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python - 如何在 django 中按父类别订购模型？

问题描述

我有一个模型“类别”，其外键为“parent_category”。如何在 Django 管理列表视图中订购此模型，例如：

- category 1
-- subcategory 1 of category 1
--- subsubcategory 1 of subcategory 1 of category 1
-- subcategory 2 of category 1
-- subcategory 3 of category 1
- category 2
-- subcategory 1 of category 2
-- subcategory 2 of category 2

我尝试了以下方法，但这不起作用。所以我需要一些帮助来订购函数'get_relative_name'。

class PrivateContentCategory(models.Model):
    name = models.CharField(
        max_length=250,
        verbose_name=_('Naam'),
    )
    slug = models.SlugField(
        verbose_name=_('Url'),
        blank=True,
    )
    parent_category = models.ForeignKey(
        'self',
        on_delete=models.SET_NULL,
        related_name='child_category_list',
        verbose_name=_('Hoofdcategorie'),
        blank=True,
        null=True,
    )

    def __str__(self):
        str = self.name
        parent_category_obj = self.parent_category
        while parent_category_obj is not None:
            str = parent_category_obj.name + ' --> ' + str
            parent_category_obj = parent_category_obj.parent_category
        return str

    def get_relative_name(self):
        str = self.name
        parent_category_obj = self.parent_category
        while parent_category_obj is not None:
            str = '--' + str
            parent_category_obj = parent_category_obj.parent_category
    get_relative_name.short_description = _('Naam')
    get_relative_name.admin_order_field = [
        'parent_category__parent_category',
        'name',
    ]

编辑！！！父类别的名称不应与类别一起显示。我这样写是为了显示应该如何订购模型。列表的显示将是：

- OS
-- Windows
--- Windows 7
--- Windows 8
--- Windows 10
-- Mac
-- Linux
--- Debian
---- Ubuntu
--- Fedora
---- CentOS
---- Oracle Linux

标签： pythondjangodjango-modelsblogs

解决方案

对我有用的是向模型添加一个新字段“absolute_name”，该字段将自动填充 pre_save 信号。保存实例后，此字段将包含实例的所有 parent_categories 的名称，然后再包含它自己的名称。最后，我只需要在这个字段上订购实例：

class PrivateContentCategory(models.Model):
    name = models.CharField(
        max_length=250,
        verbose_name=_('Naam'),
    )
    slug = models.SlugField(
        verbose_name=_('Url'),
        blank=True,
    )
    parent_category = models.ForeignKey(
        'self',
        on_delete=models.SET_NULL,
        related_name='child_category_list',
        verbose_name=_('Hoofdcategorie'),
        blank=True,
        null=True,
    )
    absolute_name = models.TextField(
        verbose_name=_('Absolute naam'),
        blank=True,
    )

    def __str__(self):
        return self.absolute_name

    def get_relative_name(self):
        str = self.name
        parent_category_obj = self.parent_category
        while parent_category_obj is not None:
            str = '--' + str
            parent_category_obj = parent_category_obj.parent_category
        return str
    get_relative_name.short_description = _('Naam')
    get_relative_name.admin_order_field = [
        'absolute_name',
    ]

    class Meta:
        verbose_name = _('Privé inhoud categorie')
        verbose_name_plural = _('Privé inhoud categorieën')
        ordering = [
            'absolute_name',
        ]


@receiver(models.signals.pre_save, sender=PrivateContentCategory)
def pre_save_private_content_category_obj(sender, instance, **kwargs):
    # START Generate instance.absolute_name
    instance.absolute_name = instance.name
    parent_category_obj = instance.parent_category
    while parent_category_obj is not None:
        instance.absolute_name = parent_category_obj.name + ' --> ' + instance.absolute_name
        parent_category_obj = parent_category_obj.parent_category
    # END Generate instance.absolute_name

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