django：如何使用動態0-n可能性的ModelForm？

Question

The Quetion

你好。我試圖找出使用一種形式創建一個父對象然後創建0-n個子對象的最佳方式。我假設ModelForms是我需要做的，但我很難理解如何構建模板和視圖。有人願意解釋如何創建n個子對象嗎？

研究

我讀過有關這幾個其他文章和帖子：

• django model/modelForm - How to get dynamic choices in choiceField?
• https://stackoverflow.com/questions/5575560/how-do-i-create-a-drop-down-menu-in-django-using-a-modelform-with-dynamic-values
• http://collingrady.wordpress.com/2008/02/18/editing-multiple-objects-in-django-with-newforms/
• Overriding the save method in Django ModelForm

僅舉幾例。

的詳細

我有這樣兩種模式，以便：

// models.py

class DataItem(models.Model): 
    name = models.CharField(max_length=255) 
    date_created = models.DateTimeField(auto_now_add=True) 
    date_last_updated = models.DateTimeField(auto_now_add=True) 
    owner = models.ForeignKey(User, blank=False) 

    def __unicode__(self): 
     return self.name 

class DataItemSet(models.Model): 
    item = models.ForeignKey(DataItem, blank=False) 
    type_ind = models.IntegerField() 

而且我已經創建了兩個ModelForms對應：

//形式.py

class CreateDataItemForm(forms.ModelForm): 

    class Meta: 
     model = DataItem 
     exclude = ('owner',) 

    def save(self, user, commit=True): 
     item = super(CreateDataItemForm,self).save(commit=False) 
     item.owner = user 
     if commit: 
      item.save() 
     return item 


class CreateDataItemSetForm(forms.ModelForm): 

    class Meta: 
     model = DataItemSet 
     exclude = ('item',) 

    def save(self, parent, commit=True): 
     set = super(CreateDataItemSetForm,self).save(commit=False) 
     set.item = parent 
     if commit: 
      set.save() 
     return set 

在我看來，我試圖讓一個表單提交由DataItem擁有的新DataItem和1-n DataItemSet的創建。這裏的形式的輸出的一個示例：

而模板：

<form action="." method="post"> 
    {% csrf_token %} 
    <table> 
     {{ create_form.as_table }} 
    </table> 
    <table> 
     <tr> 
      <th>What to track:</th> 
      <td> 
       <select> 
        <option value="1">Number</option> 
        <option value="2">Currency ($)</option> 
        <option value="3">Date</option> 
        <option value="4">Day</option> 
        <option value="5">Time</option> 
       </select> 
      </td> 
      <td> 

      </td> 
     </tr> 
     <tr> 
      <th>What to track:</th> 
      <td> 
       <select> 
        <option value="1">Number</option> 
        <option value="2">Currency ($)</option> 
        <option value="3">Date</option> 
        <option value="4">Day</option> 
        <option value="5">Time</option> 
       </select> 
      </td> 
      <td> 
       <button type="button">+</button> 
      </td> 
     </tr> 
    </table> 
    <p> 
     <button type="submit">Create</button> 
    </p> 
</form> 

最後，該視圖：

// views.py

@login_required 
@csrf_protect 
def create_data_item(request): 
    create_form = CreateDataItemForm() 
    c = {'create_form':create_form} 
    c.update(csrf(request)) 
    if request.method == 'POST': 
     data = request.POST.copy() 
     form = CreateDataItemForm(data, instance=DataItem()) 
     item_sets = [CreateDataItemSetForm(request.POST, prefix=str(x), instance=DataItemSet()) for x in range(0,9)] 
     if form.is_valid(): 
      # create new data item 
      new_item = form.save(request.user) 
      #create new set of stuff to track 
      for item_set in item_sets: 
       new_item_set = item_set.save(new_item) 
      # return to the add entry page 
      return redirect('/add') 
    else: 
     return render_to_response('internal/create_data_item.html',c) 

我很想知道如何允許從t中動態提取0-n DataItemSets他form。我無法弄清楚它與ModelForm。

感謝您的幫助！

Answer 1

這就是model formsets - 特別是inline formsets - 的用途。