Djangoカスタムフォームフィールドの初期データ

Question

djangoビューでカスタムフォームフィールドを初期化する方法がわかりません。例えば

：上記の例の支払いフォームでhttp://djangosnippets.org/snippets/907/

from datetime import date, datetime 
from calendar import monthrange 

class CreditCardField(forms.IntegerField): 
    @staticmethod 
    def get_cc_type(number): 
     number = str(number) 
     #group checking by ascending length of number 
     if len(number) == 13: 
      if number[0] == "4": 
       return "Visa" 
     return "Unknown" 

    def clean(self, value): 
     if value and (len(value) < 13 or len(value) > 16): 
      raise forms.ValidationError("Please enter in a valid "+\ 
       "credit card number.") 
     elif self.get_cc_type(value) not in ("Visa", "MasterCard", 
              "American Express"): 
      raise forms.ValidationError("Please enter in a Visa, "+\ 
       "Master Card, or American Express credit card number.") 
     return super(CreditCardField, self).clean(value) 

class CCExpWidget(forms.MultiWidget): 
    """ Widget containing two select boxes for selecting the month and year""" 
    def decompress(self, value): 
     return [value.month, value.year] if value else [None, None] 

    def format_output(self, rendered_widgets): 
     html = u'/'.join(rendered_widgets) 
     return u'<span style="white-space: nowrap">%s</span>' % html 


class CCExpField(forms.MultiValueField): 
    EXP_MONTH = [(x, x) for x in xrange(1, 13)] 
    EXP_YEAR = [(x, x) for x in xrange(date.today().year, 
             date.today().year + 15)] 
    default_error_messages = { 
     'invalid_month': u'Enter a valid month.', 
     'invalid_year': u'Enter a valid year.', 
    } 

    def __init__(self, *args, **kwargs): 
     errors = self.default_error_messages.copy() 
     if 'error_messages' in kwargs: 
      errors.update(kwargs['error_messages']) 
     fields = (
      forms.ChoiceField(choices=self.EXP_MONTH, 
       error_messages={'invalid': errors['invalid_month']}), 
      forms.ChoiceField(choices=self.EXP_YEAR, 
       error_messages={'invalid': errors['invalid_year']}), 
     ) 
     super(CCExpField, self).__init__(fields, *args, **kwargs) 
     self.widget = CCExpWidget(widgets = 
      [fields[0].widget, fields[1].widget]) 

    def clean(self, value): 
     exp = super(CCExpField, self).clean(value) 
     if date.today() > exp: 
      raise forms.ValidationError(
      "The expiration date you entered is in the past.") 
     return exp 

    def compress(self, data_list): 
     if data_list: 
      if data_list[1] in forms.fields.EMPTY_VALUES: 
       error = self.error_messages['invalid_year'] 
       raise forms.ValidationError(error) 
      if data_list[0] in forms.fields.EMPTY_VALUES: 
       error = self.error_messages['invalid_month'] 
       raise forms.ValidationError(error) 
      year = int(data_list[1]) 
      month = int(data_list[0]) 
      # find last day of the month 
      day = monthrange(year, month)[1] 
      return date(year, month, day) 
     return None 


class PaymentForm(forms.Form): 
    number = CreditCardField(required = True, label = "Card Number") 
    holder = forms.CharField(required = True, label = "Card Holder Name", 
     max_length = 60) 
    expiration = CCExpField(required = True, label = "Expiration") 
    ccv_number = forms.IntegerField(required = True, label = "CCV Number", 
     max_value = 9999, widget = forms.TextInput(attrs={'size': '4'})) 

    def __init__(self, *args, **kwargs): 
     self.payment_data = kwargs.pop('payment_data', None) 
     super(PaymentForm, self).__init__(*args, **kwargs) 

    def clean(self): 
     cleaned = super(PaymentForm, self).clean() 
     if not self.errors: 
      result = self.process_payment() 
      if result and result[0] == 'Card declined': 
       raise forms.ValidationError('Your credit card was declined.') 
      elif result and result[0] == 'Processing error': 
       raise forms.ValidationError(
        'We encountered the following error while processing '+\ 
        'your credit card: '+result[1]) 
     return cleaned 

    def process_payment(self): 
     if self.payment_data: 
      # don't process payment if payment_data wasn't set 
      datadict = self.cleaned_data 
      datadict.update(self.payment_data) 

      from virtualmerchant import VirtualMerchant 
      vmerchant = VirtualMerchant(datadict) 

      return vmerchant.process_virtualmerchant_payment() 

、どのようにPaymentForm.expirationフィールドに初期データを渡すでしょうか？

私はあなたが行うことができます知っている：

c = PaymentForm({'number':'1234567890', 'holder':'Bob Barker','ccv_number':'123'}) 

はしかし、どのようなここで実装一つとして、カスタムフィールドにデータを渡すのですか？

Answer 1

あなたはそれがカスタムフィールド

https://code.djangoproject.com/browser/django/trunk/django/forms/fields.py#L45

だ場合でもそうあなただけのコンストラクタを上書きすることができるはずという設定ので、すべてのフィールドが「初期」属性を持っている：

class PaymentForm(forms.Form): 
    def __init__(self, exp = None, *args, **kwargs): 
     super(PaymentForm, self).__init__(*args, **kwargs) 
     if exp: 
      self.fields['expiration'].initial = exp 

とあなたの見解では、必要なデータを渡すことができます：

form = PaymentForm(exp=...)