python - 我无法从 django ModelForm 访问反向多对多字段
问题描述
我有两个实体,它们之间存在多对多关系。ProcessModel 具有 RouteModel 的 ManyToManyField 并创建了反向关系“进程”。我已经定义了两个 ModelForm,但我无法从路由表单访问反向多对多关系“进程”。保存路由表单的视图不显示流程字段。如何显示反向多对多字段并使用表单保存信息。这是我的代码
class ProcessModel(models.Model):
name = models.CharField(verbose_name="nombre", max_length=50, blank=False, null=False)
code = models.CharField(verbose_name="Código", max_length=50, blank=True, null=True, unique=True)
routes = models.ManyToManyField("RouteModel", verbose_name="lista de rutas", related_name="processes", blank=True)
class RouteModel(models.Model):
name = models.CharField(verbose_name="Nombre", max_length=50, blank=False, null=False)
route_type_id = models.ForeignKey("RouteTypeModel", verbose_name="Tipo",
blank=True, null=True, on_delete=models.SET_NULL,
related_name="routes")
start_date = models.DateField(verbose_name="Fecha inicio")
end_date = models.DateField(verbose_name="Fecha inicio")
from django_select2.forms import ModelSelect2Widget, ModelSelect2MultipleWidget
class ProcessForm(forms.ModelForm):
class Meta:
model = ProcessModel
exclude = ('id',)
widgets = {
'name':forms.TextInput(attrs={'class': 'form-control'}),
'code':forms.TextInput(attrs={'class': 'form-control'}),
'routes': ModelSelect2MultipleWidget(model=RouteModel, queryset=RouteModel.objects.filter(),
search_fields=['name__icontains'],
attrs={'style': 'width: 100%;'}),
}
class RouteForm(forms.ModelForm):
class Meta:
model = RouteModel
exclude = ("id",)
widgets = {
'name':forms.TextInput(attrs={'class': 'form-control'}),
'route_type_id': forms.Select(attrs={'class': 'form-control'}),
'start_date' :forms.DateInput(attrs={'class': 'form-control datepicker', 'autocomplete': 'off'}),
'end_date' :forms.DateInput(attrs={'class': 'form-control datepicker', 'autocomplete': 'off'}),
'processes': ModelSelect2MultipleWidget(model=ProcessModel, queryset=ProcessModel.objects.filter(),
search_fields=['name__icontains'],
attrs={'style': 'width: 100%;'}),
}
解决方案
我刚刚找到了解决方案,我不得不添加进程字段并覆盖“init”和“save”函数。这是RouteForm的定义
class RouteForm(forms.ModelForm):
processes = forms.ModelMultipleChoiceField(
queryset=ProcessModel.objects.all(),
widget=ModelSelect2MultipleWidget(model=ProcessModel, queryset=ProcessModel.objects.filter(),
search_fields=['name__icontains'],
attrs={'style': 'width: 100%;'}),)
class Meta:
model = RouteModel
exclude = ("id",)
widgets = {
'name':forms.TextInput(attrs={'class': 'form-control'}),
'route_geom': LeafletWidget(),
'route_type_id': forms.Select(attrs={'class': 'form-control'}),
'start_date' :forms.DateInput(attrs={'class': 'form-control datepicker', 'autocomplete': 'off'}),
'end_date' :forms.DateInput(attrs={'class': 'form-control datepicker', 'autocomplete': 'off'}), }
def __init__(self, *args, **kwargs):
super(RouteForm, self).__init__(*args, **kwargs)
# Here we fetch the currently related projects into the field,
# so that they will display in the form.
if self.instance.id:
self.fields['processes'].initial = self.instance.processes.all(
).values_list('id', flat=True)
def save(self, *args, **kwargs):
instance = super(RouteForm, self).save(*args, **kwargs)
# Here we save the modified project selection back into the database
instance.processes.set(self.cleaned_data['processes'])
return instance
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