Closes #1167: Introduced ChainedModelChoiceFields

netbox/circuits/forms.py

@@ -5,8 +5,8 @@ from dcim.models import Site, Device, Interface, Rack, VIRTUAL_IFACE_TYPES
 from extras.forms import CustomFieldForm, CustomFieldBulkEditForm, CustomFieldFilterForm
 from tenancy.models import Tenant
 from utilities.forms import (
-    APISelect, BootstrapMixin, BulkImportForm, CommentField, CSVDataField, FilterChoiceField, Livesearch, SmallTextarea,
-    SlugField,
+    APISelect, BootstrapMixin, BulkImportForm, ChainedFieldsMixin, ChainedModelChoiceField, CommentField, CSVDataField,
+    FilterChoiceField, Livesearch, SmallTextarea, SlugField,
 )
 
 from .models import Circuit, CircuitTermination, CircuitType, Provider
@@ -152,15 +152,16 @@ class CircuitFilterForm(BootstrapMixin, CustomFieldFilterForm):
 # Circuit terminations
 #
 
-class CircuitTerminationForm(BootstrapMixin, forms.ModelForm):
+class CircuitTerminationForm(BootstrapMixin, ChainedFieldsMixin, forms.ModelForm):
     site = forms.ModelChoiceField(
         queryset=Site.objects.all(),
         widget=forms.Select(
             attrs={'filter-for': 'rack'}
         )
     )
-    rack = forms.ModelChoiceField(
+    rack = ChainedModelChoiceField(
         queryset=Rack.objects.all(),
+        chains={'site': 'site'},
         required=False,
         label='Rack',
         widget=APISelect(
@@ -168,8 +169,9 @@ class CircuitTerminationForm(BootstrapMixin, forms.ModelForm):
             attrs={'filter-for': 'device', 'nullable': 'true'}
         )
     )
-    device = forms.ModelChoiceField(
+    device = ChainedModelChoiceField(
         queryset=Device.objects.all(),
+        chains={'site': 'site', 'rack': 'rack'},
         required=False,
         label='Device',
         widget=APISelect(
@@ -187,8 +189,11 @@ class CircuitTerminationForm(BootstrapMixin, forms.ModelForm):
             field_to_update='device'
         )
     )
-    interface = forms.ModelChoiceField(
-        queryset=Interface.objects.all(),
+    interface = ChainedModelChoiceField(
+        queryset=Interface.objects.exclude(form_factor__in=VIRTUAL_IFACE_TYPES).select_related(
+            'circuit_termination', 'connected_as_a', 'connected_as_b'
+        ),
+        chains={'device': 'device'},
         required=False,
         label='Interface',
         widget=APISelect(
@@ -210,51 +215,16 @@ class CircuitTerminationForm(BootstrapMixin, forms.ModelForm):
             'term_side': forms.HiddenInput(),
         }
 
-    def __init__(self, *args, **kwargs):
-
-        super(CircuitTerminationForm, self).__init__(*args, **kwargs)
-
-        # If an interface has been assigned, initialize rack and device
-        if self.instance.interface:
-            self.initial['rack'] = self.instance.interface.device.rack
-            self.initial['device'] = self.instance.interface.device
-
-        # Limit rack choices
-        if self.is_bound:
-            self.fields['rack'].queryset = Rack.objects.filter(site__pk=self.data['site'])
-        elif self.initial.get('site'):
-            self.fields['rack'].queryset = Rack.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['rack'].choices = []
-
-        # Limit device choices
-        if self.is_bound and self.data.get('rack'):
-            self.fields['device'].queryset = Device.objects.filter(rack=self.data['rack'])
-        elif self.initial.get('rack'):
-            self.fields['device'].queryset = Device.objects.filter(rack=self.initial['rack'])
-        else:
-            self.fields['device'].choices = []
-
-        # Limit interface choices
-        if self.is_bound and self.data.get('device'):
-            interfaces = Interface.objects.filter(device=self.data['device']).exclude(
-                form_factor__in=VIRTUAL_IFACE_TYPES
-            ).select_related(
-                'circuit_termination', 'connected_as_a', 'connected_as_b'
-            )
-            self.fields['interface'].widget.attrs['initial'] = self.data.get('interface')
-        elif self.initial.get('device'):
-            interfaces = Interface.objects.filter(device=self.initial['device']).exclude(
-                form_factor__in=VIRTUAL_IFACE_TYPES
-            ).select_related(
-                'circuit_termination', 'connected_as_a', 'connected_as_b'
-            )
-            self.fields['interface'].widget.attrs['initial'] = self.initial.get('interface')
-        else:
-            interfaces = []
+    def __init__(self, instance=None, initial=None, *args, **kwargs):
+
+        # Initialize helper selectors
+        if instance and instance.interface is not None:
+            initial['rack'] = instance.interface.device.rack
+            initial['device'] = instance.interface.device
+
+        super(CircuitTerminationForm, self).__init__(instance=instance, initial=initial, *args, **kwargs)
+
+        # Mark connected interfaces as disabled
         self.fields['interface'].choices = [
-            (iface.id, {
-                'label': iface.name,
-                'disabled': iface.is_connected and iface.id != self.fields['interface'].widget.attrs.get('initial'),
-            }) for iface in interfaces
+            (iface.id, {'label': iface.name, 'disabled': iface.is_connected}) for iface in self.fields['interface'].queryset
         ]

netbox/dcim/forms.py

@@ -11,8 +11,9 @@ from ipam.models import IPAddress
 from tenancy.models import Tenant
 from utilities.forms import (
     APISelect, add_blank_choice, ArrayFieldSelectMultiple, BootstrapMixin, BulkEditForm, BulkEditNullBooleanSelect,
-    BulkImportForm, CommentField, CSVDataField, ExpandableNameField, FilterChoiceField, FlexibleModelChoiceField,
-    Livesearch, SelectWithDisabled, SmallTextarea, SlugField, FilterTreeNodeMultipleChoiceField,
+    BulkImportForm, ChainedFieldsMixin, ChainedModelChoiceField, CommentField, CSVDataField, ExpandableNameField,
+    FilterChoiceField, FlexibleModelChoiceField, Livesearch, SelectWithDisabled, SmallTextarea, SlugField,
+    FilterTreeNodeMultipleChoiceField,
 )
 
 from .formfields import MACAddressFormField
@@ -184,16 +185,23 @@ class RackRoleForm(BootstrapMixin, forms.ModelForm):
 # Racks
 #
 
