Create Signal to handle items transfer / finish up overview

inventory/admin.py

@@ -7,8 +7,8 @@ class WarehouseAdmin(admin.ModelAdmin):
 
 @admin.register(Inventory)
 class InventoryAdmin(admin.ModelAdmin):
-    list_display = ('warehouse', 'max_stock', 'min_stock', 'current_stock')
+    list_display = ('stock_identifier', 'warehouse', 'max_stock', 'min_stock', 'current_stock')
 
 @admin.register(Item)
 class ItemAdmin(admin.ModelAdmin):
-    list_display = ('inventory', 'name', 'description', 'category', 'weight', 'quantity')
+    list_display = ('name', 'description', 'category', 'weight', 'quantity', 'inventory')

inventory/apps.py

@@ -4,3 +4,6 @@ from django.apps import AppConfig
 class InventoryConfig(AppConfig):
     default_auto_field = 'django.db.models.BigAutoField'
     name = 'inventory'
+
+    def ready(self):
+        import inventory.signals

inventory/models.py

@@ -37,13 +37,17 @@ class Inventory(models.Model):
     """
     warehouse = models.ForeignKey(Warehouse, on_delete=models.CASCADE)
     max_stock = models.IntegerField()
-    min_stock = models.IntegerField()
-    current_stock = models.IntegerField()
+    min_stock = models.IntegerField(default=0)
+    current_stock = models.IntegerField(default=0)
 
     @property
     def stock_percentage(self) -> float:
         return self.current_stock / self.max_stock * 100
 
+    @property
+    def stock_identifier(self) -> str:
+        return f"#{self.id} {self.warehouse.name}"
+
     def __str__(self):
         return f"{self.warehouse.name} - {self.stock_percentage}%"
 

inventory/signals.py

@@ -0,0 +1,41 @@
+from django.db.models.signals import post_save, pre_save
+from django.dispatch import receiver
+from inventory.models import Item
+from transaction.models import Transfer
+
+
+@receiver(pre_save, sender=Item)
+def handle_item_move(sender, instance, **kwargs):
+    """
+    Signal to handle moving an Item to a new Inventory.
+    """
+    if instance.pk:
+        old_item = Item.objects.get(pk=instance.pk)
+        if old_item.inventory != instance.inventory:
+            old_item.inventory.current_stock -= old_item.quantity
+            old_item.inventory.save()
+
+@receiver(post_save, sender=Item)
+def update_inventory_current_stock(sender, instance, **kwargs):
+    """
+    Signal to update current_stock of related Inventory when an Item is created or assigned to a new Inventory.
+    """
+    if kwargs.get('created', False) or instance.pk:
+        instance.inventory.current_stock += instance.quantity
+        instance.inventory.save()
+
+
+@receiver(post_save, sender=Item)
+def create_transfer_instance(sender, instance, **kwargs):
+    """
+    Signal to create a Transfer instance when an Item is transferred between warehouses.
+    """
+    # If the item is being created or updated
+    if kwargs.get('created', False) or instance.pk:
+        if instance.pk and instance.inventory.warehouse != instance.inventory.old_warehouse:
+            Transfer.objects.create(
+                from_warehouse=instance.inventory.old_warehouse,
+                to_warehouse=instance.inventory.warehouse,
+                item=instance,
+                quantity=instance.quantity,
+            )

templates/inventory/overview.html

@@ -229,7 +229,7 @@
                                             </div>
                                             <div class="row no-gutters align-items-center">
                                                 <div class="col-auto">
-                                                    <div class="h5 mb-0 mr-3 font-weight-bold text-gray-800">{{ stock_percentage }}%</div>
+                                                    <div class="h5 mb-0 mr-3 font-weight-bold text-gray-800">{{ stock_percentage|floatformat:3 }}%</div>
                                                 </div>
                                                 <div class="col">
                                                     <div class="progress progress-sm mr-2">
@@ -280,11 +280,11 @@
                                 <div class="card-body">
                                     {% if warehouse_list|length != 0 %}
                                         {% for warehouse in warehouse_list %}
-                                        <h4 class="small font-weight-bold">Account Setup <span class="float-right">
-                                            {% if warehouse.stock_percentage == 100 %}Complete!{% else %}{{ warehouse.stock_percentage }}%{% endif %}
+                                        <h4 class="small font-weight-bold my-2">{{ warehouse.name }} <span class="float-right">
+                                            {% if warehouse.stock_percentage == 100 %}Complete!{% else %}{{ warehouse.stock_percentage|floatformat:3 }}%{% endif %}
                                         </span></h4>
                                         <div class="progress">
-                                            <div class="progress-bar bg-success" role="progressbar" style="width: 100%" aria-valuenow="100" aria-valuemin="0" aria-valuemax="100"></div>
+                                            <div class="progress-bar bg-success" role="progressbar" style="width: {{ warehouse.stock_percentage }}%" aria-valuenow="100" aria-valuemin="0" aria-valuemax="100"></div>
                                         </div>
                                         {% endfor %}
                                         {% else %}