ModelForm field not showing

Question

I know this is very simple but I've been at this for longer it should be and cannot find what I did wrong here.

I have a modelform where I want to include the primary key, and the name:

class ModbusDevice(models.Model):
    ixModbusDevice = models.AutoField(primary_key=True)
    sModbusName = models.CharField(verbose_name='Device Name',max_length=100)

class BACnetModbusDeviceForm(ModelForm):
    class Meta:
        model = ModbusDevice
        fields = ['ixModbusDevice', 'sModbusName']
        widgets = {
                'ixModbusDevice' : TextInput(),
                'sModbusName' : TextInput(attrs={'class': 'form-control', 'readonly': True}),
            }

then in my view I have: (BACnetModbusContainer is a custom class)

class BACnetModbusContainer:
    modbus_devices = None
    bacnet_devices = None

method:

modbus_devices = ModbusDevice.objects.all()

devices = []

for idx,device in enumerate(modbus_devices):
    container = BACnetModbusContainer()
    container.bacnet_devices = BACnetDeviceForm(prefix="bacnet_" + str(idx))
    container.modbus_devices = BACnetModbusDeviceForm(instance=device, prefix="modbus_" + str(idx))
    devices.append(container)

return render(
    request,
    'app/create_bacnet.html',
    context_instance = RequestContext(request,
    {
        'title':'Create BACnet Device',
        'tag': 'create_bacnet',
        'devices': devices
    })
)

then in my template:

{% for device in devices %}
    <tr>
        <td>
            {{ device.modbus_devices.sModbusName }}
            {{ device.modbus_devices.ixModbusDevice }}
        </td>
    </tr>
{% endfor %}

Why is my ixModbusDevice not showing?

Answer 1

Because it's an AutoField. Your can't set those; they are automatically assigned by the database, hence the name. Therefore there's no point in showing then on the form.

Answer 2

Try change the return to :

return render(
    request,
    'app/create_bacnet.html',
    {
         'title':'Create BACnetDevice',
         'tag':'create_bacnet',
         'devices': devices
    }
)

render() is the same as a call to render_to_response() with a context_instance argument that forces the use of a RequestContext.

Render Shortcut

Answer 3

managed to skip the rendering. I'm able to access the primary key via the "inital" attribute when I'm iterating all the devices:

{{ device.modbus_devices.initial.ixModbusDevice }}