-class RackForm(BootstrapMixin, CustomFieldForm):
-    group = forms.ModelChoiceField(queryset=RackGroup.objects.all(), required=False, label='Group', widget=APISelect(
-        api_url='/api/dcim/rack-groups/?site_id={{site}}',
-    ))
+class RackForm(BootstrapMixin, ChainedFieldsMixin, CustomFieldForm):
+    group = ChainedModelChoiceField(
+        queryset=RackGroup.objects.all(),
+        chains={'site': 'site'},
+        required=False,
+        widget=APISelect(
+            api_url='/api/dcim/rack-groups/?site_id={{site}}',
+        )
+    )
     comments = CommentField()
 
     class Meta:
         model = Rack
-        fields = ['site', 'group', 'name', 'facility_id', 'tenant', 'role', 'type', 'width', 'u_height', 'desc_units',
-                  'comments']
+        fields = [
+            'site', 'group', 'name', 'facility_id', 'tenant', 'role', 'type', 'width', 'u_height', 'desc_units',
+            'comments',
+        ]
         help_texts = {
             'site': "The site at which the rack exists",
             'name': "Organizational rack name",
@@ -204,18 +212,6 @@ class RackForm(BootstrapMixin, CustomFieldForm):
             'site': forms.Select(attrs={'filter-for': 'group'}),
         }
 
-    def __init__(self, *args, **kwargs):
-
-        super(RackForm, self).__init__(*args, **kwargs)
-
-        # Limit rack group choices
-        if self.is_bound and self.data.get('site'):
-            self.fields['group'].queryset = RackGroup.objects.filter(site__pk=self.data['site'])
-        elif self.initial.get('site'):
-            self.fields['group'].queryset = RackGroup.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['group'].choices = []
-
 
 class RackFromCSVForm(forms.ModelForm):
     site = forms.ModelChoiceField(queryset=Site.objects.all(), to_field_name='name',
@@ -538,25 +534,46 @@ class PlatformForm(BootstrapMixin, forms.ModelForm):
 # Devices
 #
 
-class DeviceForm(BootstrapMixin, CustomFieldForm):
-    site = forms.ModelChoiceField(queryset=Site.objects.all(), widget=forms.Select(attrs={'filter-for': 'rack'}))
-    rack = forms.ModelChoiceField(
-        queryset=Rack.objects.all(), required=False, widget=APISelect(
+class DeviceForm(BootstrapMixin, ChainedFieldsMixin, CustomFieldForm):
+    site = forms.ModelChoiceField(
+        queryset=Site.objects.all(),
+        widget=forms.Select(
+            attrs={'filter-for': 'rack'}
+        )
+    )
+    rack = ChainedModelChoiceField(
+        queryset=Rack.objects.all(),
+        chains={'site': 'site'},
+        required=False,
+        widget=APISelect(
             api_url='/api/dcim/racks/?site_id={{site}}',
             display_field='display_name',
             attrs={'filter-for': 'position'}
         )
     )
     position = forms.TypedChoiceField(
-        required=False, empty_value=None, help_text="The lowest-numbered unit occupied by the device",
-        widget=APISelect(api_url='/api/dcim/racks/{{rack}}/units/?face={{face}}', disabled_indicator='device')
+        required=False,
+        empty_value=None,
+        help_text="The lowest-numbered unit occupied by the device",
+        widget=APISelect(
+            api_url='/api/dcim/racks/{{rack}}/units/?face={{face}}',
+            disabled_indicator='device'
+        )
     )
     manufacturer = forms.ModelChoiceField(
-        queryset=Manufacturer.objects.all(), widget=forms.Select(attrs={'filter-for': 'device_type'})
+        queryset=Manufacturer.objects.all(),
+        widget=forms.Select(
+            attrs={'filter-for': 'device_type'}
+        )
     )
-    device_type = forms.ModelChoiceField(
-        queryset=DeviceType.objects.all(), label='Device type',
-        widget=APISelect(api_url='/api/dcim/device-types/?manufacturer_id={{manufacturer}}', display_field='model')
+    device_type = ChainedModelChoiceField(
+        queryset=DeviceType.objects.all(),
+        chains={'manufacturer': 'manufacturer'},
+        label='Device type',
+        widget=APISelect(
+            api_url='/api/dcim/device-types/?manufacturer_id={{manufacturer}}',
+            display_field='model'
+        )
     )
     comments = CommentField()
 
@@ -572,18 +589,17 @@ class DeviceForm(BootstrapMixin, CustomFieldForm):
         }
         widgets = {
             'face': forms.Select(attrs={'filter-for': 'position'}),
-            'manufacturer': forms.Select(attrs={'filter-for': 'device_type'}),
         }
 
-    def __init__(self, *args, **kwargs):
+    def __init__(self, instance=None, initial=None, *args, **kwargs):
 
-        super(DeviceForm, self).__init__(*args, **kwargs)
+        # Initialize helper selections
+        if instance and instance.device_type is not None:
+            initial['manufacturer'] = instance.device_type.manufacturer
 
