python - 装饰器中的 Django Model._meta.get_fields()

Question

我需要访问装饰器中的模型类字段:

from django.db import models


class Register:
    REGISTRY = {}

    def __init__(self, name):
        self.name = name

    def __call__(self, cls):
        self.register(cls)
        return cls

    def register(self, cls):
        print(cls.__name__, '-', self.name)  # prints: Item - Item registered
        print(cls._meta.get_fields())  # raises: django.core.exceptions.AppRegistryNotReady: Models aren't loaded yet.

@Register('Item registered')
class Item(models.Model):
    title = models.CharField(max_length=200, verbose_name='Title')

cls._meta.get_fields() 引发: django.core.exceptions.AppRegistryNotReady:模型尚未加载。

如何访问字段？

Answer 1

所以，我尝试在我自己的机器上使用 django 1.8 复制它，我发现模型字段也可以通过 ._meta.fields 访问。

class Register:
    REGISTRY = {}

    def __init__(self, name):
        self.name = name

    def __call__(self, cls):
        self.register(cls)
        return cls

    def register(self, cls):
        print(cls.__name__, '-', self.name)  # prints: Item - Item registered
        print(cls._meta.fields) # prints all fields