AttributeError: 'str' object has no attribute '_meta'

问题:

I just begin to study Django, and today come to the comment part, I just practice from the Django Document.https://docs.djangoproject.com/en/1.4/ref/contrib/comments/example/. The command to add comment form works well when i do my practice on DetailView page but now I also want to add a comment form to ListView page then it got this error.

below is the traceback: Environment: Request Method: GET

Django Version: 1.4.3 Python Version: 2.7.3 Installed Applications: ('django.contrib.auth', 'django.contrib.contenttypes', 'django.contrib.sessions', 'django.contrib.sites', 'django.contrib.messages', 'django.contrib.staticfiles', 'django.contrib.admin', 'books', 'django.contrib.comments') Installed Middleware: ('django.middleware.common.CommonMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware', 'django.contrib.messages.middleware.MessageMiddleware')   Template error: In template /home/ryu/emacs/emacs-code/djcode/mysite2/templates/books/publisher_list.html, error at line 19 'str' object has no attribute '_meta'   9 :   <th> website</th>   10 : </tr>   11 : {% for publisher in object_list %}   12 : <tr>   13 :   <th><a href="/mysite2/publishers/{{publisher.id}}">{{ publisher.name }}</a></th>     14 :   <th>{{publisher.country}}</th>   15 :   <th>{{publisher.website}}</th>   16 : </tr>    17 : {% endfor %}   18 : </table>   19 :  {% render_comment_list for books.publisher %}    20 : {% endblock %}   21 :  Traceback: File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response 136.                     response = response.render() File "/usr/local/lib/python2.7/dist-packages/django/template/response.py" in render 104.             self._set_content(self.rendered_content) File "/usr/local/lib/python2.7/dist-packages/django/template/response.py" in       rendered_content 81.         content = template.render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in render 140.             return self._render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in _render 134.         return self.nodelist.render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in render 823.                 bit = self.render_node(node, context) File "/usr/local/lib/python2.7/dist-packages/django/template/debug.py" in render_node 74.             return node.render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/loader_tags.py" in render 123.         return compiled_parent._render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in _render 134.         return self.nodelist.render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in render 823.                 bit = self.render_node(node, context) File "/usr/local/lib/python2.7/dist-packages/django/template/debug.py" in render_node 74.             return node.render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/loader_tags.py" in render 123.         return compiled_parent._render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in _render 134.         return self.nodelist.render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in render 823.                 bit = self.render_node(node, context) File "/usr/local/lib/python2.7/dist-packages/django/template/debug.py" in render_node 74.             return node.render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/loader_tags.py" in render 62.             result = block.nodelist.render(context) File "/usr/local/lib/python2.7/dist-packages/django/template/base.py" in render 823.                 bit = self.render_node(node, context) File "/usr/local/lib/python2.7/dist-packages/django/template/debug.py" in render_node 74.             return node.render(context) File "/usr/local/lib/python2.7/dist-          packages/django/contrib/comments/templatetags/comments.py" in render 201.         ctype, object_pk = self.get_target_ctype_pk(context) File "/usr/local/lib/python2.7/dist- packages/django/contrib/comments/templatetags/comments.py" in get_target_ctype_pk 100.             return ContentType.objects.get_for_model(obj), obj.pk File "/usr/local/lib/python2.7/dist-packages/django/contrib/contenttypes/models.py" in get_for_model 32.         opts = self._get_opts(model) File "/usr/local/lib/python2.7/dist-packages/django/contrib/contenttypes/models.py" in   _get_opts 20.         return model._meta.concrete_model._meta  Exception Type: AttributeError at /mysite2/publishers/ Exception Value: 'str' object has no attribute '_meta' 

now I want to know how could i add every page a comment using the build-in comments??

回答1:

What you are saying then is that you pass appname.modelname to the template tag, you should actually pass an instance of the model to the template tag something like:

{% render_comment_list for publisher %} 

if publisher is an instance of the Publisher model as it looks to be in your code. Or alternatively:

{% render_comment_list for books.publisher publisher.id %} 

as psjinx mentioned above.

回答2:

render_comment_list tag expects an object but you are passing unicode string. book.publisher in Line 19, where exception is being raised` appears to be a string.

You can see valid arguments here. Here is the source code for this tag:

@register.tag def render_comment_list(parser, token):     """     Render the comment list (as returned by ``{% get_comment_list %}``)     through the ``comments/list.html`` template      Syntax::          {% render_comment_list for [object] %}         {% render_comment_list for [app].[model] [object_id] %}      Example usage::          {% render_comment_list for event %}      """     return RenderCommentListNode.handle_token(parser, token) 

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