如何在Forms.py中进行链式选择？

Question

class Library(forms.ModelForm):

    author = forms.ChoiceField(
        widget = forms.Select(),
        choices = ([
            ('Jk Rowling','Jk Rowling'), 
            ('agatha christie','agatha christie'),
            ('mark twain','mark twain'), 
        ]),
        initial = '1', 
        required = True,
    )
    books = forms.ChoiceField(
        widget = forms.Select(), 
        choices = ([
            ('Harry Potter 1','Harry Potter 1'),  # 1
            ('Harry Potter 2','Harry Potter 2'),  # 2
            ('Harry Potter 3','Harry Potter 3'),  # 3
            ('Harry Potter 4','Harry Potter 4'),  # 4
            ('The A.B.C. Murders','The A.B.C. Murders'),  # 5
            ('Dumb Witness','Dumb Witness'),  # 6
            ('Death on the Nile','Death on the Nile'),  # 7
            ('Murder Is Easy','Murder Is Easy'),  # 8
            ('Roughing It','Roughing It'),  # 9
            (' The Gilded Age ',' The Gilded Age '),  # 10
            ('Adventures of Tom Sawyer','Adventures of Tom Sawyer'),  # 11
        ]),
        initial = '1',
        required = True,
    )

如果用户选择作者为Jk，则必须在“图书选择”字段中填充“哈利·波特”系列(1至4项选择)。

如果用户选择作者为Agatha Christie，则必须在“图书选择”字段中填充(5至8)

如果用户选择作者为Mark，则必须在图书选择字段的select小部件中填充(8至11 )选项

我想过滤那些选择谁能帮上忙吗？

Answer 1

将author和books保存在DB中。

models.py

Class Author(models.Model):
    name = models.CharField(max_length=50)
    ......

class Books(models.Model):
    ....
    author = models.ForeignField(Author)
    ....

Class Library(models.Model):
    .....
    author = models.ForeignKey(Author)
    books = models.ForeignKey(Books)
    .....

forms.py

class Library(forms.ModelForm):

    def __init__(self, *args, **kwargs):
        super(Library, self).__init__(*args, **kwargs)
        self.fields['author'].choices = list(Author.objects.values_list('id', 'name'))

        self.fields['books'].choices = list(Books.objects.values_list('id', 'name'))


    class Meta:
        Model: Library

在Author选择的基础上，从ajax调用触发器得到所有对应的books。