Вызов get_absolute_url от экземпляра связанной модели

Question

Объекты классов Task и Solution отображаются по одному URL. Соответсвенно я хочу получать адрес ссылки для объекта Solution через вызов фун get_absolute_url у связанного с ним таском (при изменении ссылки на Task не нужно настраивать ссылку для Solution).

in models.py

class Task(models.Model):
    ...
    @property
    def get_absolute_url(self):
        return reverse('task_detail', kwargs={'category_slug': self.category.slug, 'task_id': self.id})


class Solution(models.Model):
    ...
    task = models.ForeignKey(Task, related_name='solutions', on_delete=models.CASCADE, blank=True, null=True)

    @property
    def get_absolute_url(self):
        return self.task.get_absolute_url()

У меня возникает такая ошибка:

Environment:


Request Method: POST
Request URL: http://127.0.0.1:8000/impuls/task7/solution24/add-comment

Django Version: 3.2.5
Python Version: 3.8.10

Traceback (most recent call last):
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\core\handlers\base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\views\generic\base.py", line 70, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\views\generic\base.py", line 98, in dispatch
    return handler(request, *args, **kwargs)
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\views\generic\edit.py", line 172, in post
    return super().post(request, *args, **kwargs)
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\views\generic\edit.py", line 142, in post
    return self.form_valid(form)
  File "C:\Users\grigo\PycharmProjects\PhoForum\forum\views.py", line 117, in form_valid
    return super().form_valid(form)
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\contrib\messages\views.py", line 11, in form_valid
    response = super().form_valid(form)
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\views\generic\edit.py", line 126, in form_valid
    return super().form_valid(form)
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\views\generic\edit.py", line 57, in form_valid
    return HttpResponseRedirect(self.get_success_url())
  File "C:\Users\grigo\anaconda3\envs\PhoForum\lib\site-packages\django\views\generic\edit.py", line 116, in get_success_url
    url = self.object.get_absolute_url()

Exception Type: TypeError at /impuls/task7/solution24/add-comment
Exception Value: 'str' object is not callable

(если опустить скобки self.task.get_absolute_url такая же ошибка )

in views.py

class RequestCreateView(SuccessMessageMixin, CreateView):
    """ 
    Sub-class of the CreateView to automatically pass the Request to the Form. 
    """
    success_message = "Created Successfully"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context['form_value'] = "Save"


class SolutionCreateView(RequestCreateView):
    model = Solution
    form_class = SolutionForm
    template_name = 'forum/category/forms/comment_form.html'

    def form_valid(self, form):
        form.instance.author = self.request.user
        form.instance.task = get_object_or_404(Task, id=self.kwargs["task_id"])
        return super().form_valid(form)

in urls.py

urlpatterns = [
    ...
    path('<slug:category_slug>/task<int:task_id>', TaskDetail.as_view(), name='task_detail'),
    path('<slug:category_slug>/task<int:task_id>/add-solution', SolutionCreateView.as_view(), name='add_solution'),
]

Answer 1

class Task(models.Model):
    ...
    def get_absolute_url(self):
        return reverse('task_detail', kwargs={'category_slug': self.category.slug, 'task_id': self.id})


class Solution(models.Model):
    ...
    task = models.ForeignKey(Task, related_name='solutions', on_delete=models.CASCADE, blank=True, null=True)

    def get_absolute_url(self):
        if self.task:
            return self.task.get_absolute_url()
        # raise Exception("Нет таска, я не знаю что возврщать")
        return '#none'

БЛОГ НА HUSL

Вызов get_absolute_url от экземпляра связанной модели

Ответы (1 шт):