model inheritance

[Roberto López López]

Hi,

I am extending a 3rd party model in my application, using multi-table inheritance. I can create an instance and modify it, but when I try to list the created objects at http://localhost:8000/en/admin/news/news/ , I am getting a nice exception:

Traceback:
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  140.                     response = response.render()
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/response.py" in render
  105.             self.content = self.rendered_content
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/response.py" in rendered_content
  82.         content = template.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in render
  140.             return self._render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in _render
  134.         return self.nodelist.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in render
  830.                 bit = self.render_node(node, context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/debug.py" in render_node
  74.             return node.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/loader_tags.py" in render
  124.         return compiled_parent._render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in _render
  134.         return self.nodelist.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in render
  830.                 bit = self.render_node(node, context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/debug.py" in render_node
  74.             return node.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/loader_tags.py" in render
  124.         return compiled_parent._render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in _render
  134.         return self.nodelist.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in render
  830.                 bit = self.render_node(node, context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/debug.py" in render_node
  74.             return node.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/loader_tags.py" in render
  63.             result = block.nodelist.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in render
  830.                 bit = self.render_node(node, context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/debug.py" in render_node
  74.             return node.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/loader_tags.py" in render
  63.             result = block.nodelist.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in render
  830.                 bit = self.render_node(node, context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/debug.py" in render_node
  74.             return node.render(context)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/template/base.py" in render
  1185.                     _dict = func(*resolved_args, **resolved_kwargs)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/contrib/admin/templatetags/admin_list.py" in result_list
  286.             'results': list(results(cl))}
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/contrib/admin/templatetags/admin_list.py" in results
  264.             yield ResultList(None, items_for_result(cl, res, None))
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/contrib/admin/templatetags/admin_list.py" in __init__
  256.         super(ResultList, self).__init__(*items)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/contrib/admin/templatetags/admin_list.py" in items_for_result
  219.             url = cl.url_for_result(result)
File "/home/roberto/.virtualenvs/ve_news/local/lib/python2.7/site-packages/django/contrib/admin/views/main.py" in url_for_result
  380.         pk = getattr(result, self.pk_attname)

Exception Type: AttributeError at /en/admin/news/news/
Exception Value: 'News' object has no attribute 'news_ptr_id'

My News model is extending another model using multiple table inheritance.

class News(OldNews):
    departments = models.ManyToManyField(Department, blank=True, related_name='news')
    objects = models.Manager()
    class Meta:
        verbose_name_plural = _('news')
        ordering = ('-pub_date', )

I can't understand the reason for this error. Can anyone enlighten me please?

Roberto

[Leonardo Giordani]

Are you sure your DB has been synced after putting the ForeignKey(News) in your Department model?

Can you post somewhere the following models: News, OldNews, Department?

Regards,

Leo

Leonardo Giordani

Author of The Digital Cat
My profile on About.me - My GitHub page - My Coderwall profile

2013/10/2 Roberto López López <robert...@uni.no>

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[Roberto López López]

Hi Leonardo, thanks for your answer.

Yes, it has been synced.

The model itself is a little bit bigger, as you can notice from the code https://dpaste.de/c3Rg I am using as well the News model from https://github.com/wildfish/cmsplugin_news/blob/master/cmsplugin_news/models.py

Regards,

Roberto

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Roberto López López
System Developer
Parallab, Uni Computing
+47 55584091

[Roberto López López]

Is there maybe a way to set the cmsplugin_news.News.Meta.abstract option to True? In order to prevent accessing the parent model to fetch the inherited data.

On 10/02/2013 03:45 PM, Leonardo Giordani wrote:

To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAEhE%2BOkqZkwyR92m3DZATfoCA9bMVm8mT387oqw%3DM66F6-8EQw%40mail.gmail.com.

For more options, visit https://groups.google.com/groups/opt_out.