✅ feat: add validation for ProductAttribute

Author: Sardorbek-Zayniyev

drfecommerce/product/models.py

@@ -91,6 +91,26 @@ class ProductLineAttributeValue(models.Model):
     class Meta:
         unique_together = ("attribute_value", "product_line")
 
+    def clean(self):
+        qs = (
+            ProductLineAttributeValue.objects.filter(
+                attribute_value=self.attribute_value
+            )
+            .filter(product_line=self.product_line)
+            .exists()
+        )
+        if not qs:
+            iqs = Attribute.filter(
+                attribute_value__product_line_attribute_value=self.product_line
+            ).values_list("pk", flat=True)
+
+            if self.attribute_value.attribute.id in list(iqs):
+                raise ValidationError("Duplicate attribute exists")
+
+        def save(self, *args, **kwargs):
+            self.full_clean()
+            return super(ProductLine, self).save(*args, **kwargs)
+
 
 class ProductLine(models.Model):
     product = models.ForeignKey(
@@ -101,8 +121,7 @@ class ProductLine(models.Model):
         through="ProductLineAttributeValue",
         related_name="product_line_attribute_value",
     )
-    product_type = models.ForeignKey(
-        "ProductType", on_delete=models.PROTECT)
+    product_type = models.ForeignKey("ProductType", on_delete=models.PROTECT)
 
     price = models.DecimalField(decimal_places=2, max_digits=5)
     sku = models.CharField(max_length=100)

drfecommerce/product/serializers.py

@@ -1,6 +1,14 @@
 from rest_framework import serializers
 
-from .models import Category, Brand, Product, ProductLine, ProductImage, Attribute, AttributeValue
+from .models import (
+    Category,
+    Brand,
+    Product,
+    ProductLine,
+    ProductImage,
+    Attribute,
+    AttributeValue,
+)
 
 
 class CategorySerializer(serializers.ModelSerializer):
@@ -28,34 +36,36 @@ class Meta:
 class AttributeSerializer(serializers.ModelSerializer):
     class Meta:
         model = Attribute
-        fields = ('id', 'name')
+        fields = ("id", "name")
 
 
 class AttributeValueSerializer(serializers.ModelSerializer):
     attribute = AttributeSerializer(many=False)
 
     class Meta:
         model = AttributeValue
-        fields = ('attribute', "attribute_value")
+        fields = ("attribute", "attribute_value")
 
 
 class ProductLineSerializer(serializers.ModelSerializer):
 
     class Meta:
         model = ProductLine
-        fields = ("price", "sku", "stock_qty", "order",
-                  "product_image", "attribute_value", )
+        fields = (
+            "price",
+            "sku",
+            "stock_qty",
+            "order",
+            "product_image",
+            "attribute_value",
+        )
 
         def to_representation(self, instance):
             data = super().to_representation(instance)
-            av_data = data.pop('attribute')
+            av_data = data.pop("attribute")
             attr_values = {}
             for key in av_data:
-                attr_values.update(
-                    {
-                        key['attribute']['id']: key['attribute_value']
-                    }
-                )
+                attr_values.update({key["attribute"]["id"]: key["attribute_value"]})
             data.update({"specification": attr_values})
             return data