-        if self.instance.pk:
+        super(DeviceForm, self).__init__(instance=instance, initial=initial, *args, **kwargs)
 
-            # Initialize helper selections
-            self.initial['site'] = self.instance.site
-            self.initial['manufacturer'] = self.instance.device_type.manufacturer
+        if self.instance.pk:
 
             # Compile list of choices for primary IPv4 and IPv6 addresses
             for family in [4, 6]:
@@ -607,14 +623,6 @@ class DeviceForm(BootstrapMixin, CustomFieldForm):
             self.fields['primary_ip6'].choices = []
             self.fields['primary_ip6'].widget.attrs['readonly'] = True
 
-        # Limit rack choices
-        if self.is_bound and self.data.get('site'):
-            self.fields['rack'].queryset = Rack.objects.filter(site__pk=self.data['site'])
-        elif self.initial.get('site'):
-            self.fields['rack'].queryset = Rack.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['rack'].choices = []
-
         # Rack position
         pk = self.instance.pk if self.instance.pk else None
         try:
@@ -635,16 +643,6 @@ class DeviceForm(BootstrapMixin, CustomFieldForm):
             }) for p in position_choices
         ]
 
-        # Limit device_type choices
-        if self.is_bound:
-            self.fields['device_type'].queryset = DeviceType.objects.filter(manufacturer__pk=self.data['manufacturer'])\
-                .select_related('manufacturer')
-        elif self.initial.get('manufacturer'):
-            self.fields['device_type'].queryset = DeviceType.objects.filter(manufacturer=self.initial['manufacturer'])\
-                .select_related('manufacturer')
-        else:
-            self.fields['device_type'].choices = []
-
         # Disable rack assignment if this is a child device installed in a parent device
         if pk and self.instance.device_type.is_child_device and hasattr(self.instance, 'parent_bay'):
             self.fields['site'].disabled = True
@@ -940,21 +938,23 @@ class ConsoleConnectionImportForm(BootstrapMixin, BulkImportForm):
         self.cleaned_data['csv'] = connection_list
 
 
-class ConsolePortConnectionForm(BootstrapMixin, forms.ModelForm):
+class ConsolePortConnectionForm(BootstrapMixin, ChainedFieldsMixin, forms.ModelForm):
     site = forms.ModelChoiceField(
         queryset=Site.objects.all(),
         widget=forms.HiddenInput(),
     )
-    rack = forms.ModelChoiceField(
+    rack = ChainedModelChoiceField(
         queryset=Rack.objects.all(),
+        chains={'site': 'site'},
         label='Rack',
         required=False,
         widget=forms.Select(
             attrs={'filter-for': 'console_server', 'nullable': 'true'}
         )
     )
-    console_server = forms.ModelChoiceField(
-        queryset=Device.objects.all(),
+    console_server = ChainedModelChoiceField(
+        queryset=Device.objects.filter(device_type__is_console_server=True),
+        chains={'site': 'site', 'rack': 'rack'},
         label='Console Server',
         required=False,
         widget=APISelect(
@@ -972,8 +972,9 @@ class ConsolePortConnectionForm(BootstrapMixin, forms.ModelForm):
             field_to_update='console_server',
         )
     )
-    cs_port = forms.ModelChoiceField(
+    cs_port = ChainedModelChoiceField(
         queryset=ConsoleServerPort.objects.all(),
+        chains={'device': 'console_server'},
         label='Port',
         widget=APISelect(
             api_url='/api/dcim/console-server-ports/?device_id={{console_server}}',
@@ -996,32 +997,6 @@ class ConsolePortConnectionForm(BootstrapMixin, forms.ModelForm):
         if not self.instance.pk:
             raise RuntimeError("ConsolePortConnectionForm must be initialized with an existing ConsolePort instance.")
 
-        # Initialize rack choices if site is set
-        if self.initial.get('site'):
-            self.fields['rack'].queryset = Rack.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['rack'].choices = []
-
-        # Initialize console_server choices if rack or site is set
-        if self.initial.get('rack'):
-            self.fields['console_server'].queryset = Device.objects.filter(
-                rack=self.initial['rack'], device_type__is_console_server=True
-            )
-        elif self.initial.get('site'):
-            self.fields['console_server'].queryset = Device.objects.filter(
-                site=self.initial['site'], rack__isnull=True, device_type__is_console_server=True
-            )
-        else:
-            self.fields['console_server'].choices = []
-
-        # Initialize CS port choices if console_server is set
-        if self.initial.get('console_server'):
-            self.fields['cs_port'].queryset = ConsoleServerPort.objects.filter(
-                device=self.initial['console_server']
-            )
-        else:
-            self.fields['cs_port'].choices = []
-
 
 #
 # Console server ports
@@ -1041,21 +1016,23 @@ class ConsoleServerPortCreateForm(DeviceComponentForm):
     name_pattern = ExpandableNameField(label='Name')
 
 
-class ConsoleServerPortConnectionForm(BootstrapMixin, forms.Form):
+class ConsoleServerPortConnectionForm(BootstrapMixin, ChainedFieldsMixin, forms.Form):
     site = forms.ModelChoiceField(
         queryset=Site.objects.all(),
         widget=forms.HiddenInput(),
     )
-    rack = forms.ModelChoiceField(
+    rack = ChainedModelChoiceField(
         queryset=Rack.objects.all(),
+        chains={'site': 'site'},
         label='Rack',
         required=False,
         widget=forms.Select(
             attrs={'filter-for': 'device', 'nullable': 'true'}
         )
     )
-    device = forms.ModelChoiceField(
+    device = ChainedModelChoiceField(
         queryset=Device.objects.all(),
+        chains={'site': 'site', 'rack': 'rack'},
         label='Device',
         required=False,
         widget=APISelect(
@@ -1073,8 +1050,9 @@ class ConsoleServerPortConnectionForm(BootstrapMixin, forms.Form):
             field_to_update='device'
         )
     )
-    port = forms.ModelChoiceField(
+    port = ChainedModelChoiceField(
         queryset=ConsolePort.objects.all(),
+        chains={'device': 'device'},
         label='Port',
         widget=APISelect(
             api_url='/api/dcim/console-ports/?device_id={{device}}',
@@ -1096,30 +1074,6 @@ class ConsoleServerPortConnectionForm(BootstrapMixin, forms.Form):
             'connection_status': 'Status',
         }
 
