ManyToManyField widget in a django admin change list?

Question

In the change list of the django admin, I want to use list_editable to display a django-autocomplete widget for a ManyToManyField.

I found something similar here: list_editable and widgets

Normally including a ManyToManyField in list_display raises an ImproperlyConfigured exception, eg:

""'BookAdmin.list_display[2]', 'author' is a ManyToManyField which is not supported."

I (perhaps unwisely) removed 3 lines from contrib/admin/validate.py to bypass the exception. :)

I now have it spitting out the following, which is close(?) but no cigar.

<django.db.models.fields.related.ManyRelatedManager object at 0x1032a85d0>

Any thoughts on how to proceed? Is there a better way of doing this?

Here's what I have at the moment: (AuthorAutocomplete is working fine in the regular admin form)

class AuthorAutocomplete(AutocompleteSettings):
    search_fields = ('first_name', 'last_name')

class BookAdmin(AutocompleteAdmin, admin.ModelAdmin):
    def get_changelist_form(self, request, **kwargs):
      kwargs.setdefault('form', AuthorAutocompleteForm)
      return super(BookAdmin, self).get_changelist_form(request, **kwargs)    
      list_display = ['isbn', 'title', 'author', 'publisher']
      #...

class AuthorAutocompleteForm(forms.ModelForm):
    class Meta:
        model  = Book
    author = AuthorAutocomplete

Thanks!

Answer 1

This is an old topic, but I'm hoping this might help someone else.

To get the values for a ManyToMany field so you can display their values you can do the follow. I'm using list_display as an example.

class TestAdmin(admin.ModelAdmin):
    def get_some_value(self):
        return ", " . join([x.__str__() for x in self.manytomany_field.all()])

    list_display(get_some_value)
    get_some_value.short_description = 'Title' #sets column header to Title

Answer 2

Silly me. I thought that William's manytomany_field was a built-in ModelAdmin object. So I ran his code as is (after putting in the missing parenthesis after join).

Strange to say, it ran without producing an error message. But (None) appeared when I was supposed to get values. And I thought it was strange that I couldn't find anything when I Googled "django model.Admin.manytomany_field". Hah!

So eventually I realized that I was to put the NAME of the many-to-many field in place of manytomany_field. It works!