python - 如何禁用 MultipleChoiceField 中的复选框？

Question

我在表单中使用 MultipleChoiceField。它向我显示了带有复选框的 REQUIREMENTS_CHOICES 列表，用户可以在其中选择新需求并将其添加到数据库中。是否可以禁用数据库中已有的复选框(在我的情况下是要求)？假设我在数据库中有 A 和 C，所以我不需要它们。

tulpe中第一个值是需求符号，第二个值是需求名称。

模型.py:

class Requirement(models.Model):
    code = models.UUIDField(_('Code'), primary_key=True, default=uuid.uuid4, editable=False)
    symbol = models.CharField(_('Symbol'), max_length=250)
    name = models.CharField(_('Name'), max_length=250)

表单.py:

REQUIREMENTS_CHOICES = (
        ('A', 'Name A'),
        ('B', 'Name B'),
        ('C', 'Name C'),
        ('D', 'Name D'),
)


class RequirementAddForm(forms.ModelForm):
    symbol = forms.MultipleChoiceField(required=False, widget=forms.CheckboxSelectMultiple, choices=REQUIREMENTS_CHOICES,)

    class Meta:
        model = Requirement
        fields = ('symbol',)

views.py:

def requirement_add(request):
    data = dict()
    if request.method == 'POST':
        form = RequirementAddForm(request.POST)
        if form.is_valid():
            list = dict(REQUIREMENTS_CHOICES) # {'C': 'Name C', 'A': 'Name A', 'B': 'Name B'}
            symbols = form.cleaned_data.get('symbol') # ['A', 'B', 'C']
            requirement = form.save(commit=False)
            for symbol in symbols:
                requirement.symbol = symbol
                requirement.name = list[symbol]
                requirement.save()
            data['form_is_valid'] = True
            requirements = Requirement.objects.filter()
            context = {requirement': requirement, 'requirements': requirements}
            data['html_requirement'] = render_to_string('project/requirement_list.html', context)
        else:
            data['form_is_valid'] = False
    else:
        form = RequirementAddForm()
    context = {'form': form}
    data['html_requirement_form'] = render_to_string('project/requirement_add.html', context, request=request)
    return JsonResponse(data)

Answer 1

您可以在表单初始化时对其进行操作:

REQUIREMENTS_CHOICES = (
        ('A', 'Name A'),
        ('B', 'Name B'),
        ('C', 'Name C'),
        ('D', 'Name D'),
)


class RequirementAddForm(forms.ModelForm):
    def __init__(self, symbols='', *args, **kwargs):
        super(RequirementAddForm, self).__init__(*args, **kwargs)

        UPDATED_CHOICES = () # empty tuple
        for choice in REQUIREMENTS_CHOICES:
            if choice[1] not in symbols:
                UPDATED_CHOICES += (choice,) # adds choice as a tuple

        self.fields['symbol'] = forms.MultipleChoiceField(
                                    required=False,
                                    widget=forms.CheckboxSelectMultiple, 
                                    choices=UPDATED_CHOICES,
                                )

    class Meta:
        model = Requirement

上面发生了什么:

1. 当你初始化你的表单时
   (例如:form=RequirementAddForm(symbols=existing_symbols))，您可以向构造函数传递一个字符串，其中包含数据库中某个项目的现有符号。
2. __init__ 函数检查 symbols 中已经存在哪些选择，并相应地更新 UPDATED_CHOICES。
3. 一个名为 symbol 的字段从构造函数添加到表单中，它具有 UPDATED_CHOICES 选项。