多选择的复选框无法在Django中创建对象

Question

我有一个应用程序，人们可以在其中宣告事情，在声明中他们可以说是谁在场，所以他们必须付款，只能付款。编辑功能有效，但FileDecla却没有。 行不通的部分是目前的人。当我打印出席的人（通过print（request.post））在保存声明之前，它会给所有选择的人，但后来却没有保存他们，当我打印（decla.present）时，我会得到 - ＆gt;没有

。

​

class Decla(models.Model):
    owner = models.ForeignKey(Lid, on_delete=models.CASCADE)
    event = models.ForeignKey(Event, on_delete=models.SET_NULL, null=True, blank=True)
    content = models.TextField(max_length=50)
    total = models.FloatField()
    present = models.ManyToManyField(Lid, related_name="present_leden")
    receipt = models.ImageField(
        upload_to="declas/", null=True, blank=True
    )  ## this will need to be put back to nothing when it ends
    verwerkt = models.BooleanField(default=False)

​

@login_required(login_url="login")
def fileDecla(request):
    form = DeclaForm()
    if request.method == "POST":
        print(1, request.POST)
        form = DeclaForm(request.POST, request.FILES)
        if form.is_valid():
            # print(form)
            decla = form.save(commit=False)
            decla.owner = request.user.lid
            # i tried this line bellow but it didnt work
            # decla.present.set(request.POST["present"])
            decla.save()
            messages.info(request, "Decla was created")
            return redirect("agenda")
    context = {
        "form": form,
        "stand": Stand.objects.get(owner_id=request.user.lid.id).amount,
    }
    return render(request, "finance/decla_form.html", context)


@login_required(login_url="login")
def editDecla(request, pk):
    decla = Decla.objects.get(id=pk)
    form = DeclaForm(instance=decla)
    if request.method == "POST":
        print(request.POST)

        form = DeclaForm(request.POST, request.FILES, instance=decla)
        if form.is_valid():
            decla = form.save()
            messages.info(request, "Decla was edited")
            return redirect(request.GET["next"] if "next" in request.GET else "agenda")
    context = {
        "form": form,
        "stand": Stand.objects.get(owner_id=request.user.lid.id).amount,
    }
    return render(request, "finance/decla_form.html", context)

​

from django import forms
from django.forms import ModelForm
from django.forms.widgets import NumberInput, CheckboxSelectMultiple
from .models import Decla


class DeclaForm(ModelForm):
    class Meta:
        model = Decla
        fields = "__all__"
        exclude = ["owner", "id"]
        widgets = {
            "present": CheckboxSelectMultiple(),
        }

    def __init__(self, *args, **kwargs):
        super(DeclaForm, self).__init__(*args, **kwargs)
        for name, field in self.fields.items():
            if not name in ["verwerkt", "present"]:
                field.widget.attrs.update({"class": "input"})
            # also tried this
            # elif name == "present":
            #     field.widget.attrs.update({"class": "CheckboxSelectMultiple"})
            else:
                field.widget.attrs.update({"class": "checkbox"})

Answer 1

这是 docs ：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：：

使用commit = false的另一个副作用在您的模型具有
与另一个模型的多一关系。如果您的模型有一个
多一关系的关系，您在保存一个时指定commit = false
表单，Django无法立即保存表单数据
多一的关系。这是因为不可能保存
一个实例的多一数据数据，直到实例存在于
数据库。

要解决此问题，每次您使用
commit = false，django添加了一个save_m2m（）方法
子类。手动保存了由
表单，您可以调用save_m2m（）来保存多一对多的表单数据。

据此，添加save_m2m（）在调用exta.save（）后将解决您的问题：

@login_required(login_url="login")
def fileDecla(request):
    form = DeclaForm()
    if request.method == "POST":
        print(1, request.POST)
        form = DeclaForm(request.POST, request.FILES)
        if form.is_valid():
            # print(form)
            decla = form.save(commit=False)
            decla.owner = request.user.lid
            # i tried this line bellow but it didnt work
            # decla.present.set(request.POST["present"])
            decla.save()
            form.save_m2m()
            messages.info(request, "Decla was created")
            return redirect("agenda")
    context = {
        "form": form,
        "stand": Stand.objects.get(owner_id=request.user.lid.id).amount,
    }
    return render(request, "finance/decla_form.html", context)

但是，这似乎是一个混乱的解决方案。参见 Antpattern 有关更多信息。

我的建议是这样做：

@login_required(login_url="login")
def fileDecla(request):
    form = DeclaForm()
    if request.method == "POST":
        print(1, request.POST)
        form = DeclaForm(request.POST, request.FILES)
        if form.is_valid():
            # This seems like a much cleaner solution and it should resolve your problem
            form.instance.owner = request.user.lid
            decla = form.save()
            messages.info(request, "Decla was created")
            return redirect("agenda")
    context = {
        "form": form,
        "stand": Stand.objects.get(owner_id=request.user.lid.id).amount,
    }
    return render(request, "finance/decla_form.html", context)

免责声明：未经测试的代码。让我知道您是否有错误。