-    def __init__(self, *args, **kwargs):
-
-        super(ConsoleServerPortConnectionForm, self).__init__(*args, **kwargs)
-
-        # Initialize rack choices if site is set
-        if self.initial.get('site'):
-            self.fields['rack'].queryset = Rack.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['rack'].choices = []
-
-        # Initialize device choices if rack or site is set
-        if self.initial.get('rack'):
-            self.fields['device'].queryset = Device.objects.filter(rack=self.initial['rack'])
-        elif self.initial.get('site'):
-            self.fields['device'].queryset = Device.objects.filter(site=self.initial['site'], rack__isnull=True)
-        else:
-            self.fields['device'].choices = []
-
-        # Initialize port choices if device is set
-        if self.initial.get('device'):
-            self.fields['port'].queryset = ConsolePort.objects.filter(device=self.initial['device'])
-        else:
-            self.fields['port'].choices = []
-
 
 #
 # Power ports
@@ -1211,18 +1165,20 @@ class PowerConnectionImportForm(BootstrapMixin, BulkImportForm):
         self.cleaned_data['csv'] = connection_list
 
 
-class PowerPortConnectionForm(BootstrapMixin, forms.ModelForm):
+class PowerPortConnectionForm(BootstrapMixin, ChainedFieldsMixin, forms.ModelForm):
     site = forms.ModelChoiceField(queryset=Site.objects.all(), widget=forms.HiddenInput())
-    rack = forms.ModelChoiceField(
+    rack = ChainedModelChoiceField(
         queryset=Rack.objects.all(),
+        chains={'site': 'site'},
         label='Rack',
         required=False,
         widget=forms.Select(
             attrs={'filter-for': 'pdu', 'nullable': 'true'}
         )
     )
-    pdu = forms.ModelChoiceField(
+    pdu = ChainedModelChoiceField(
         queryset=Device.objects.all(),
+        chains={'site': 'site', 'rack': 'rack'},
         label='PDU',
         required=False,
         widget=APISelect(
@@ -1240,8 +1196,9 @@ class PowerPortConnectionForm(BootstrapMixin, forms.ModelForm):
             field_to_update='pdu'
         )
     )
-    power_outlet = forms.ModelChoiceField(
+    power_outlet = ChainedModelChoiceField(
         queryset=PowerOutlet.objects.all(),
+        chains={'device': 'device'},
         label='Outlet',
         widget=APISelect(
             api_url='/api/dcim/power-outlets/?device_id={{pdu}}',
@@ -1264,30 +1221,6 @@ class PowerPortConnectionForm(BootstrapMixin, forms.ModelForm):
         if not self.instance.pk:
             raise RuntimeError("PowerPortConnectionForm must be initialized with an existing PowerPort instance.")
 
-        # Initialize rack choices if site is set
-        if self.initial.get('site'):
-            self.fields['rack'].queryset = Rack.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['rack'].choices = []
-
-        # Initialize pdu choices if rack or site is set
-        if self.initial.get('rack'):
-            self.fields['pdu'].queryset = Device.objects.filter(
-                rack=self.initial['rack'], device_type__is_pdu=True
-            )
-        elif self.initial.get('site'):
-            self.fields['pdu'].queryset = Device.objects.filter(
-                site=self.initial['site'], rack__isnull=True, device_type__is_pdu=True
-            )
-        else:
-            self.fields['pdu'].choices = []
-
-        # Initialize power outlet choices if pdu is set
-        if self.initial.get('pdu'):
-            self.fields['power_outlet'].queryset = PowerOutlet.objects.filter(device=self.initial['pdu'])
-        else:
-            self.fields['power_outlet'].choices = []
-
 
 #
 # Power outlets
@@ -1307,21 +1240,23 @@ class PowerOutletCreateForm(DeviceComponentForm):
     name_pattern = ExpandableNameField(label='Name')
 
 
-class PowerOutletConnectionForm(BootstrapMixin, forms.Form):
+class PowerOutletConnectionForm(BootstrapMixin, ChainedFieldsMixin, forms.Form):
     site = forms.ModelChoiceField(
         queryset=Site.objects.all(),
         widget=forms.HiddenInput()
     )
-    rack = forms.ModelChoiceField(
+    rack = ChainedModelChoiceField(
         queryset=Rack.objects.all(),
+        chains={'site': 'site'},
         label='Rack',
         required=False,
         widget=forms.Select(
             attrs={'filter-for': 'device', 'nullable': 'true'}
         )
     )
-    device = forms.ModelChoiceField(
+    device = ChainedModelChoiceField(
         queryset=Device.objects.all(),
+        chains={'site': 'site', 'rack': 'rack'},
         label='Device',
         required=False,
         widget=APISelect(
@@ -1339,8 +1274,9 @@ class PowerOutletConnectionForm(BootstrapMixin, forms.Form):
             field_to_update='device'
         )
     )
-    port = forms.ModelChoiceField(
+    port = ChainedModelChoiceField(
         queryset=PowerPort.objects.all(),
+        chains={'device': 'device'},
         label='Port',
         widget=APISelect(
             api_url='/api/dcim/power-ports/?device_id={{device}}',
@@ -1362,30 +1298,6 @@ class PowerOutletConnectionForm(BootstrapMixin, forms.Form):
             'connection_status': 'Status',
         }
 
