Ticket #16575: widgets.py

"""
Extra HTML Widget classes
"""

import time
import datetime
import re

from django.forms.widgets import Widget, Select
from django.utils import datetime_safe
from django.utils.dates import MONTHS
from django.utils.safestring import mark_safe
from django.utils.formats import get_format
from django.conf import settings

__all__ = ('SelectDateWidget',)

RE_DATE = re.compile(r'(\d{4})-(\d\d?)-(\d\d?)$')

def _parse_format(fmt):
        def pos(s):
                match = re.search('[' + s + ']', fmt)
                return match.start() + 1 if match else 0
        
        dic = {'day': pos('dj'), 'month': pos('bEFMmNn'), 'year': pos('yY')}
        return sorted(filter(None, dic.keys()), key=dic.get)

def _parse_date_fmt():
        return _parse_format(re.subn(r'\\.', '', get_format('DATE_FORMAT'))[0])


class SelectDateWidget(Widget):
        """
        A Widget that splits date input into three <select> boxes.

        This also serves as an example of a Widget that has more than one HTML
        element and hence implements value_from_datadict.
        """
        names = ('day', 'month', 'year',)
        none_values_dafault = '---'
        field_values = ['%s_' + n for n in names]
        fields = dict(zip(names, field_values))
        day_field, month_field, year_field = field_values

        def __init__(self, attrs=None, years=None, required=True,
                        date_format='', none_values=None):
                # years is an optional list/tuple of years
                # to use in the "year" select box.
                self.attrs = attrs or {}
                self.required = required
                if not years:
                        this_year = datetime.date.today().year
                        years = range(this_year, this_year+10)
                print list(years)
                self.years = years
                self.date_format = _parse_format(date_format)
                self.none_values = none_values \
                        or dict([(i, self.none_values_dafault) for i in 'dmy'])

        def render(self, name, value, attrs=None):
                
                get_names_dict = lambda l: dict(zip(self.names, l))
                
                try:
                        values_list = [getattr(value, n) for n in self.names]
                except AttributeError:
                        values_list = []
                        if isinstance(value, basestring):
                                if settings.USE_L10N:
                                        try:
                                                input_format = get_format('DATE_INPUT_FORMATS')[0]
                                                v = datetime.datetime.strptime(value, input_format)
                                                values_list = [getattr(v, n) for n in self.names]
                                        except ValueError:
                                                pass
                                else:
                                        match = RE_DATE.match(value)
                                        if match:
                                                values_list = (int(v) for v in match.groups())
                values = get_names_dict(values_list)
                
                choices = get_names_dict([
                        [(i, i) for i in range(1, 32)],
                        MONTHS.items(),
                        [(i, i) for i in self.years],
                ])
                
                create_select_short = lambda n: self.create_select(
                        name, self.fields[n], value, values.get(n), choices[n], n
                )
                
                htmls = get_names_dict([create_select_short(n) for n in self.names])
                
                date_format = self.date_format or _parse_date_fmt()
                output = [htmls[field] for field in date_format]
                return mark_safe(u'\n'.join(output))

        def id_for_label(cls, id_):
                field_list = _parse_date_fmt()
                if field_list:
                        first_select = field_list[0]
                else:
                        first_select = 'month'
                return '%s_%s' % (id_, first_select)
        id_for_label = classmethod(id_for_label)

        def value_from_datadict(self, data, files, name):
                d, m, y = (data.get(self.fields[n] % name) for n in self.names)
                if y == m == d == "0":
                        return None
                if not (y and m and d):
                        return data.get(name)
                if not settings.USE_L10N:
                        return '%s-%s-%s' % (y, m, d)
                input_format = get_format('DATE_INPUT_FORMATS')[0]
                try:
                        date_value = datetime.date(int(y), int(m), int(d))
                        date_value = datetime_safe.new_date(date_value)
                        return date_value.strftime(input_format)
                except ValueError:
                        return '%s-%s-%s' % (y, m, d)

        def create_select(self, name, field, value, val, choices, date_part='d'):
                if 'id' in self.attrs:
                        id_ = self.attrs['id']
                else:
                        id_ = 'id_%s' % name
                if not (self.required and val):
                        choices.insert(0, (0, self.none_values[date_part[0]]))
                local_attrs = self.build_attrs(id=field % id_)
                s = Select(choices=choices)
                select_html = s.render(field % name, val, local_attrs)
                return select_html