Merge pull request #289 from SchrodingersGat/delete_on_empty

Delete on empty

InvenTree/stock/forms.py

@@ -34,6 +34,7 @@ class CreateStockItemForm(HelperForm):
             'location',
             'batch',
             'quantity',
+            'delete_on_deplete',
             'status',
             'notes',
             'URL',
@@ -78,6 +79,7 @@ class EditStockItemForm(HelperForm):
         fields = [
             'supplier_part',
             'batch',
+            'delete_on_deplete',
             'status',
             'notes',
             'URL',

InvenTree/stock/migrations/0015_stockitem_delete_on_deplete.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2 on 2019-05-09 12:59
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('stock', '0014_auto_20190508_2332'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='stockitem',
+            name='delete_on_deplete',
+            field=models.BooleanField(default=True, help_text='Delete this Stock Item when stock is depleted'),
+        ),
+    ]

InvenTree/stock/models.py

@@ -93,7 +93,7 @@ class StockItem(models.Model):
 
         if add_note:
             # This StockItem is being saved for the first time
-            self.add_transaction_note(
+            self.addTransactionNote(
                 'Created stock item',
                 None,
                 notes="Created new stock item for part '{p}'".format(p=str(self.part)),
@@ -221,6 +221,8 @@ class StockItem(models.Model):
 
     review_needed = models.BooleanField(default=False)
 
+    delete_on_deplete = models.BooleanField(default=True, help_text='Delete this Stock Item when stock is depleted')
+
     ITEM_OK = 10
     ITEM_ATTENTION = 50
     ITEM_DAMAGED = 55
@@ -261,7 +263,11 @@ class StockItem(models.Model):
     def has_tracking_info(self):
         return self.tracking_info.count() > 0
 
-    def add_transaction_note(self, title, user, notes='', system=True):
+    def addTransactionNote(self, title, user, notes='', system=True):
+        """ Generation a stock transaction note for this item.
+
+        Brief automated note detailing a movement or quantity change.
+        """
         track = StockItemTracking.objects.create(
             item=self,
             title=title,
@@ -290,13 +296,37 @@ class StockItem(models.Model):
             msg += " (from {loc})".format(loc=str(self.location))
 
         self.location = location
-        self.save()
 
-        self.add_transaction_note(msg,
+        self.addTransactionNote(msg,
                                 user,
                                 notes=notes,
                                 system=True)
 
+        self.save()
+
+        return True
+
+    @transaction.atomic
+    def updateQuantity(self, quantity):
+        """ Update stock quantity for this item.
+        
+        If the quantity has reached zero, this StockItem will be deleted.
+
+        Returns:
+            - True if the quantity was saved
+            - False if the StockItem was deleted
+        """
+
+        if quantity < 0:
+            quantity = 0
+
+        self.quantity = quantity
+
+        if quantity <= 0 and self.delete_on_deplete:
+            self.delete()
+            return False
+        else:
+            self.save()
             return True
 
     @transaction.atomic
@@ -311,12 +341,12 @@ class StockItem(models.Model):
         if count < 0 or self.infinite:
             return False
 
-        self.quantity = count
         self.stocktake_date = datetime.now().date()
         self.stocktake_user = user
-        self.save()
 
-        self.add_transaction_note('Stocktake - counted {n} items'.format(n=count),
+        if self.updateQuantity(count):
+
+            self.addTransactionNote('Stocktake - counted {n} items'.format(n=count),
                                     user,
                                     notes=notes,
                                     system=True)
@@ -336,11 +366,9 @@ class StockItem(models.Model):
         if quantity <= 0 or self.infinite:
             return False
 
-        self.quantity += quantity
+        if self.updateQuantity(self.quantity + quantity):
             
-        self.save()
+            self.addTransactionNote('Added {n} items to stock'.format(n=quantity),
-
-        self.add_transaction_note('Added {n} items to stock'.format(n=quantity),
                                     user,
                                     notes=notes,
                                     system=True)
@@ -360,14 +388,9 @@ class StockItem(models.Model):
         if quantity <= 0 or self.infinite:
             return False
 
-        self.quantity -= quantity
+        if self.updateQuantity(self.quantity - quantity):
 
-        if self.quantity < 0:
+            self.addTransactionNote('Removed {n} items from stock'.format(n=quantity),
-            self.quantity = 0
-
-        self.save()
-
-        self.add_transaction_note('Removed {n} items from stock'.format(n=quantity),
                                     user,
                                     notes=notes,
                                     system=True)