add list of lists

this lists show all the lists related to the currently selected customer.

network_inventory/inventory/templates/inventory/list_of_lists.html

@@ -0,0 +1,15 @@
+{% extends "inventory/base.html" %}
+{% block section_title %}List of Lists{% endblock %}
+{% block content %}
+<table class="sortable">
+    <tr>
+        <th>Lists</th>
+    </tr>
+    <tr>
+        <td><a href="{% url 'computers' customer_id %}">Computers</a></td>
+    </tr>
+    <tr>
+        <td><a href="{% url 'devices' customer_id %}">Devices</a></td>
+    </tr>
+</table>
+{% endblock %}

network_inventory/inventory/urls.py

@@ -9,7 +9,8 @@ urlpatterns = [
     path('device/<int:device_id>/', views.device_details, name='device'),
     path('computer/<int:computer_id>/', views.computer_details,
          name='computer'),
-    path('devices/', views.DeviceList.as_view(), name='devices'),
+    path('devices/<int:customer_id>', views.DeviceList.as_view(),
+         name='devices'),
     path('customer/<int:customer_id>/lists/', views.list_of_lists,
          name='lists'),
  ]

network_inventory/inventory/views.py

@@ -29,7 +29,8 @@ def computer_details(request, computer_id):
 
 
 def list_of_lists(request, customer_id):
-    return render(request, 'inventory/list_of_lists.html')
+    return render(request, 'inventory/list_of_lists.html',
+                  {'customer_id': customer_id})
 
 
 class CustomerList(ListView):
@@ -56,3 +57,8 @@ class DeviceList(ListView):
     model = Device
     context_object_name = 'device_list'
     template_name = 'inventory/device_list.html'
+
+    def get_queryset(self):
+        queryset = Device.objects.filter(customer=self.kwargs['customer_id'])
+        return queryset
+