ManyToManyField验证错误

Question

我使用的是选择的jquery。我已经在ManyToMany和ForeignKey上添加了null=True和blank=True。但是为什么我在模板中的ManyToManyField上得到验证错误呢？我尝试在没有填写ManyToManyField和ForeignKey的情况下提交表单，在管理中可以正常工作，但在模板中不能。你能帮帮忙吗？谢谢

ManyToManyError - Enter a list of values.

模型

class Movie(models.Model):
    title = models.CharField(max_length=100)
    slug = models.SlugField(unique=True, max_length=100)
    director = models.ManyToManyField(Director, null=True, blank=True)
    writer = models.ManyToManyField(Writer, null=True, blank=True)
    producer = models.ManyToManyField(Producer, null=True, blank=True)
    starring = models.ManyToManyField(Starring, null=True, blank=True)
    screenplay = models.ManyToManyField(Screenplay, null=True, blank=True)

    editing = models.ForeignKey(Editing, null=True, blank=True)
    music = models.ForeignKey(Music, null=True, blank=True)
    studio = models.ForeignKey(Studio, null=True, blank=True)
    image = models.CharField(max_length=200, null=True, blank=True)

MovieForm

class MovieForm(ModelForm):

  class Meta:
    model = Movie
    exclude = ('slug', 'image')
    widgets = {
        'director': Select(attrs={'multiple class': 'chzn-select'}),
        'starring': Select(attrs={'multiple class': 'chzn-select'}),
        'producer': Select(attrs={'class': 'chzn-select'}),
        'writer': Select(attrs={'class': 'chzn-select'}),
        'studio': Select(attrs={'class': 'chzn-select'}),
        'editing': Select(attrs={'class': 'chzn-select'}),
        'screenplay': Select(attrs={'class': 'chzn-select'}),
        'music': Select(attrs={'class': 'chzn-select'}),
    }

Answer 1

错误消息"Enter a list of value“暗示从表单返回的值不是列表或元组的实例，我认为问题是您使用的是Select小部件，它返回单个值(‘’如果为空)，也许您应该使用SelectMultiple

class MovieForm(ModelForm):
    class Meta:
        model = Movie
        exclude = ('slug', 'image')
        widgets = {
            'director': SelectMultiple(attrs={'class': 'chzn-select'}),
            ...
        } 

或者，您可以在清理表单之前手动将值转换为list/tuple。