CODEWITHSUNDEEP
djangodjango-adminmulti-table-inheritance
sogeking
sogeking

Reputation: 1276

model inheritance + django admin

I am reusing the News model from cmsplugin_news, just adding some extra fields in my inheriting model. (Multi-table inheritance, just as explained here.

from cmsplugin_news.models import News

class News(News):
    departments = models.ManyToManyField('department.Department', blank=True, related_name="news")

On my admin.py I am extending NewsAdmin to set my own form:

class MyNewsAdmin(NewsAdmin):
    form = NewsModelForm

Which I have defined in forms.py:

from news.models import News

class NewsModelForm(NewsForm):
    class Meta:
        model = News
        widgets = {
            'excerpt': CKEditorWidget(config_name='basic'),
            'content': CKEditorWidget(config_name='default')
        }

    def _get_widget(self):
        from ckeditor.widgets import CKEditorWidget
        return CKEditorWidget()

The model inheritance seems to work well when I save objects from the shell console. But when I try to create a MyNews object from the django admin and link it to a department, this field is not saved. Or at least this change is not shown anywhere

unicms-testnews=> select * from cmsplugin_news_news;
 id | title | slug | excerpt | content | is_published |        pub_date        |            created            |            updated            | link 
----+-------+------+---------+---------+--------------+------------------------+-------------------------------+-------------------------------+------
  1 | dfad  | dfad |         |         | f            | 2013-09-10 13:44:46+02 | 2013-09-10 13:45:04.709556+02 | 2013-09-10 13:57:05.568696+02 | 
(1 row)
unicms-testnews=> select * from news_news;
 news_ptr_id 
-------------
           1
(1 row)

unicms-testnews=> select * from news_news_departments;
 id | news_id | department_id 
----+---------+---------------
  1 |       1 |             1
(1 row)

I can't understand anything, can anyone help me please? Thank you very much!

Upvotes: 0

Views: 1486

Answers (1)

Ricola3D
Ricola3D

Reputation: 2442

You created a form for News, that also exist in your DB since the model is not abstract, not for MyNews. Thus your current form has no field for the departments attribute, even if you add a widget with an input for it. Do the code bellow instead:

class MyNewsForm(NewsForm):
    class Meta:
        model = MyNews # instead of just News
        ...

What Django does in background is to create two relations: the cmsplugin_news_news stores all the News fields, and the news_news_departments stores your new field and is in one-to-one relation with the first relation.

Upvotes: 1

Related Questions