-    def __init__(self, *args, **kwargs):
-
-        super(PowerOutletConnectionForm, self).__init__(*args, **kwargs)
-
-        # Initialize rack choices if site is set
-        if self.initial.get('site'):
-            self.fields['rack'].queryset = Rack.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['rack'].choices = []
-
-        # Initialize device choices if rack or site is set
-        if self.initial.get('rack'):
-            self.fields['device'].queryset = Device.objects.filter(rack=self.initial['rack'])
-        elif self.initial.get('site'):
-            self.fields['device'].queryset = Device.objects.filter(site=self.initial['site'], rack__isnull=True)
-        else:
-            self.fields['device'].choices = []
-
-        # Initialize port choices if device is set
-        if self.initial.get('device'):
-            self.fields['port'].queryset = PowerPort.objects.filter(device=self.initial['device'])
-        else:
-            self.fields['port'].choices = []
-
 
 #
 # Interfaces
@@ -1468,7 +1380,7 @@ class InterfaceBulkEditForm(BootstrapMixin, BulkEditForm):
 # Interface connections
 #
 
-class InterfaceConnectionForm(BootstrapMixin, forms.ModelForm):
+class InterfaceConnectionForm(BootstrapMixin, ChainedFieldsMixin, forms.ModelForm):
     interface_a = forms.ChoiceField(
         choices=[],
         widget=SelectWithDisabled,
@@ -1482,8 +1394,9 @@ class InterfaceConnectionForm(BootstrapMixin, forms.ModelForm):
             attrs={'filter-for': 'rack_b'}
         )
     )
-    rack_b = forms.ModelChoiceField(
+    rack_b = ChainedModelChoiceField(
         queryset=Rack.objects.all(),
+        chains = {'site': 'site_b'},
         label='Rack',
         required=False,
         widget=APISelect(
@@ -1491,8 +1404,9 @@ class InterfaceConnectionForm(BootstrapMixin, forms.ModelForm):
             attrs={'filter-for': 'device_b', 'nullable': 'true'}
         )
     )
-    device_b = forms.ModelChoiceField(
+    device_b = ChainedModelChoiceField(
         queryset=Device.objects.all(),
+        chains = {'site': 'site_b', 'rack': 'rack_b'},
         label='Device',
         required=False,
         widget=APISelect(
@@ -1510,8 +1424,11 @@ class InterfaceConnectionForm(BootstrapMixin, forms.ModelForm):
             field_to_update='device_b'
         )
     )
-    interface_b = forms.ModelChoiceField(
-        queryset=Interface.objects.all(),
+    interface_b = ChainedModelChoiceField(
+        queryset=Interface.objects.exclude(form_factor__in=VIRTUAL_IFACE_TYPES).select_related(
+            'circuit_termination', 'connected_as_a', 'connected_as_b'
+        ),
+        chains = {'device': 'device_b'},
         label='Interface',
         widget=APISelect(
             api_url='/api/dcim/interfaces/?device_id={{device_b}}&type=physical',
@@ -1537,31 +1454,9 @@ class InterfaceConnectionForm(BootstrapMixin, forms.ModelForm):
             (iface.id, {'label': iface.name, 'disabled': iface.is_connected}) for iface in device_a_interfaces
         ]
 
-        # Initialize rack_b choices if site_b is set
-        if self.initial.get('site_b'):
-            self.fields['rack_b'].queryset = Rack.objects.filter(site=self.initial['site_b'])
-        else:
-            self.fields['rack_b'].choices = []
-
-        # Initialize device_b choices if rack_b or site_b is set
-        if self.initial.get('rack_b'):
-            self.fields['device_b'].queryset = Device.objects.filter(rack=self.initial['rack_b'])
-        elif self.initial.get('site_b'):
-            self.fields['device_b'].queryset = Device.objects.filter(site=self.initial['site_b'], rack__isnull=True)
-        else:
-            self.fields['device_b'].choices = []
-
-        # Initialize interface_b choices if device_b is set
-        if self.initial.get('device_b'):
-            device_b_interfaces = Interface.objects.filter(device=self.initial['device_b']).exclude(
-                form_factor__in=VIRTUAL_IFACE_TYPES
-            ).select_related(
-                'circuit_termination', 'connected_as_a', 'connected_as_b'
-            )
-        else:
-            device_b_interfaces = []
+        # Mark connected interfaces as disabled
         self.fields['interface_b'].choices = [
-            (iface.id, {'label': iface.name, 'disabled': iface.is_connected}) for iface in device_b_interfaces
+            (iface.id, {'label': iface.name, 'disabled': iface.is_connected}) for iface in self.fields['interface_b'].queryset
         ]
 
 

netbox/ipam/forms.py

@@ -5,8 +5,8 @@ from dcim.models import Site, Rack, Device, Interface
 from extras.forms import CustomFieldForm, CustomFieldBulkEditForm, CustomFieldFilterForm
 from tenancy.models import Tenant
 from utilities.forms import (
-    APISelect, BootstrapMixin, BulkEditNullBooleanSelect, BulkImportForm, CSVDataField, ExpandableIPAddressField,
-    FilterChoiceField, Livesearch, ReturnURLForm, SlugField, add_blank_choice,
+    APISelect, BootstrapMixin, BulkEditNullBooleanSelect, BulkImportForm, ChainedFieldsMixin, ChainedModelChoiceField,
+    CSVDataField, ExpandableIPAddressField, FilterChoiceField, Livesearch, ReturnURLForm, SlugField, add_blank_choice,
 )
 
 from .models import (
@@ -163,12 +163,17 @@ class RoleForm(BootstrapMixin, forms.ModelForm):
 # Prefixes
 #
 
