如何添加optgroups到django ModelMultipleChoiceField？

Question

我有一個表格，ModelMultipleChoiceField到類別列表。 我想使用Category.group字段對類別進行分組。

我以爲通過改變字段。 choices在init函數就會使的伎倆

class CategoriesField(forms.ModelMultipleChoiceField): 
    def __init__(self, queryset, **kwargs): 
     super(forms.ModelMultipleChoiceField, self).__init__(queryset, **kwargs) 
     self.queryset = queryset.select_related() 
     self.to_field_name=None 

     group = None 
     list = [] 
     self.choices = [] 

     for category in queryset: 
      if not group: 
       group = category.group 

      if group != category.group: 
       self.choices.append((group.title, list)) 
       group = category.group 
       list = [(category.id, category.name)] 
      else: 
       list.append((category.id, category.name)) 
     try: 
      self.choices.append((group.title, list)) 
     except: 
      pass 

但ModelChoiceIterator還是抹去self.choices信息被在__init__功能設置。

我該如何做到這一點？

Answer 1

事實上，它正在像我剛纔解釋，但不要忘了，部分：

class ProfilForm(ModelForm): 
    categories = CategoriesField(queryset=Category.objects.all().order_by('group'), label=_(u'Catégories')) 

Answer 2

我發現這個問題/答案有幫助，但改變了代碼了很多。上述代碼的問題在於，它只生成一次列表，然後緩存（查詢集僅使用一次）。我的代碼是針對「配置文件」（又名作者）排序的「文章」對象，但任何人都應該能夠對其進行修改以供其使用。它每次都使用一個新的查詢集，因此它在沒有重新啓動的情況下進行更新（除非您將cache_choices=True傳遞給ArticleMultipleChoiceField然後將其緩存）。

class ArticleChoiceIterator(forms.models.ModelChoiceIterator): 
    def __iter__(self): 
     if self.field.empty_label is not None: 
      yield ("", self.field.empty_label) 
     if self.field.cache_choices: 
      if self.field.choice_cache is None: 
       last_profile = None 
       self.field.choice_cache = [] 
       for article in self.queryset.all(): 
        if last_profile != article.profile: 
         last_profile = article.profile 
         article_list = [] 
         self.field.choice_cache.append((article.profile.name, article_list)) 
        article_list.append(self.choice(article)) 
      for choice in self.field.choice_cache: 
       yield choice 
     else: 
      last_profile = None 
      article_choices = [] 
      for article in self.queryset.all(): 
       if last_profile != article.profile: 
        if article_choices: 
         yield (getattr(last_profile, 'name', ''), article_choices) 
        last_profile = article.profile 
        article_choices = [] 
       article_choices.append(self.choice(article)) 
      if article_choices: 
       yield (getattr(last_profile, 'name', ''), article_choices) 


class ArticleMultipleChoiceField(forms.ModelMultipleChoiceField): 
    # make sure queryset is ordered by profile first! 
    def __init__(self, queryset, **kwargs): 
     super(ArticleMultipleChoiceField, self).__init__(queryset, **kwargs) 
     self.queryset = queryset.select_related('profile') 
     self._choices = ArticleChoiceIterator(self) 


class PackageForm(forms.ModelForm): 
    articles = ArticleMultipleChoiceField(
     queryset=Article.objects.order_by('profile__name', 'title') 
    )