在 Django Admin 中将 ManyToManyWidget 添加到 ManyToManyField 的反面

Question

假设我在 Django 1.4 中有一个简单的博客应用程序：

class Post(models.Model):
    title = …
    published_on = …
    tags = models.ManyToManyField('Tag')

class Tag(models.Model):
    name = …

即一个帖子有很多标签。在 Django 管理员中，如果我在 fields 中包含 tags 来表示 PostAdmin，我会得到一个不错的小 <select multi>。有没有一种简单的方法可以在TagAdmin 中包含帖子列表（作为简单的<select multi>）？我尝试将fields = ['name', 'posts'] 放入TagAdmin 并得到ImproperlyConfigured 错误。 （post_set 的结果相同）。

我对 Django 没问题，所以可以创建一个适当的 AdminForm 和 Admin 对象，但我希望有一个 Right Way™ 来做。

Answer 1

这可以通过自定义表单来实现。

from django.contrib import admin
from django import forms

from models import Post, Tag

class PostAdminForm(forms.ModelForm):
    tags = forms.ModelMultipleChoiceField(
        Tag.objects.all(),
        widget=admin.widgets.FilteredSelectMultiple('Tags', False),
        required=False,
    )

    def __init__(self, *args, **kwargs):
        super(PostAdminForm, self).__init__(*args, **kwargs)
        if self.instance.pk:
            self.initial['tags'] = self.instance.tags.values_list('pk', flat=True)

    def save(self, *args, **kwargs):
        instance = super(PostAdminForm, self).save(*args, **kwargs)
        if instance.pk:
            instance.tags.clear()
            instance.tags.add(*self.cleaned_data['tags'])
        return instance

class PostAdmin(admin.ModelAdmin):
    form = PostAdminForm

admin.site.register(Post, PostAdmin)

如果您想要垂直堆叠的小部件，可以将其中的 False 替换为 True。

Answer 2

聚会有点晚了，但这是对我有用的解决方案（没有魔法）：

# admin.py

from django.contrib import admin
from models import Post

class TagPostInline(admin.TabularInline):
    model = Post.tags.through
    extra = 1

class PostAdmin(admin.ModelAdmin):
    inlines = [TagPostInline]

admin.site.register(Post, PostAdmin)

参考：https://docs.djangoproject.com/en/dev/ref/contrib/admin/#working-with-many-to-many-models

Answer 3

修改模型以添加反向字段：

# models.py
from django.db import models

class Post(models.Model):
    title = models.CharField(max_length=100)
    published_on = models.DateTimeField()
    tags = models.ManyToManyField('Tag')

class Tag(models.Model):
    name = models.CharField(max_length=10)
    posts = models.ManyToManyField('blog.Post', through='blog.post_tags')

然后以标准方式将字段添加到 ModelAdmin：

#admin.py
from django.contrib import admin

class TagAdmin(admin.ModelAdmin):
    list_filter = ('posts', )

admin.site.register(Tag, TagAdmin)

Answer 4

创建新条目时，Matthew 的解决方案对我 (Django 1.7) 不起作用，因此我不得不对其进行一些更改。我希望它对某人有用:)

class PortfolioCategoriesForm(forms.ModelForm):
    items = forms.ModelMultipleChoiceField(
        PortfolioItem.objects.all(),
        widget=admin.widgets.FilteredSelectMultiple('Portfolio items', False),
        required=False
    )

    def __init__(self, *args, **kwargs):
        super(PortfolioCategoriesForm, self).__init__(*args, **kwargs)
        if self.instance.pk:
            initial_items = self.instance.items.values_list('pk', flat=True)
            self.initial['items'] = initial_items

    def save(self, *args, **kwargs):
        kwargs['commit'] = True
        return super(PortfolioCategoriesForm, self).save(*args, **kwargs)

    def save_m2m(self):
        self.instance.items.clear()
        self.instance.items.add(*self.cleaned_data['items'])

Answer 5

您可以通过这种方式添加对称的多对多过滤器。

功劳归于 https://gist.github.com/Grokzen/a64321dd69339c42a184

from django.db import models

class Pizza(models.Model):
  name = models.CharField(max_length=50)
  toppings = models.ManyToManyField(Topping, related_name='pizzas')

class Topping(models.Model):
  name = models.CharField(max_length=50)

### pizza/admin.py ###

from django import forms
from django.contrib import admin
from django.utils.translation import ugettext_lazy as _
from django.contrib.admin.widgets import FilteredSelectMultiple

from .models import Pizza, Topping

class PizzaAdmin(admin.ModelAdmin):
  filter_horizonal = ('toppings',)

class ToppingAdminForm(forms.ModelForm):
  pizzas = forms.ModelMultipleChoiceField(
    queryset=Pizza.objects.all(), 
    required=False,
    widget=FilteredSelectMultiple(
      verbose_name=_('Pizzas'),
      is_stacked=False
    )
  )

  class Meta:
    model = Topping

  def __init__(self, *args, **kwargs):
    super(ToppingAdminForm, self).__init__(*args, **kwargs)

    if self.instance and self.instance.pk:
      self.fields['pizzas'].initial = self.instance.pizzas.all()

  def save(self, commit=True):
    topping = super(ToppingAdminForm, self).save(commit=False)

    if commit:
      topping.save()

    if topping.pk:
      topping.pizzas = self.cleaned_data['pizzas']
      self.save_m2m()

    return topping

class ToppingAdmin(admin.ModelAdmin):
  form = ToppingAdminForm

admin.site.register(Pizza, PizzaAdmin)
admin.site.register(Topping, ToppingAdmin)