-class PrefixForm(BootstrapMixin, CustomFieldForm):
-    site = forms.ModelChoiceField(queryset=Site.objects.all(), required=False, label='Site',
-                                  widget=forms.Select(attrs={'filter-for': 'vlan', 'nullable': 'true'}))
-    vlan = forms.ModelChoiceField(queryset=VLAN.objects.all(), required=False, label='VLAN',
-                                  widget=APISelect(api_url='/api/ipam/vlans/?site_id={{site}}',
-                                                   display_field='display_name'))
+class PrefixForm(BootstrapMixin, ChainedFieldsMixin, CustomFieldForm):
+    site = forms.ModelChoiceField(
+        queryset=Site.objects.all(), required=False, label='Site', widget=forms.Select(
+            attrs={'filter-for': 'vlan', 'nullable': 'true'}
+        )
+    )
+    vlan = ChainedModelChoiceField(
+        queryset=VLAN.objects.all(), chains={'site': 'site'}, required=False, label='VLAN', widget=APISelect(
+            api_url='/api/ipam/vlans/?site_id={{site}}', display_field='display_name'
+        )
+    )
 
     class Meta:
         model = Prefix
@@ -179,14 +184,6 @@ class PrefixForm(BootstrapMixin, CustomFieldForm):
 
         self.fields['vrf'].empty_label = 'Global'
 
-        # Initialize field without choices to avoid pulling all VLANs from the database
-        if self.is_bound and self.data.get('site'):
-            self.fields['vlan'].queryset = VLAN.objects.filter(site__pk=self.data['site'])
-        elif self.initial.get('site'):
-            self.fields['vlan'].queryset = VLAN.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['vlan'].queryset = VLAN.objects.filter(site=None)
-
 
 class PrefixFromCSVForm(forms.ModelForm):
     vrf = forms.ModelChoiceField(queryset=VRF.objects.all(), required=False, to_field_name='rd',
@@ -214,7 +211,6 @@ class PrefixFromCSVForm(forms.ModelForm):
         vlan_group_name = self.cleaned_data.get('vlan_group_name')
         vlan_vid = self.cleaned_data.get('vlan_vid')
         vlan_group = None
-        vlan = None
 
         # Validate VLAN group
         if vlan_group_name:
@@ -310,38 +306,93 @@ class PrefixFilterForm(BootstrapMixin, CustomFieldFilterForm):
 # IP addresses
 #
 
-class IPAddressForm(BootstrapMixin, ReturnURLForm, CustomFieldForm):
+class IPAddressForm(BootstrapMixin, ChainedFieldsMixin, ReturnURLForm, CustomFieldForm):
     interface_site = forms.ModelChoiceField(
-        queryset=Site.objects.all(), required=False, label='Site', widget=forms.Select(
+        queryset=Site.objects.all(),
+        required=False,
+        label='Site',
+        widget=forms.Select(
             attrs={'filter-for': 'interface_rack'}
         )
     )
-    interface_rack = forms.ModelChoiceField(
-        queryset=Rack.objects.all(), required=False, label='Rack', widget=APISelect(
-            api_url='/api/dcim/racks/?site_id={{interface_site}}', display_field='display_name',
+    interface_rack = ChainedModelChoiceField(
+        queryset=Rack.objects.all(),
+        chains={'site': 'interface_site'},
+        required=False,
+        label='Rack',
+        widget=APISelect(
+            api_url='/api/dcim/racks/?site_id={{interface_site}}',
+            display_field='display_name',
             attrs={'filter-for': 'interface_device', 'nullable': 'true'}
         )
     )
-    interface_device = forms.ModelChoiceField(
-        queryset=Device.objects.all(), required=False, label='Device', widget=APISelect(
+    interface_device = ChainedModelChoiceField(
+        queryset=Device.objects.all(),
+        chains={'site': 'interface_site', 'rack': 'interface_rack'},
+        required=False,
+        label='Device',
+        widget=APISelect(
             api_url='/api/dcim/devices/?site_id={{interface_site}}&rack_id={{interface_rack}}',
-            display_field='display_name', attrs={'filter-for': 'interface'}
+            display_field='display_name',
+            attrs={'filter-for': 'interface'}
+        )
+    )
+    interface = ChainedModelChoiceField(
+        queryset=Interface.objects.all(),
+        chains={'device': 'interface_device'},
+        required=False,
+        widget=APISelect(
+            api_url='/api/dcim/interfaces/?device_id={{interface_device}}'
         )
     )
     nat_site = forms.ModelChoiceField(
-        queryset=Site.objects.all(), required=False, label='Site', widget=forms.Select(
+        queryset=Site.objects.all(),
+        required=False,
+        label='Site',
+        widget=forms.Select(
             attrs={'filter-for': 'nat_device'}
         )
     )
-    nat_device = forms.ModelChoiceField(
-        queryset=Device.objects.all(), required=False, label='Device', widget=APISelect(
-            api_url='/api/dcim/devices/?site_id={{nat_site}}', display_field='display_name',
+    nat_rack = ChainedModelChoiceField(
+        queryset=Rack.objects.all(),
+        chains={'site': 'nat_site'},
+        required=False,
+        label='Rack',
+        widget=APISelect(
+            api_url='/api/dcim/racks/?site_id={{interface_site}}',
+            display_field='display_name',
+            attrs={'filter-for': 'nat_device', 'nullable': 'true'}
+        )
+    )
+    nat_device = ChainedModelChoiceField(
+        queryset=Device.objects.all(),
+        chains={'site': 'nat_site'},
+        required=False,
+        label='Device',
+        widget=APISelect(
+            api_url='/api/dcim/devices/?site_id={{nat_site}}',
+            display_field='display_name',
             attrs={'filter-for': 'nat_inside'}
         )
     )
+    nat_inside = ChainedModelChoiceField(
+        queryset=IPAddress.objects.all(),
+        chains={'interface__device': 'nat_device'},
+        required=False,
+        label='IP Address',
+        widget=APISelect(
+            api_url='/api/ipam/ip-addresses/?device_id={{nat_device}}',
+            display_field='address'
+        )
+    )
     livesearch = forms.CharField(
-        required=False, label='IP Address', widget=Livesearch(
-            query_key='q', query_url='ipam-api:ipaddress-list', field_to_update='nat_inside', obj_label='address'
+        required=False,
+        label='IP Address',
+        widget=Livesearch(
+            query_key='q',
+            query_url='ipam-api:ipaddress-list',
+            field_to_update='nat_inside',
+            obj_label='address'
         )
     )
     primary_for_device = forms.BooleanField(required=False, label='Make this the primary IP for the device')
@@ -349,45 +400,24 @@ class IPAddressForm(BootstrapMixin, ReturnURLForm, CustomFieldForm):
     class Meta:
         model = IPAddress
         fields = ['address', 'vrf', 'tenant', 'status', 'description', 'interface', 'primary_for_device', 'nat_inside']
-        widgets = {
-            'interface': APISelect(api_url='/api/dcim/interfaces/?device_id={{interface_device}}'),
-            'nat_inside': APISelect(api_url='/api/ipam/ip-addresses/?device_id={{nat_device}}', display_field='address')
-        }
 
