Restore total length count on trace view

docs/release-notes/version-2.10.md

@@ -71,7 +71,9 @@ All end-to-end cable paths are now cached using the new CablePath model. This al
 * dcim.ConsoleServerPort:
   * Replaced `connection_status` with `connected_endpoint_reachable` (boolean)
   * Added `cable_peer` and `cable_peer_type`
-* dcim.FrontPort: Added `cable_peer` and `cable_peer_type`
+* dcim.FrontPort:
+  * Removed the `/trace/` endpoint
+  * Added `cable_peer` and `cable_peer_type`
 * dcim.Interface:
   * Replaced `connection_status` with `connected_endpoint_reachable` (boolean)
   * Added `cable_peer` and `cable_peer_type`
@@ -85,7 +87,9 @@ All end-to-end cable paths are now cached using the new CablePath model. This al
   * Replaced `connection_status` with `connected_endpoint_reachable` (boolean)
   * Added `cable_peer` and `cable_peer_type`
 * dcim.RackReservation: Added `custom_fields`
-* dcim.RearPort: Added `cable_peer` and `cable_peer_type`
+* dcim.RearPort:
+  * Removed the `/trace/` endpoint
+  * Added `cable_peer` and `cable_peer_type`
 * dcim.VirtualChassis: Added `custom_fields`
 * extras.ExportTemplate: The `template_language` field has been removed
 * extras.Graph: This API endpoint has been removed (see #4349)

netbox/dcim/models/devices.py

@@ -7,7 +7,7 @@ from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ObjectDoesNotExist, ValidationError
 from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models
-from django.db.models import F, ProtectedError
+from django.db.models import F, ProtectedError, Sum
 from django.urls import reverse
 from django.utils.safestring import mark_safe
 from taggit.managers import TaggableManager
@@ -15,7 +15,7 @@ from taggit.managers import TaggableManager
 from dcim.choices import *
 from dcim.constants import *
 from dcim.fields import PathField
-from dcim.utils import path_node_to_object
+from dcim.utils import decompile_path_node, path_node_to_object
 from extras.models import ChangeLoggedModel, ConfigContextModel, CustomFieldModel, TaggedItem
 from extras.utils import extras_features
 from utilities.choices import ColorChoices
@@ -1228,6 +1228,16 @@ class CablePath(models.Model):
         model = self.origin._meta.model
         model.objects.filter(pk=self.origin.pk).update(_path=self.pk)
 
+    def get_total_length(self):
+        """
+        Return the sum of the length of each cable in the path.
+        """
+        cable_ids = [
+            # Starting from the first element, every third element in the path should be a Cable
+            decompile_path_node(self.path[i])[1] for i in range(0, len(self.path), 3)
+        ]
+        return Cable.objects.filter(id__in=cable_ids).aggregate(total=Sum('_abs_length'))['total']
+
 
 #
 # Virtual chassis

netbox/dcim/utils.py

@@ -4,20 +4,29 @@ from .choices import CableStatusChoices
 from .exceptions import CableTraceSplit
 
 
+def compile_path_node(ct_id, object_id):
+    return f'{ct_id}:{object_id}'
+
+
+def decompile_path_node(repr):
+    ct_id, object_id = repr.split(':')
+    return int(ct_id), int(object_id)
+
+
 def object_to_path_node(obj):
     """
     Return a representation of an object suitable for inclusion in a CablePath path. Node representation is in the
     form <ContentType ID>:<Object ID>.
     """
     ct = ContentType.objects.get_for_model(obj)
-    return f'{ct.pk}:{obj.pk}'
+    return compile_path_node(ct.pk, obj.pk)
 
 
 def path_node_to_object(repr):
     """
     Given a path node representation, return the corresponding object.
     """
-    ct_id, object_id = repr.split(':')
+    ct_id, object_id = decompile_path_node(repr)
     model_class = ContentType.objects.get(pk=ct_id).model_class()
     return model_class.objects.get(pk=int(object_id))
 

netbox/dcim/views.py

@@ -1984,15 +1984,11 @@ class PathTraceView(ObjectView):
             else:
                 path = related_paths.first()
 
-        # total_length = sum(
-        #     [entry[1]._abs_length for entry in path if entry[1] and entry[1]._abs_length]
-        # )
-
         return render(request, 'dcim/cable_trace.html', {
             'obj': obj,
             'path': path,
             'related_paths': related_paths,
-            # 'total_length': total_length,
+            'total_length': path.get_total_length(),
         })