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1 """ |
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2 South Africa-specific Form helpers |
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3 """ |
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4 |
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5 from django.forms import ValidationError |
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6 from django.forms.fields import Field, RegexField, EMPTY_VALUES |
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7 from django.utils.checksums import luhn |
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8 from django.utils.translation import gettext as _ |
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9 import re |
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10 from datetime import date |
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11 |
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12 id_re = re.compile(r'^(?P<yy>\d\d)(?P<mm>\d\d)(?P<dd>\d\d)(?P<mid>\d{4})(?P<end>\d{3})') |
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13 |
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14 class ZAIDField(Field): |
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15 """A form field for South African ID numbers -- the checksum is validated |
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16 using the Luhn checksum, and uses a simlistic (read: not entirely accurate) |
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17 check for the birthdate |
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18 """ |
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19 default_error_messages = { |
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20 'invalid': _(u'Enter a valid South African ID number'), |
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21 } |
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22 |
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23 def clean(self, value): |
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24 # strip spaces and dashes |
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25 value = value.strip().replace(' ', '').replace('-', '') |
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26 |
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27 super(ZAIDField, self).clean(value) |
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28 |
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29 if value in EMPTY_VALUES: |
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30 return u'' |
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31 |
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32 match = re.match(id_re, value) |
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33 |
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34 if not match: |
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35 raise ValidationError(self.error_messages['invalid']) |
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36 |
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37 g = match.groupdict() |
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38 |
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39 try: |
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40 # The year 2000 is conveniently a leapyear. |
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41 # This algorithm will break in xx00 years which aren't leap years |
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42 # There is no way to guess the century of a ZA ID number |
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43 d = date(int(g['yy']) + 2000, int(g['mm']), int(g['dd'])) |
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44 except ValueError: |
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45 raise ValidationError(self.error_messages['invalid']) |
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46 |
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47 if not luhn(value): |
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48 raise ValidationError(self.error_messages['invalid']) |
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49 |
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50 return value |
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51 |
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52 class ZAPostCodeField(RegexField): |
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53 default_error_messages = { |
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54 'invalid': _(u'Enter a valid South African postal code'), |
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55 } |
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56 |
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57 def __init__(self, *args, **kwargs): |
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58 super(ZAPostCodeField, self).__init__(r'^\d{4}$', |
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59 max_length=None, min_length=None) |