-    def __init__(self, *args, **kwargs):
-        super(IPAddressForm, self).__init__(*args, **kwargs)
+    def __init__(self, instance=None, initial=None, *args, **kwargs):
 
-        self.fields['vrf'].empty_label = 'Global'
+        # Initialize interface selectors
+        if instance and instance.interface is not None:
+            initial['interface_site'] = instance.interface.device.site
+            initial['interface_rack'] = instance.interface.device.rack
+            initial['interface_device'] = instance.interface.device
 
-        # If an interface has been assigned, initialize site, rack, and device
-        if self.instance.interface:
-            self.initial['interface_site'] = self.instance.interface.device.site
-            self.initial['interface_rack'] = self.instance.interface.device.rack
-            self.initial['interface_device'] = self.instance.interface.device
-
-        # Limit rack choices
-        if self.is_bound and self.data.get('interface_site'):
-            self.fields['interface_rack'].queryset = Rack.objects.filter(site__pk=self.data['interface_site'])
-        elif self.initial.get('interface_site'):
-            self.fields['interface_rack'].queryset = Rack.objects.filter(site=self.initial['interface_site'])
-        else:
-            self.fields['interface_rack'].choices = []
+        # Initialize NAT selectors
+        if instance and instance.nat_inside is not None:
+            initial['nat_site'] = instance.nat_inside.device.site
+            initial['nat_rack'] = instance.nat_inside.device.rack
+            initial['nat_device'] = instance.nat_inside.device
 
-        # Limit device choices
-        if self.is_bound and self.data.get('interface_rack'):
-            self.fields['interface_device'].queryset = Device.objects.filter(rack=self.data['interface_rack'])
-        elif self.initial.get('interface_rack'):
-            self.fields['interface_device'].queryset = Device.objects.filter(rack=self.initial['interface_rack'])
-        else:
-            self.fields['interface_device'].choices = []
+        super(IPAddressForm, self).__init__(instance=instance, initial=initial, *args, **kwargs)
 
-        # Limit interface choices
-        if self.is_bound and self.data.get('interface_device'):
-            self.fields['interface'].queryset = Interface.objects.filter(device=self.data['interface_device'])
-        elif self.initial.get('interface_device'):
-            self.fields['interface'].queryset = Interface.objects.filter(device=self.initial['interface_device'])
-        else:
-            self.fields['interface'].choices = []
+        self.fields['vrf'].empty_label = 'Global'
 
         # Initialize primary_for_device if IP address is already assigned
         if self.instance.interface is not None:
@@ -398,38 +428,6 @@ class IPAddressForm(BootstrapMixin, ReturnURLForm, CustomFieldForm):
             ):
                 self.initial['primary_for_device'] = True
 
-        if self.instance.nat_inside:
-            nat_inside = self.instance.nat_inside
-            # If the IP is assigned to an interface, populate site/device fields accordingly
-            if self.instance.nat_inside.interface:
-                self.initial['nat_site'] = self.instance.nat_inside.interface.device.site.pk
-                self.initial['nat_device'] = self.instance.nat_inside.interface.device.pk
-                self.fields['nat_device'].queryset = Device.objects.filter(
-                    site=nat_inside.interface.device.site
-                )
-                self.fields['nat_inside'].queryset = IPAddress.objects.filter(
-                    interface__device=nat_inside.interface.device
-                )
-            else:
-                self.fields['nat_inside'].queryset = IPAddress.objects.filter(pk=nat_inside.pk)
-        else:
-            # Initialize nat_device choices if nat_site is set
-            if self.is_bound and self.data.get('nat_site'):
-                self.fields['nat_device'].queryset = Device.objects.filter(site__pk=self.data['nat_site'])
-            elif self.initial.get('nat_site'):
-                self.fields['nat_device'].queryset = Device.objects.filter(site=self.initial['nat_site'])
-            else:
-                self.fields['nat_device'].choices = []
-            # Initialize nat_inside choices if nat_device is set
-            if self.is_bound and self.data.get('nat_device'):
-                self.fields['nat_inside'].queryset = IPAddress.objects.filter(
-                    interface__device__pk=self.data['nat_device'])
-            elif self.initial.get('nat_device'):
-                self.fields['nat_inside'].queryset = IPAddress.objects.filter(
-                    interface__device__pk=self.initial['nat_device'])
-            else:
-                self.fields['nat_inside'].choices = []
-
     def clean(self):
         super(IPAddressForm, self).clean()
 
