Question

我有这些模特：

class Category(models.Model):
    name = models.CharField(max_length=10)
    uuid = models.CharField(max_length=36)

class Item(models.Model):
    name = models.CharField(max_length=255)
    uuid = models.CharField(max_length=36)
    categories = models.ManyToManyField(Category, null=True)
    brand = models.ForeignKey(Brand)

我试图用django-tables2在表格中显示Item模型，如下所示：

class ItemTable(tables.Table):
    class Meta:
        model = Item
        attrs = {"class": "paleblue"}
        fields = ("uuid", "name", "brand", "categories")

    categories = tables.Column(empty_values=())

    def render_categories(self, value):
        return ', '.join([category.name for category in value.all()])

它工作正常，但Table忽略categories字段和。{ value参数等于None，我收到错误'NoneType' object has no attribute 'all'

我做错了什么？感谢。

Answer 1

这样做：

class ItemTable(tables.Table):
    class Meta:
        model = Item
        attrs = {"class": "paleblue"}
        fields = ("uuid", "name", "brand", "categories")

    categories = tables.Column()

    def render_categories(self, value):
        if value is not None:
            return ', '.join([category.name for category in value.all()])
        return '-'

Answer 2

当使用django 1.7时，看起来这是django-tables2中的错误： https://github.com/bradleyayers/django-tables2/issues/211

Answer 3

看起来它还没有被合并。作为一种解决方法，你可以使用记录进行渲染并以相同的方式迭代。

即

 def render_categories(self, record):
        if record.category is not None:
            return ', '.join([category.name for category in record.category.all()])
        return '-'

Answer 4

也许不是更清洁的选择，但这对我有用：

class Item(models.Model):
    name = models.CharField(max_length=255)
    uuid = models.CharField(max_length=36)
    categories = models.ManyToManyField(Category, null=True)
    brand = models.ForeignKey(Brand)

   @property
   def categories_str(self):
       return ', '.join([category.name for category in value.all()])


class ItemTable(tables.Table):
    categories = tables.Column(accessor='categories_str')

    class Meta:
        model = Item
        attrs = {"class": "paleblue"}
        fields = ("uuid", "name", "brand", "categories")

Answer 5

执行此操作：

class ItemTable(tables.Table):
    class Meta:
        model = Item
        attrs = {"class": "paleblue"}
        fields = ("uuid", "name", "brand", "categories")

    categories = tables.Column(empty_values=())

    def render_categories(self, record):
        if record.categories.all():
            return ', '.join([category.name for category in record.categories.all()])
        return '-'

请注意，empty_values =（）对于写入tables.Column（）

非常重要

django-tables2忽略ManyToManyField

5 个答案: