Django的自定義字段保存，但沒有想象

Question

我創建了一個字段保存平日裏，在這樣一個模型中使用（models.py）：

from myfields import * 
from django.db import models 

class MyModel(models.Model): 
    weekdays = WeekdayField() 

在我所存儲的形式申報的文件是myfields.py是這一個：

from django.db import models 
from django import forms 

class Weekdays(object): 
    CHOICES = (
     (1, "Monday"), 
     (2, "Tuesday"), 
     (4, "Wednesday"), 
     (8, "Thursday"), 
     (16, "Friday"), 
     (32, "Saturday"), 
     (64, "Sunday"), 
     ) 
    MONDAY,TUESDAY,WEDNESDAY,THURSDAY,FRIDAY,SATURDAY,SUNDAY = [2**i for i in range(0,7)] 
    del i 

    def __init__(self, value=0): 
     self.raw = value 

    def __add__(self, other): 
     return Weekdays(self.raw | other) 

    def __sub__(self, other): 
     return Weekdays(self.raw & (-1^other)) 

    def __unicode__(self): 
     ret = [] 
     for ele in Weekdays.CHOICES: 
      if (self.raw & ele[0]) >> ele[0] == 1: 
       ret.append(ele[1]) 
     return ",".join(ret) 

    def __iter__(self): 
     ret = [] 
     for ele in Weekdays.CHOICES: 
      if (self.raw & ele[0]) >> ele[0] == 1: 
       ret.append(ele) 
     return iter(ret) 

    def __len__(self): 
     i = 0 
     for n in range(7): 
      if (self.raw & n) >> n == 1: 
       i += 1 
     return i 



class WeekdayField(models.Field): 
    description = "Multiple select of weekdays" 

    __metaclass__ = models.SubfieldBase 

    def __init__(self, *args, **kwargs): 
     kwargs['max_length'] = 3 
     super(WeekdayField, self).__init__(*args, **kwargs) 

    def to_python(self, value): 
     if isinstance(value, int): 
      return [ wd for wd in Weekdays(value) ] 
     if isinstance(value, Weekdays): 
      return value 
     if isinstance(value, list): #list of weekstay 
      wd = Weekdays() 
      for val in value: 
       wd += int(val) 
      return wd 

    # PY to DB 
    def get_prep_value(self, value): 
     return value.raw 

    def formfield(self, **kwargs): 
     defaults = {'form_class': WeekdayFormField} 
     defaults.update(kwargs) 
     return super(WeekdayField, self).formfield(**defaults) 

    def get_internal_type(self): 
     return "IntegerField" 


class WeekdayFormField(forms.MultipleChoiceField): 
    def __init__(self, *args, **kwargs): 
     if 'choices' not in kwargs: 
      kwargs['choices'] = Weekdays.CHOICES 
     kwargs.pop('max_length', None) 
     if 'widget' not in kwargs: 
      kwargs['widget'] = forms.widgets.CheckboxSelectMultiple 
     super(WeekdayFormField, self).__init__(*args, **kwargs) 


    def clean(self, value): 
     super(WeekdayFormField, self).clean(value) 
     possible_values = [ str(x[0]) for x in Weekdays.CHOICES ] 
     for v in value: 
      if not v in possible_values: 
       raise forms.ValidationError("Day not valid") 
     return value 

使用這個我可以創建和刪除通過Django管理的元素，但是當我修改的值我沒有看到，我以前存儲的值。我查看了數據庫，並且該值存儲正確。

關於如何在修改期間讓我看看Django Admin上的當前值是什麼？

Answer 1

我有解決方案！實施方法Weekdays.__unicode__()和Weekdays.__iter__()是錯誤的。

最後我還改變了下面報告的兩種方法，在WeekdayField。

#Class-type 
class Weekdays(object): 
    ... 

    def __unicode__(self): # Request for the matching 
     ret = [] 
     for i,ele in enumerate(Weekdays.CHOICES): 
      if (self.raw & ele[0]) >> i == 1: 
       ret.append(unicode(ele[0])) 
     return ','.join(ret) 

    def __iter__(self): 
     for i,ele in enumerate(Weekdays.CHOICES): 
      if (self.raw & ele[0]) >> i == 1: 
       yield Weekdays(ele[0]) 


#Field to include in the model 
class WeekdayField(models.Field): 
    ... 

    # DB to PY 
    def to_python(self, value): 
     if isinstance(value, int): 
      return [ wd for wd in Weekdays(value) ] 
     if isinstance(value, unicode): 
      return [ wd for wd in Weekdays(int(value)) ] 
     if isinstance(value, Weekdays): 
      return value 
     if isinstance(value, list): #list of Weekdays 
      wd = [] 
      for val in value: 
       wd += self.to_python(val) 
      return wd 

    #PY to DB 
    def get_prep_value(self, value): 
     if isinstance(value, Weekdays): 
      return value.raw 
     if isinstance(value, list): 
      sum_raw = 0 
      for val in value: 
       sum_raw += self.get_prep_value(val) 
      return sum_raw 

我希望這會對某人有所幫助！