如何在django inline_formset中为外键字段提供查询集？

Question

I have the below forms:

class Purchase_form(forms.ModelForm):
    class Meta:
        model  = Purchase
        fields = ('date','party_ac', 'purchase')
        widgets = {
            'date': DateInput(),
        }

    def __init__(self, *args, **kwargs):        
        self.Company = kwargs.pop('company', None)
        super(Purchase_form, self).__init__(*args, **kwargs)
        self.fields['date'].widget.attrs     = {'class': 'form-control',}
        self.fields['party_ac'].queryset = Ledger1.objects.filter(company = self.Company)  
        self.fields['purchase'].queryset = Ledger1.objects.filter(Company = self.Company)


class Stock_Totalform(forms.ModelForm):
    class Meta:
        model  = Stock_Total
        fields = ('stockitem')

    def __init__(self, *args, **kwargs):
        self.Company = kwargs.pop('Company', None)
        super(Stock_Totalform, self).__init__(*args, **kwargs)
        self.fields['stockitem'].widget.attrs = {'class': 'form-control select2',}
        self.fields['Total_p'].widget.attrs = {'class': 'form-control',}

Purchase_formSet = inlineformset_factory(Purchase, Stock_Total,
                                            form=Stock_Totalform, extra=6)

My models:

class Purchase(models.Model):
    user            = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE,null=True,blank=True)
    company         = models.ForeignKey(company,on_delete=models.CASCADE,null=True,blank=True)
    date            = models.DateField(default=datetime.date.today,blank=False, null=True)
    party_ac        = models.ForeignKey(Ledger1,on_delete=models.CASCADE,related_name='partyledger')
    purchase        = models.ForeignKey(Ledger1,on_delete=models.CASCADE,related_name='purchaseledger')



class Stock_Total(models.Model):
    user        = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE,null=True,blank=True)
    company     = models.ForeignKey(Company,on_delete=models.CASCADE,null=True,blank=True)
    purchases   = models.ForeignKey(Purchase,on_delete=models.CASCADE,null=True,blank=False,related_name='purchasetotal') 
    stockitem   = models.ForeignKey(Stockdata,on_delete=models.CASCADE,null=True,blank=True,related_name='purchasestock') 

I want to make a queryset for the inline form field stockitem that it will filter the result in the form according to request.user and company as I have done it for the normal Purchase_form (I have done it using get_form_kwargs(self) method in the views for normal form).

I am having a difficulty to do a queryset in inlineform.

I want to do something like this in my inline_form:

 self.fields['stockitem'].queryset = Stockdata.objects.filter(company = self.Company)  

As I have done in normal forms.

Any idea anyone how to do this?

Thank you

Answer 1

To filter a field in the formset you have to override the add_fields method.

class PurchaseFormSet(forms.BaseInlineFormSet):
    def __init__(self, *args, **kwargs):        
        self.company = kwargs.pop('company', None)
        super().__init__(*args, **kwargs)

    def add_fields(self, form, index):
        super().add_fields(form, index)
        form.fields['stockitem'].queryset = StockData.objects.filter(company=self.company)

Worth noting in your example you could filter the queryset in the child form's __init__ method. All of the form field attributes are also passed to the formset.