Improved serializer for transaction and added available equipment viewset

equipment_tracker/equipments/admin.py

@@ -6,11 +6,11 @@ from .models import Equipment, EquipmentInstance
 @admin.register(Equipment)
 class EquipmentAdmin(SimpleHistoryAdmin):
     readonly_fields = ('date_added', 'last_updated')
-    list_display = ('name', 'date_added', 'last_updated')
+    list_display = ('id', 'name', 'date_added', 'last_updated')
 
 
 @admin.register(EquipmentInstance)
 class EquipmentInstanceAdmin(SimpleHistoryAdmin):
     readonly_fields = ('date_added', 'last_updated')
-    list_display = ('equipment', 'status', 'remarks',
+    list_display = ('id', 'equipment', 'status', 'remarks',
                     'date_added', 'last_updated')

equipment_tracker/equipments/models.py

@@ -19,12 +19,13 @@ class Equipment(models.Model):
     history = HistoricalRecords()
 
     def __str__(self):
-        return f'{self.name} ID:{self.id}'
+        return f'{self.name}'
 
 
 class EquipmentInstance(models.Model):
     EQUIPMENT_INSTANCE_STATUS_CHOICES = (
         ('Available', 'Available'),
+        ('Pending', 'Pending'),
         ('Broken', 'Broken'),
         ('Borrowed', 'Borrowed'),
     )
@@ -37,7 +38,7 @@ class EquipmentInstance(models.Model):
     history = HistoricalRecords()
 
     def __str__(self):
-        return f'{self.equipment.name} ID:{self.id}'
+        return f'{self.equipment.name}'
 
 
 @receiver(post_migrate)
@@ -48,19 +49,25 @@ def create_superuser(sender, **kwargs):
                 'name': 'Pyrex Beaker',
                 'description': '',
                 'category': 'Glassware',
-                'remarks': 'First beaker of equipment tracker!'
+                'remarks': 'A beaker for storing fluids'
             },
             {
                 'name': 'Bunsen Burner',
                 'description': '',
                 'category': 'Miscellaneous',
-                'remarks': 'First bunsen burner of equipment tracker!'
+                'remarks': 'A burner for heating things'
             },
             {
                 'name': 'Microscope',
                 'description': '',
                 'category': 'Miscellaneous',
-                'remarks': 'First microscope of equipment tracker!'
+                'remarks': 'A microscope for zooming into tiny objects'
+            },
+            {
+                'name': 'Petri Dish',
+                'description': '',
+                'category': 'Glassware',
+                'remarks': 'A petri dish'
             }
         ]
 
@@ -72,6 +79,8 @@ def create_superuser(sender, **kwargs):
             )
             if (CREATED):
                 print('Created Equipment: ' + data['name'])
+                print(
+                    'Generating 3 Equipment Instances for Equipment: ' + data['name'])
                 # Generate 3 equipment instances per SKU
                 for x in range(3):
                     EQUIPMENT_INSTANCE = EquipmentInstance.objects.create(

equipment_tracker/equipments/urls.py

@@ -18,6 +18,10 @@ urlpatterns = [
          views.EquipmentLogViewSet.as_view({'get': 'list'})),
     # Last changed equipment
     path('equipments/latest', views.LastUpdatedEquipmentViewSet.as_view()),
+    # List of equipment instances that are available for borrowing (those not belonging to a non-finalized transaction)
+    path('equipment_instances/available',
+         views.AvailableEquipmentInstanceViewSet.as_view()),
+    # Logs for each equipment instance
     # Logs for all equipment instances
     path('equipment_instances/logs', views.EquipmentInstancesLogsViewSet.as_view()),
     # Logs for each equipment instance

equipment_tracker/equipments/views.py

@@ -1,9 +1,11 @@
 from rest_framework.permissions import IsAuthenticated
 from rest_framework import viewsets, generics
 from .models import Equipment, EquipmentInstance
+from django.db.models import Q
 from . import serializers
 from config.settings import DEBUG
 from accounts.permissions import IsTechnician
+from transactions.models import Transaction
 
 # -- Equipment Viewsets
 
@@ -56,6 +58,31 @@ class EquipmentInstanceViewSet(viewsets.ModelViewSet):
     serializer_class = serializers.EquipmentInstanceSerializer
     queryset = EquipmentInstance.objects.all().order_by('id')
 
+
+class AvailableEquipmentInstanceViewSet(generics.ListAPIView):
+    if (not DEBUG):
+        permission_classes = [IsAuthenticated]
+    serializer_class = serializers.EquipmentInstanceSerializer
+
+    def get_queryset(self):
+        """
+        This view should return a list of all the equipment instances
+        that are not associated with a non-finalized transaction.
+        """
+        # Get all non-finalized transactions
+        non_finalized_transactions = Transaction.objects.filter(
+            ~Q(transaction_status__in=['Finalized', 'Cancelled']))
+
+        # Get all equipment instances associated with non-finalized transactions
+        non_finalized_equipments = EquipmentInstance.objects.filter(
+            transaction__in=non_finalized_transactions)
+
+        # Get all equipment instances which are not associated with non-finalized transactions
+        queryset = EquipmentInstance.objects.exclude(
+            id__in=non_finalized_equipments.values_list('id', flat=True)).order_by('id')
+
+        return queryset
+
 # For viewing all equipment instance logs