python – Django Admin – 显示M2M模型的中介字段

2023年10月23日 249次阅读

我们有一个Django应用程序,其中包含一份报纸文章列表.每篇文章都与“发言人”以及“公司”(文章中提到的公司)有m2m关系.

目前,用于创建新文章的添加文章页面非常接近我们想要的 – 它只是股票Django Admin,我们使用filter_horizo​​ntal来设置两个m2m关系.

下一步是在每个m2m关系上添加“评级”字段作为中间字段.

所以,我们的models.py的一个例子

class Article(models.Model):
    title = models.CharField(max_length=100)
    publication_date = models.DateField()
    entry_date = models.DateField(auto_now_add=True)
    abstract = models.TextField() # Can we restrict this to 450 characters?
    category = models.ForeignKey(Category)
    subject = models.ForeignKey(Subject)
    weekly_summary = models.BooleanField(help_text = 'Should this article be included in the weekly summary?')
    source_publication = models.ForeignKey(Publication)
    page_number = models.CharField(max_length=30)
    article_softcopy = models.FileField(upload_to='article_scans', null=True, blank=True, help_text='Optionally upload a soft-copy (scan) of the article.')
    url = models.URLField(null=True, blank=True, help_text = 'Enter a URL for the article. Include the protocl (e.g. http)')
    firm = models.ManyToManyField(Firm, null=True, blank=True, through='FirmRating')
    spokesperson = models.ManyToManyField(Spokeperson, null=True, blank=True, through='SpokespersonRating')

    def __unicode__(self):
        return self.title

class Firm(models.Model):
    name = models.CharField(max_length=50, unique=True)
    homepage = models.URLField(verify_exists=False, help_text='Enter the homepage of the firm. Include the protocol (e.g. http)')

    def __unicode__(self):
        return self.name

    class Meta:
        ordering = ['name']

class Spokeperson(models.Model):
    title = models.CharField(max_length=100)
    first_name = models.CharField(max_length=50)
    last_name = models.CharField(max_length=50)

    def __unicode__(self):
        return self.first_name + ' ' + self.last_name

    class Meta:
        ordering = ['last_name', 'first_name']

class FirmRating(models.Model):
    firm = models.ForeignKey(Firm)
    article = models.ForeignKey(Article)
    rating = models.IntegerField()

class SpokespersonRating(models.Model):
    firm = models.ForeignKey(Spokesperson)
    article = models.ForeignKey(Article)
    rating = models.IntegerField()

这里的问题是,一旦我们将我们的公司和发言人字段更改为“通过”并使用中介,我们的添加文章页面就不再具有filter_horizo​​ntal控件来向文章添加Firms / Spokeperson关系 – 它们完全消失.你根本看不到它们.我不知道为什么会这样.

我希望有一些方法继续使用酷filter_horizo​​ntal小部件来设置关系,并以某种方式只是嵌入下面的另一个字段来设置评级.但是,我不知道如何做到这一点,同时仍然利用Django管理员.

我在这里看到一篇关于覆盖Django管理员中的单个小部件的文章：

http://www.fictitiousnonsense.com/archives/22

但是,我不确定该方法是否仍然有效,而且我不确定是否将它应用于此处,将FK应用于中间模型(它基本上是内联的？).

当然有一种简单的方法可以做到这一切吗？

干杯,
胜利者

最佳答案 问题是django.contrib.admin.options中的admin方法formfield_for_manytomany没有返回带有中间模型的多个字段的表单字段！
http://code.djangoproject.com/browser/django/trunk/django/contrib/admin/options.py#L157

您必须在ModelAdmin中覆盖此方法：

def formfield_for_manytomany(self, db_field, request=None, **kwargs):
    """
    Get a form Field for a ManyToManyField.
    """
    # If it uses an intermediary model that isn't auto created, don't show
    # a field in admin.
    if not db_field.rel.through._meta.auto_created:
        return None    # return something suitable for your needs here!
    db = kwargs.get('using')

    if db_field.name in self.raw_id_fields:
        kwargs['widget'] = widgets.ManyToManyRawIdWidget(db_field.rel, using=db)
        kwargs['help_text'] = ''
    elif db_field.name in (list(self.filter_vertical) + list(self.filter_horizontal)):
        kwargs['widget'] = widgets.FilteredSelectMultiple(db_field.verbose_name, (db_field.name in self.filter_vertical))
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