将表单外键限制为相关模型中的选择

Question

我正在创建一个表单，但卡在这个问题上。

我在商业模式中有几项业务。 每个企业都有自己的服务中的服务模型。 用户仅与一项业务相关联。 两者业务，服务都有关系。

我的挑战

我有一份服务申请表。 当我展示此服务请求模型表时，我只想显示客户/用户所属的 One Business 的服务。 请帮助我这怎么可能。 我认为它会像“实例 = 业务”。 我明白它不是那么简单。

例如：Business1 将“Cars”和“Motor Bikes”作为服务，Business2 将“指甲”和“Hair Spa”作为服务。 如果来自 Business1 的用户登录并打开服务请求表，她/他应该在服务选择下拉列表中只看到“汽车”和“摩托车”。

'''

    # class Service(models.Model):
class Business(models.Model):
    name = models.CharField(max_length=25)
    description = models.CharField(max_length=100)
    active = models.BooleanField(default=True)

class BusinessUser(models.Model):
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    business = models.ForeignKey(Business, on_delete=models.CASCADE, related_name='business')
    
class Services(models.Model):   
    business = models.ForeignKey(Business, on_delete=models.CASCADE, related_name='business_services')
    name = models.CharField(max_length=15)
    active = models.BooleanField(default=True)

class ServiceRequest(models.Model):
    business = models.ForeignKey(Business, on_delete=models.DO_NOTHING)
    service = models.ForeignKey(Service, on_delete=models.DO_NOTHING, blank=True)
    requester_name = models.CharField(max_length=15)

 class  ServiceRequestForm(forms.ModelForm):
     class Meta:
        model = ServiceRequest
        fields = '__all__'

def newServiceRequest(request):  //the view
    if request.method == 'GET':
        user = request.user
        business = user.business
        serviceRequestForm = ServiceRequestForm(instance=business)
        return render(request,'service.html', {'form':serviceRequestForm})

'''

Answer 1

一种方法是使用django-select2 。 请参阅此处的安装说明

然后在您的表单中，您可以执行以下操作：

 class  ServiceRequestForm(forms.ModelForm):
     class Meta:
        model = ServiceRequest
        fields = '__all__'
        widgets = {
            'business': ModelSelect2Widget(
                    model=Business,
                    attrs={'class': 'form-control', 'data-minimum-input-length': 0},
                    search_fields=['name__icontains'],
            ),
            'service': ModelSelect2Widget(
                    model=Services,
                    attrs={'class': 'form-control', 'data-minimum-input-length': 0},
                    search_fields=['name__icontains'],
                    dependent_fields={'business': 'business'},
            ),
        }

关键元素是dependent_fields选项。 在此处阅读更多相关信息

Answer 2

您可以通过当前的业务和更新queryset在ModelForm构造。

class  ServiceRequestForm(forms.ModelForm):

    def __init__(self, business, *args, **kw):
        super(ServiceRequestForm, self).__init__(*args, **kw)
        self.fields['business'].queryset = \
           self.fields['business'].queryset.filter(pk=business.pk)

    class Meta:
        model = ServiceRequest
        fields = '__all__'


def newServiceRequest(request):  # the view
    user = request.user
    business = user.business
    
    if request.method == 'POST':
        serviceRequestForm = ServiceRequestForm(business, data=request.POST)
        if (serviceRequestForm.is_valid()):
             serviceRequest = serviceRequestForm.save()
             # another stuff...
             # ... 
    else:
        serviceRequestForm = ServiceRequestForm(business)

    return render(request,'service.html', {'form':serviceRequestForm})