From 317c2666b83c18458aa664648b98d8a5018d9631 Mon Sep 17 00:00:00 2001
From: Oliver <oliver.henry.walters@gmail.com>
Date: Tue, 21 Nov 2023 00:12:25 +1100
Subject: [PATCH] Improvements for part.full_name (#5946)

* Improvements for part.full_name

- Compile and cache the template
- Reduces typical render time from ~20ms to ~0.2ms

* Force autoescape
---
 InvenTree/part/helpers.py | 68 +++++++++++++++++++++++++++++++++++++++
 InvenTree/part/models.py  | 38 ++--------------------
 2 files changed, 71 insertions(+), 35 deletions(-)
 create mode 100644 InvenTree/part/helpers.py

diff --git a/InvenTree/part/helpers.py b/InvenTree/part/helpers.py
new file mode 100644
index 0000000000..08ee86d3b5
--- /dev/null
+++ b/InvenTree/part/helpers.py
@@ -0,0 +1,68 @@
+"""Various helper functions for the part app"""
+
+import logging
+
+from jinja2 import Environment
+
+logger = logging.getLogger('inventree')
+
+
+# Compiled template for rendering the 'full_name' attribute of a Part
+_part_full_name_template = None
+_part_full_name_template_string = ''
+
+
+def compile_full_name_template(*args, **kwargs):
+    """Recompile the template for rendering the 'full_name' attribute of a Part.
+
+    This function is called whenever the 'PART_NAME_FORMAT' setting is changed.
+    """
+
+    from common.models import InvenTreeSetting
+
+    global _part_full_name_template
+    global _part_full_name_template_string
+
+    template_string = InvenTreeSetting.get_setting('PART_NAME_FORMAT', '')
+
+    # Skip if the template string has not changed
+    if template_string == _part_full_name_template_string and _part_full_name_template is not None:
+        return _part_full_name_template
+
+    _part_full_name_template_string = template_string
+
+    env = Environment(
+        autoescape=True,
+        variable_start_string='{{',
+        variable_end_string='}}'
+    )
+
+    # Compile the template
+    try:
+        _part_full_name_template = env.from_string(template_string)
+    except Exception:
+        _part_full_name_template = None
+
+    return _part_full_name_template
+
+
+def render_part_full_name(part) -> str:
+    """Render the 'full_name' attribute of a Part.
+
+    To improve render efficiency, we re-compile the template whenever the setting is changed
+
+    Args:
+        part: The Part object to render
+    """
+
+    template = compile_full_name_template()
+
+    if template:
+        try:
+            return template.render(part=part)
+        except Exception as e:
+            logger.warning("exception while trying to create full name for part %s: %s", part.name, e)
+
+    # Fallback to the default format
+    elements = [el for el in [part.IPN, part.name, part.revision] if el]
+    return ' | '.join(elements)
diff --git a/InvenTree/part/models.py b/InvenTree/part/models.py
index 745704f580..4af2fc1b61 100644
--- a/InvenTree/part/models.py
+++ b/InvenTree/part/models.py
@@ -27,7 +27,6 @@ from django_cleanup import cleanup
 from djmoney.contrib.exchange.exceptions import MissingRate
 from djmoney.contrib.exchange.models import convert_money
 from djmoney.money import Money
-from jinja2 import Template
 from mptt.exceptions import InvalidMove
 from mptt.managers import TreeManager
 from mptt.models import MPTTModel, TreeForeignKey
@@ -40,6 +39,7 @@ import InvenTree.conversion
 import InvenTree.fields
 import InvenTree.ready
 import InvenTree.tasks
+import part.helpers as part_helpers
 import part.settings as part_settings
 import users.models
 from build import models as BuildModels
@@ -692,41 +692,9 @@ class Part(InvenTreeBarcodeMixin, InvenTreeNotesMixin, MetadataMixin, MPTTModel)
 
     @property
     def full_name(self):
-        """Format a 'full name' for this Part based on the format PART_NAME_FORMAT defined in InvenTree settings.
+        """Format a 'full name' for this Part based on the format PART_NAME_FORMAT defined in InvenTree settings"""
 
-        As a failsafe option, the following is done:
-
-        - IPN (if not null)
-        - Part name
-        - Part variant (if not null)
-
-        Elements are joined by the | character
-        """
-        full_name_pattern = InvenTreeSetting.get_setting('PART_NAME_FORMAT')
-
-        try:
-            context = {'part': self}
-            template_string = Template(full_name_pattern)
-            full_name = template_string.render(context)
-
-            return full_name
-
-        except Exception as attr_err:
-
-            logger.warning("exception while trying to create full name for part %s: %s", self.name, attr_err)
-
-            # Fallback to default format
-            elements = []
-
-            if self.IPN:
-                elements.append(self.IPN)
-
-            elements.append(self.name)
-
-            if self.revision:
-                elements.append(self.revision)
-
-            return ' | '.join(elements)
+        return part_helpers.render_part_full_name(self)
 
     def get_absolute_url(self):
         """Return the web URL for viewing this part."""