python - Django 模型中的动态选择字段

Question

我的模型.py:

SHOP1_CHOICES = (
    ('Food Court', 'Food Court'),
    ('KFC', 'KFC'),

)

SHOP2_CHOICES = (
    ('Sports Arena', 'Sports Arena'),
    ('Disco D', 'Disco D'),

)

SHOP3_CHOICES = (
    ('Bowling Arena', 'Bowling Arena'),
    ('Cinemax', 'Cinemax'),

)

class Feed(models.Model):
  gender = models.CharField(max_length=5, choices=GENDER_CHOICES, default='girl')
  name =models.CharField(max_length=25)
  shop=models.CharField(max_length=20)
  location=models.CharField(max_length=25, choices=SHOP1_CHOICES)

如果 Feed.shop == 'shop1' 我想在 Feed.location 上加载 SHOP1_CHOICES。目前不管是什么店，它都只显示SHOP1_CHOICES(不足为奇)。我该如何实现呢？我被卡住了，请帮忙。

Answer 1

这是我的方法:

我使用 lazy 来延迟加载:

from django.utils.functional import lazy

在这里，选择选项的助手:

def help_SHOP_CHOICES():
    SHOP1_CHOICES = [
        ('Food Court', 'Food Court'),
        ('KFC', 'KFC'),
      ]
    SHOP3_CHOICES = [
        ('Bowling Arena', 'Bowling Arena'),
        ('Cinemax', 'Cinemax'),
      ]
    return random.choice( SHOP1_CHOICES + SHOP3_CHOICES )   # choose one

最后是动态选择的模型:

class Feed(models.Model):
  ...
  location=models.CharField(max_length=25, choices=SHOP1_CHOICES)

  def __init__(self, *args, **kwargs):
     super(Feed, self).__init__(*args, **kwargs)
     self._meta.get_field('location').choices = \
                        lazy(help_SHOP_CHOICES,list)()