ManyToManyフィールドのデータを保存する際の問題

Question

私は2を持つモーダルを持っています。ManyToManyField。フォームを保存しようとすると問題が発生します。なぜsave_m2m()メソッドは動作しませんか？

functionフィールドのフォームには、ModelChoiceFieldを、programフィールドには、ModelMultipleChoiceFieldを使用しています。

modals.py：

class Requirement(models.Model): 
    group_requirement = models.ForeignKey(GroupRequirement, on_delete=models.CASCADE) 

    function = models.ManyToManyField("Function") 
    program = models.ManyToManyField('Program') 

forms.py：

class RequirementForm(forms.ModelForm): 
    function = forms.ModelChoiceField(widget=Select2Widget(), queryset=Function.objects.none()) 
    program = forms.ModelMultipleChoiceField(widget=Select2MultipleWidget(), queryset=Program.objects.none()) 

    class Meta: 
     model = Requirement 
     fields = ('function', 'program') 

    def __init__(self, all_functions, all_programs, *args, **kwargs): 
     super(RequirementForm, self).__init__(*args, **kwargs) 
     self.fields['function'].queryset = all_functions 
     self.fields['program'].queryset = all_programs 

views.py：

def requirement_add(request, project_id, group_requirement_id): 
    group_requirement = get_object_or_404(GroupRequirement, pk=group_requirement_id) 

    all_functions = Function.objects.filter(project=project_id) 
    all_programs = Program.objects.filter(project=project_id) 

    if request.method == 'POST': 
     requirement_form = RequirementForm(data=request.POST, all_functions=all_functions, all_programs=all_programs) 
     if requirement_form.is_valid(): 
      requirement = requirement_form.save(commit=False) 
      requirement.group_requirement = group_requirement 
      requirement.save() 
      requirement_form.save_m2m() 

ERROR：

Traceback (most recent call last): 
    File "C:\Users\Nurzhan\AppData\Local\Programs\Python\Python35-32\lib\site-packages\django\core\handlers\exception.py", line 39, in inner 
    response = get_response(request) 
    File "C:\Users\Nurzhan\AppData\Local\Programs\Python\Python35-32\lib\site-packages\django\core\handlers\base.py", line 187, in _get_response 
    response = self.process_exception_by_middleware(e, request) 
    File "C:\Users\Nurzhan\AppData\Local\Programs\Python\Python35-32\lib\site-packages\django\core\handlers\base.py", line 185, in _get_response 
    response = wrapped_callback(request, *callback_args, **callback_kwargs) 
    File "C:\Users\Nurzhan\PycharmProjects\RMS\project\views.py", line 1397, in requirement_add 
    requirement_form.save_m2m() 
    File "C:\Users\Nurzhan\AppData\Local\Programs\Python\Python35-32\lib\site-packages\django\forms\models.py", line 436, in _save_m2m 
    f.save_form_data(self.instance, cleaned_data[f.name]) 
    File "C:\Users\Nurzhan\AppData\Local\Programs\Python\Python35-32\lib\site-packages\django\db\models\fields\related.py", line 1573, in save_form_data 
    getattr(instance, self.attname).set(data) 
    File "C:\Users\Nurzhan\AppData\Local\Programs\Python\Python35-32\lib\site-packages\django\db\models\fields\related_descriptors.py", line 928, in set 
    objs = tuple(objs) 
TypeError: 'Function' object is not iterable 

Answer 1

まあ私の問題は、私はModelChoiceFieldによってManyToManyFieldに一つのオブジェクトを保存しようとしたということでした。 ManyToManyFieldはクエリーセットを予期します。私は、フォームフィールドからデータを取得し、このコードによって、ビューに保存することにしました：

views.py：

function= requirement_form.cleaned_data['function'] 
programs = requirement_form.cleaned_data['programs'] 

requirement= requirement_form.save(commit=False) 

requirement.function.add(function) 
for program in programs: 
    requirement.program.add(program)