Displaying both sides of a ManyToMany relationship in Django admin

Question

Say I have the following models that have a many-to-many relationship:

models.py:

class Foo(models.Model):

    name = models.TextField()


class Bar(models.Model):

    name = models.TextField()
    foos = models.ManyToManyField(Foo, related_name='bars')

And then having defined them in admin in the following way:

admin.py

@admin.register(Foo)
class FooAdmin(admin.ModelAdmin):
    """Foo admin."""

    list_display = ('name',)
    search_fields = ('name',)


@admin.register(Bar)
class BarAdmin(admin.ModelAdmin):
    """Bar admin."""

    list_display = ('name',)
    search_fields = ('name',)

In Django admin, when browsing Bar instances, I can see the Foo instances Bar is associated with and can modify them from there.

However, no such luck with Foo, I can't see the Bar instances that every Foo object is associated with.

Can Django define automatic handling for this or would I need to roll my own methond?

I'm using Python 3.6.1 and Django 1.11.

Answer 1

You could define a custom InlineModelAdmin like so:

class BarInline(admin.TabularInline):
    model = Bar.foos.through

and use it in your FooAdmin:

class FooAdmin(admin.ModelAdmin):
"""Foo admin."""
    model = Foo
    inlines = [
        BarInline,
    ]

Have a look at this part of the django documentation.