Question

在电子学习平台https://github.com/PacktPublishing/Django-2-by-Example/tree/master/Chapter13/educa的代码中，我试图添加一个带有RelatedFieldWidgetWrapper和inlineformset的新记录（主题）。使用添加的代码，我得到错误“无属性_meta_get_field”。如何进行这项工作？

我更改了课程的admin.py，forms.py和views.py。这是我的代码和错误。

#admin.py
@admin.site.register(Subject, SubjectAdmin)
class SubjectAdmin(admin.ModelAdmin):
   model = Subject
   formset_factory = SubjectFormset

   def __init__(self, model, admin_site):
       super(SubjectAdmin, self).__init__(model, admin_site)
       self.form.admin_site = admin_site

admin.site.register(Subject, SubjectAdmin)

#models.py
class Subject(models.Model):
   title = models.CharField(max_length=200)
   slug = models.SlugField(max_length=200, unique=True)

   class Meta:
       ordering = ['title']

   def __str__(self):
       return self.title

class Course(models.Model):
   owner = models.ForeignKey(User, related_name='courses_created', on_delete=models.CASCADE)
   subject = models.ForeignKey(Subject, related_name='courses', on_delete=models.CASCADE)
   title = models.CharField(max_length=200)
   slug = models.SlugField(max_length=200, unique=True)
   overview = models.TextField()
   created = models.DateTimeField(auto_now_add=True)
   students = models.ManyToManyField(User, related_name='courses_joined', blank=True)

   class Meta:
       ordering = ['-created']

   def __str__(self):
       return self.title

#forms.py
SubjectFormset = inlineformset_factory(
               Subject, 
               Course, 
               fields = ['title', 'overview'],
               list_display = ['title', 'slug'],
               prepopulated_fields = {'slug': ('title',)},
               title = ModelMultipleChoiceField(queryset=Subject.objects.none()),
               widgets = RelatedFieldWidgetWrapper(
               FilteredSelectMultiple(('title'),False,),
               Subject._meta_get_field('title').field.remote_field.model, admin_site))


class Media:

   ## media for the FilteredSelectMultiple widget
   css = {
       'all':('/media/css/widgets.css/',),
   }
   # jsi18n is required by the widget
   js = ('/admin/jsi18n/',)

class Meta:
   model = Subject

#views.py
class OwnerCourseMixin(OwnerMixin, LoginRequiredMixin):
   model = Course
   formset_factory  = SubjectFormset
   #fields = ['subject', 'title', 'slug', 'overview']
   success_url = reverse_lazy('manage_course_list')


#error
Unhandled exception in thread started by <function check_errors.<locals>.wrapper at 0x75a90468>
Traceback (most recent call last):
 File "/usr/local/lib/python3.5/dist-packages/django/utils/autoreload.py", line 225, in wrapper
   fn(*args, **kwargs)
 File "/usr/local/lib/python3.5/dist-packages/django/core/management/commands/runserver.py", line 109, in inner_run
   autoreload.raise_last_exception()
 File "/usr/local/lib/python3.5/dist-packages/django/utils/autoreload.py", line 248, in raise_last_exception
   raise _exception[1]
 File "/usr/local/lib/python3.5/dist-packages/django/core/management/__init__.py", line 337, in execute
   autoreload.check_errors(django.setup)()
 File "/usr/local/lib/python3.5/dist-packages/django/utils/autoreload.py", line 225, in wrapper
   fn(*args, **kwargs)
 File "/usr/local/lib/python3.5/dist-packages/django/__init__.py", line 24, in setup
   apps.populate(settings.INSTALLED_APPS)
 File "/usr/local/lib/python3.5/dist-packages/django/apps/registry.py", line 120, in populate
   app_config.ready()
 File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/apps.py", line 24, in ready
   self.module.autodiscover()
 File "/usr/local/lib/python3.5/dist-packages/django/contrib/admin/__init__.py", line 26, in autodiscover
   autodiscover_modules('admin', register_to=site)
 File "/usr/local/lib/python3.5/dist-packages/django/utils/module_loading.py", line 47, in autodiscover_modules
   import_module('%s.%s' % (app_config.name, module_to_search))
 File "/usr/lib/python3.5/importlib/__init__.py", line 126, in import_module
   return _bootstrap._gcd_import(name[level:], package, level)
 File "<frozen importlib._bootstrap>", line 986, in _gcd_import
 File "<frozen importlib._bootstrap>", line 969, in _find_and_load
 File "<frozen importlib._bootstrap>", line 958, in _find_and_load_unlocked
 File "<frozen importlib._bootstrap>", line 673, in _load_unlocked
 File "<frozen importlib._bootstrap_external>", line 673, in exec_module
 File "<frozen importlib._bootstrap>", line 222, in _call_with_frames_removed
 File "/home/action/educa/courses/admin.py", line 4, in <module>
   from .forms import SubjectFormset
 File "/home/action/educa/courses/forms.py", line 24, in <module>
   Subject._meta_get_field('title').field.remote_field.model, admin_site))
AttributeError: type object 'Subject' has no attribute '_meta_get_field'

如何使用RelatedFieldWidgetWrapper修复inlineformset上的属性错误？

0 个答案: