From 9884fe5c5e733effe39292429ef4f0fa3fb9b8aa Mon Sep 17 00:00:00 2001
From: Oliver Walters <oliver.henry.walters@gmail.com>
Date: Thu, 14 Jan 2021 08:15:05 +1100
Subject: [PATCH] Improve validators for 'filters' field

---
 InvenTree/InvenTree/helpers.py                | 13 ++++++-
 .../migrations/0005_auto_20210113_2302.py     | 24 ++++++++++++
 InvenTree/label/models.py                     | 37 +++++++++++++++----
 3 files changed, 65 insertions(+), 9 deletions(-)
 create mode 100644 InvenTree/label/migrations/0005_auto_20210113_2302.py

diff --git a/InvenTree/InvenTree/helpers.py b/InvenTree/InvenTree/helpers.py
index 37a8bf82e1..e65e67951e 100644
--- a/InvenTree/InvenTree/helpers.py
+++ b/InvenTree/InvenTree/helpers.py
@@ -12,7 +12,7 @@ from decimal import Decimal
 
 from wsgiref.util import FileWrapper
 from django.http import StreamingHttpResponse
-from django.core.exceptions import ValidationError
+from django.core.exceptions import ValidationError, FieldError
 from django.utils.translation import ugettext as _
 
 from django.contrib.auth.models import Permission
@@ -414,7 +414,7 @@ def extract_serial_numbers(serials, expected_quantity):
     return numbers
 
 
-def validateFilterString(value):
+def validateFilterString(value, model=None):
     """
     Validate that a provided filter string looks like a list of comma-separated key=value pairs
 
@@ -464,6 +464,15 @@ def validateFilterString(value):
 
         results[k] = v
 
+    # If a model is provided, verify that the provided filters can be used against it
+    if model is not None:
+        try:
+            query = model.objects.filter(**results)
+        except FieldError as e:
+            raise ValidationError(
+                str(e),
+            )
+
     return results
 
 
diff --git a/InvenTree/label/migrations/0005_auto_20210113_2302.py b/InvenTree/label/migrations/0005_auto_20210113_2302.py
new file mode 100644
index 0000000000..ad256412ac
--- /dev/null
+++ b/InvenTree/label/migrations/0005_auto_20210113_2302.py
@@ -0,0 +1,24 @@
+# Generated by Django 3.0.7 on 2021-01-13 12:02
+
+from django.db import migrations, models
+import label.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('label', '0004_auto_20210111_2302'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='stockitemlabel',
+            name='filters',
+            field=models.CharField(blank=True, help_text='Query filters (comma-separated list of key=value pairs', max_length=250, validators=[label.models.validate_stock_item_filters], verbose_name='Filters'),
+        ),
+        migrations.AlterField(
+            model_name='stocklocationlabel',
+            name='filters',
+            field=models.CharField(blank=True, help_text='Query filters (comma-separated list of key=value pairs', max_length=250, validators=[label.models.validate_stock_location_filters], verbose_name='Filters'),
+        ),
+    ]
diff --git a/InvenTree/label/models.py b/InvenTree/label/models.py
index 3e693b1e50..a34aa3831d 100644
--- a/InvenTree/label/models.py
+++ b/InvenTree/label/models.py
@@ -28,6 +28,20 @@ def rename_label(instance, filename):
     return os.path.join('label', 'template', instance.SUBDIR, filename)
 
 
+def validate_stock_item_filters(filters):
+    
+    filters = validateFilterString(filters, model=stock.models.StockItem)
+
+    return filters
+
+
+def validate_stock_location_filters(filters):
+
+    filters = validateFilterString(filters, model=stock.models.StockLocation)
+
+    return filters
+
+
 class LabelTemplate(models.Model):
     """
     Base class for generic, filterable labels.
@@ -71,13 +85,6 @@ class LabelTemplate(models.Model):
         validators=[FileExtensionValidator(allowed_extensions=['html'])],
     )
 
-    filters = models.CharField(
-        blank=True, max_length=250,
-        help_text=_('Query filters (comma-separated list of key=value pairs'),
-        verbose_name=_('Filters'),
-        validators=[validateFilterString]
-    )
-
     enabled = models.BooleanField(
         default=True,
         verbose_name=_('Enabled'),
@@ -125,6 +132,14 @@ class StockItemLabel(LabelTemplate):
 
     SUBDIR = "stockitem"
 
+    filters = models.CharField(
+        blank=True, max_length=250,
+        help_text=_('Query filters (comma-separated list of key=value pairs'),
+        verbose_name=_('Filters'),
+        validators=[
+            validate_stock_item_filters]
+    )
+
     def matches_stock_item(self, item):
         """
         Test if this label template matches a given StockItem object
@@ -170,6 +185,14 @@ class StockLocationLabel(LabelTemplate):
 
     SUBDIR = "stocklocation"
 
+    filters = models.CharField(
+        blank=True, max_length=250,
+        help_text=_('Query filters (comma-separated list of key=value pairs'),
+        verbose_name=_('Filters'),
+        validators=[
+            validate_stock_location_filters]
+    )
+
     def matches_stock_location(self, location):
         """
         Test if this label template matches a given StockLocation object