some fields validation and model cleaning

common/fields.py

@@ -0,0 +1,29 @@
+from django.core.exceptions import ValidationError
+from django.db import models
+
+
+class UpperCaseCharField(models.CharField):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    def get_prep_value(self, value):
+        value = super().get_prep_value(value)
+        if value is not None:
+            return value.upper()
+        return value
+
+
+class ContainerNumberField(UpperCaseCharField):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    def get_prep_value(self, value):
+        value = super().get_prep_value(value)
+        if value is not None:
+            return value.upper()
+        return value
+
+    def validate(self, value, model_instance):
+        super().validate(value, model_instance)
+        if value and len(value) != 11:
+            raise ValidationError('Container number must be exactly 11 characters long.')

common/models.py

@@ -1,22 +1,39 @@
 from django.db import models
+from django.core.exceptions import ValidationError
+
+from common.fields import UpperCaseCharField
+
 
 # Create your models here.
 class NomenclatureBaseModel(models.Model):
-    name = models.CharField(max_length=100, unique=True)
-    short_name = models.CharField(max_length=5, null=True, blank=True)
+    name = UpperCaseCharField(max_length=100)
+    short_name = UpperCaseCharField(max_length=5, null=True, blank=True)
     description = models.TextField(blank=True, null=True)
     active = models.BooleanField(default=True)
+
     class Meta:
         abstract = True
         ordering = ['name']
-        app_label = 'common'
+
     def __str__(self):
         return self.name
 
+    def clean(self):
+        if not self.name:
+            raise ValidationError('Name cannot be empty.')
+        if self.short_name and len(self.short_name) > 5:
+            raise ValidationError('Short name cannot exceed 5 characters.')
+        if self.description and len(self.description) > 255:
+            raise ValidationError('Description cannot exceed 255 characters.')
+
 
 class CompanyModel(NomenclatureBaseModel):
-    class Meta:
-        app_label = 'common'
+    def clean(self):
+        super().clean()
+        if CompanyModel.objects.filter(name=self.name, active=True).exclude(id=self.id).exists():
+            raise ValidationError(f'Company with name {self.name} already exists and is active.')
+        if CompanyModel.objects.filter(short_name=self.short_name, active=True).exclude(id=self.id).exists():
+            raise ValidationError(f'Company with short name {self.short_name} already exists and is active.')
 
 
 class LinesModel(NomenclatureBaseModel):
@@ -26,8 +43,13 @@ class LinesModel(NomenclatureBaseModel):
         related_name='line_company'
     )
 
-    class Meta:
-        app_label = 'common'
+    def clean(self):
+        super().clean()
+        if LinesModel.objects.filter(name=self.name, active=True).exclude(id=self.id).exists():
+            raise ValidationError(f'Line with name {self.name} already exists and is active.')
+        if LinesModel.objects.filter(short_name=self.short_name, active=True).exclude(id=self.id).exists():
+            raise ValidationError(f'Line with short name {self.short_name} already exists and is active.')
+
 
 class OperationModel(NomenclatureBaseModel):
     ...
@@ -50,4 +72,4 @@ class ContainerTypeModel(models.Model):
         app_label = 'common'
 
     def __str__(self):
-        return self.name
+        return self.name