filter choices from Django models using ModelForm

Question

I have to send some data to my database where I have a phone object. For this I need to select the desired phone number and insert the desired information to the database. A requirement is to display the phone numbers that belongs to the current login user.
I use Django model named Phone and a modelForm named phoneForm.

class Phone(models.Model):
    user = models.ForeignKey(User)
    phone_num = models.ForeignKey(Sim, null=True)
    imei = models.CharField(max_length=30, primary_key=True)
    num_calls = models.CharField(max_length=20, null=True, blank=True)
    time_btwn_calls = models.CharField(max_length=20, null=True, blank=True)
    psap = models.CharField(max_length=30, null=True, blank=True)

class Sim(models.Model):
    phone_num = models.CharField(max_length=30, primary_key=True)
    pin = models.CharField(max_length=15)
    puk = models.CharField(max_length=15)

class phoneForm(ModelForm):

    class Meta:
        model = Phone
        fields = ['phone_num', 'num_calls', 'time_btwn_calls', 'psap']
        widgets = {'phone_num': Select(attrs={'class': 'form-control'}), 
                'num_calls': TextInput(attrs={'class': 'form-control'}),
                'time_btwn_calls': TextInput(attrs={'class': 'form-control'}), 
                'psap': TextInput(attrs={'class': 'form-control'})
                  }
        labels = {
                'phone_num': ('Select phone number'),
                'num_calls': ('Number of calls'),
                'time_btwn_calls': ('Time between calls'),
                'psap': ('PSAP'),
        }

        def __init__(self, *args, **kwargs):
            super(phoneForm, self).__init__(*args, **kwargs)
            self.queryset = Phone.objects.filter(user_id = request.user.id).values('phone_num')

How can I acces the database properly to filter the phone_num values that belongs to the current user and then set them in phone_num choices?

My template is:

<div class="row">
    <div class="col-md-6 col-sm-offset-3">
        <form method="post" action="" enctype="multipart/form-data">
            {% csrf_token %}  <!-- obligatorio para protegerse de ataques maliciosos -->
            {{ form.as_p }} <!-- pasamos la variable form y con as_p conseguimos <p> -->
            <button type="submit" class="btn btn-primary">Send to TCU</button>
        </form>
    </div>

And my view.py:

def phone_config(request):
    phone = Phone.objects.get(phone_num=611111111)

    if request.method == 'POST':
        form = phoneForm(request, request.POST, instance=phone)
        if form.is_valid():
            form.save()
            return redirect(reverse('gracias'))
    else:
        form = phoneForm(request, instance=tcu)
    return render(request, 'heroconfigurer/heroconfigurer.html', {'form': form})


def gracias_view(request):
    return render(request, 'heroconfigurer/gracias.html')

Answer 1

To modify the phone_num field in your form, you access self.fields['phone_num'] in your form's __init__ method.

class phoneForm(ModelForm):

    class Meta:
        model = Phone
        ...

    def __init__(self, user, *args, **kwargs):
        super(phoneForm, self).__init__(*args, **kwargs)
        phone_nums = Phone.objects.filter(user=user).values_list('phone_num', flat=True)
        self.fields['phone_num'].queryset = Sim.objects.filter(phone_num__in=phone_nums)

When you initialise the form in your view, you need to pass the user, e.g.

form = phoneForm(user, request.POST)

If that doesn't work, please explain why and show your Sim model.

Note a couple of other changes:

• No need to use values()
• If Sim.user is a foreign key, then you can simplify the filter to filter(user=request.user)
• The user has been added to the form's __init__ method.