@@ -602,10 +600,22 @@ class VLANGroupFilterForm(BootstrapMixin, forms.Form):
 # VLANs
 #
 
-class VLANForm(BootstrapMixin, CustomFieldForm):
-    group = forms.ModelChoiceField(queryset=VLANGroup.objects.all(), required=False, label='Group', widget=APISelect(
-        api_url='/api/ipam/vlan-groups/?site_id={{site}}',
-    ))
+class VLANForm(BootstrapMixin, ChainedFieldsMixin, CustomFieldForm):
+    site = forms.ModelChoiceField(
+        queryset=Site.objects.all(),
+        widget=forms.Select(
+            attrs={'filter-for': 'group', 'nullable': 'true'}
+        )
+    )
+    group = ChainedModelChoiceField(
+        queryset=VLANGroup.objects.all(),
+        chains={'site': 'site'},
+        required=False,
+        label='Group',
+        widget=APISelect(
+            api_url='/api/ipam/vlan-groups/?site_id={{site}}',
+        )
+    )
 
     class Meta:
         model = VLAN
@@ -618,21 +628,6 @@ class VLANForm(BootstrapMixin, CustomFieldForm):
             'status': "Operational status of this VLAN",
             'role': "The primary function of this VLAN",
         }
-        widgets = {
-            'site': forms.Select(attrs={'filter-for': 'group', 'nullable': 'true'}),
-        }
-
-    def __init__(self, *args, **kwargs):
-
-        super(VLANForm, self).__init__(*args, **kwargs)
-
-        # Limit VLAN group choices
-        if self.is_bound and self.data.get('site'):
-            self.fields['group'].queryset = VLANGroup.objects.filter(site__pk=self.data['site'])
-        elif self.initial.get('site'):
-            self.fields['group'].queryset = VLANGroup.objects.filter(site=self.initial['site'])
-        else:
-            self.fields['group'].queryset = VLANGroup.objects.filter(site=None)
 
 
 class VLANFromCSVForm(forms.ModelForm):
@@ -663,7 +658,7 @@ class VLANFromCSVForm(forms.ModelForm):
         group_name = self.cleaned_data.get('group_name')
         if group_name:
             try:
-                vlan_group = VLANGroup.objects.get(site=self.cleaned_data.get('site'), name=group_name)
+                VLANGroup.objects.get(site=self.cleaned_data.get('site'), name=group_name)
             except VLANGroup.DoesNotExist:
                 self.add_error('group_name', "Invalid VLAN group {}.".format(group_name))
 

netbox/ipam/views.py

@@ -2,15 +2,12 @@ from django_tables2 import RequestConfig
 import netaddr
 
 from django.conf import settings
-from django.contrib.auth.decorators import permission_required
 from django.contrib.auth.mixins import PermissionRequiredMixin
-from django.contrib import messages
 from django.db.models import Count, Q
-from django.shortcuts import get_object_or_404, redirect, render
+from django.shortcuts import get_object_or_404, render
 from django.urls import reverse
 
 from dcim.models import Device
-from utilities.forms import ConfirmationForm
 from utilities.paginator import EnhancedPaginator
 from utilities.views import (
     BulkAddView, BulkDeleteView, BulkEditView, BulkImportView, ObjectDeleteView, ObjectEditView, ObjectListView,

netbox/utilities/forms.py

@@ -331,6 +331,25 @@ class FlexibleModelChoiceField(forms.ModelChoiceField):
         return value
 
 
+class ChainedModelChoiceField(forms.ModelChoiceField):
+    """
+    A ModelChoiceField which is initialized based on the values of other fields within a form. `chains` is a dictionary
+    mapping of model fields to peer fields within the form. For example:
+    
+        country1 = forms.ModelChoiceField(queryset=Country.objects.all())
+        city1 = ChainedModelChoiceField(queryset=City.objects.all(), chains={'country': 'country1'}
+    
+    The queryset of the `city1` field will be modified as
+    
+        .filter(country=<value>)
+    
+    where <value> is the value of the `country1` field. (Note: The form must inherit from ChainedFieldsMixin.)
+    """
+    def __init__(self, chains=None, *args, **kwargs):
+        self.chains = chains
+        super(ChainedModelChoiceField, self).__init__(*args, **kwargs)
+
+
 class SlugField(forms.SlugField):
 
     def __init__(self, slug_source='name', *args, **kwargs):
@@ -411,6 +430,32 @@ class BootstrapMixin(forms.BaseForm):
                 field.widget.attrs['placeholder'] = field.label
 
 
+class ChainedFieldsMixin(forms.BaseForm):
+    """
+    Iterate through all ChainedModelChoiceFields in the form and modify their querysets based on chained fields.
+    """
+    def __init__(self, *args, **kwargs):
+        super(ChainedFieldsMixin, self).__init__(*args, **kwargs)
+
+        for field_name, field in self.fields.items():
+
+            if isinstance(field, ChainedModelChoiceField):
+
+                filters_dict = {}
+                for db_field, parent_field in field.chains.items():
+                    if self.is_bound and self.data.get(parent_field):
+                        filters_dict[db_field] = self.data.get(parent_field)
+                    elif self.initial.get(parent_field):
+                        filters_dict[db_field] = self.initial[parent_field]
+                    else:
+                        filters_dict[db_field] = None
+
+                if filters_dict:
+                    field.queryset = field.queryset.filter(**filters_dict)
+                else:
+                    field.queryset = field.queryset.none()
+
+
 class ReturnURLForm(forms.Form):
     """
     Provides a hidden return URL field to control where the user is directed after the form is submitted.