Created part.tasks file and moved notify_low_stock function to the same from InvenTree.tasks. The argument type is changed from StockItem to Part

Added trans to headers of table in email template of low_stock_notification.html

added is_part_low_on_stock() function to the part model to check if the part's stock has fallen below the minimum quantity

used offload_task function to run the low stock notification function asynchronously

InvenTree/part/models.py

@@ -1988,6 +1988,9 @@ class Part(MPTTModel):
     def related_count(self):
         return len(self.get_related_parts())
 
+    def is_part_low_on_stock(self):
+        return self.total_stock <= self.minimum_stock
+
 
 def attach_file(instance, filename):
     """ Function for storing a file for a PartAttachment

InvenTree/part/tasks.py

@@ -0,0 +1,39 @@
+# Author: Roche Christopher
+# Created at 10:26 AM on 31/10/21
+
+import logging
+
+from django.utils.translation import ugettext_lazy as _
+from django.template.loader import render_to_string
+
+from InvenTree import tasks as inventree_tasks
+from part.models import Part
+
+logger = logging.getLogger("inventree")
+
+
+def notify_low_stock(part: Part):
+    """
+    Notify users who have starred a part when its stock quantity falls below the minimum threshold
+    """
+
+    from allauth.account.models import EmailAddress
+    starred_users_email = EmailAddress.objects.filter(user__starred_parts__part=part)
+
+    if len(starred_users_email) > 0:
+        logger.info(f"Notify users regarding low stock of {part.name}")
+        context = {
+            'part_name': part.name,
+            # Part url can be used to open the page of part in application from the email.
+            # It can be facilitated when the application base url is accessible programmatically.
+            # 'part_url': f'{application_base_url}/part/{stock_item.part.id}',
+
+            # quantity is in decimal field datatype. Since the same datatype is used in models,
+            # it is not converted to number/integer,
+            'part_quantity': part.total_stock,
+            'minimum_quantity': part.minimum_stock
+        }
+        subject = _(f'Attention! {part.name} is low on stock')
+        html_message = render_to_string('stock/low_stock_notification.html', context)
+        recipients = starred_users_email.values_list('email', flat=True)
+        inventree_tasks.send_email(subject, '', recipients, html_message=html_message)