创建动态选择字段

Question

我在尝试了解如何在Django中创建动态选择字段时遇到了一些麻烦。我有一个模型设置类似：

class rider(models.Model):
     user = models.ForeignKey(User)
     waypoint = models.ManyToManyField(Waypoint)

class Waypoint(models.Model):
     lat = models.FloatField()
     lng = models.FloatField()

我想做的是创建一个选择字段whos的值是与该骑手相关联的航点（将是登录的人）。

目前，我以如下形式覆盖init：

class waypointForm(forms.Form):
     def __init__(self, *args, **kwargs):
          super(joinTripForm, self).__init__(*args, **kwargs)
          self.fields['waypoints'] = forms.ChoiceField(choices=[ (o.id, str(o)) for o in Waypoint.objects.all()])

但是所有要做的就是列出所有路标，它们与任何特定的骑手都没有关联。有任何想法吗？谢谢。

Answer 1

你可以通过将用户传递给表单init来过滤航点

class waypointForm(forms.Form):
    def __init__(self, user, *args, **kwargs):
        super(waypointForm, self).__init__(*args, **kwargs)
        self.fields['waypoints'] = forms.ChoiceField(
            choices=[(o.id, str(o)) for o in Waypoint.objects.filter(user=user)]
        )

启动表单时从你的角度来看

form = waypointForm(user)

在模型形式的情况下

class waypointForm(forms.ModelForm):
    def __init__(self, user, *args, **kwargs):
        super(waypointForm, self).__init__(*args, **kwargs)
        self.fields['waypoints'] = forms.ModelChoiceField(
            queryset=Waypoint.objects.filter(user=user)
        )

    class Meta:
        model = Waypoint