formats,
                       localize=localize,
                       **kwargs)
        )
        super(DateRangeField, self).__init__(fields, **kwargs)

    def compress(self, data_list):
        """
        Gets and returns something like [None, datetime.date(2012, 8, 1)].

        Checks that either both values are present, or none.
        Also ensures the values make sense in relation to each other.
        """
        if not data_list or (not data_list[0] and not data_list[1]):
            return None, None
        elif not data_list[0]:
            # TODO: i18n
            raise ValidationError('Falta preencher a data inicial.')
        elif not data_list[1]:
            if hasattr(self.widget, 'till_today') and self.widget.till_today:
                data_list[1] = date.today()
            else:
                # TODO: i18n
                raise ValidationError('Falta preencher a data final.')
        elif data_list[0] > data_list[1]:
            # TODO: i18n
            raise ValidationError('A data inicial está posterior à final.')
        return data_list