LIL-229. Add soft delete functional for Course & Lesson model

apps/course/migrations/0031_auto_20180213_0906.py

@@ -0,0 +1,23 @@
+# Generated by Django 2.0.2 on 2018-02-13 09:06
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('course', '0030_auto_20180212_0537'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='course',
+            name='deactivated_at',
+            field=models.DateTimeField(blank=True, default=None, null=True),
+        ),
+        migrations.AddField(
+            model_name='lesson',
+            name='deactivated_at',
+            field=models.DateTimeField(blank=True, default=None, null=True),
+        ),
+    ]

apps/course/models.py

@@ -7,6 +7,8 @@ from django.contrib.auth import get_user_model
 from django.urls import reverse_lazy
 from polymorphic_tree.models import PolymorphicMPTTModel, PolymorphicTreeForeignKey
 
+from project.mixins import BaseModel, DeactivatedMixin
+
 from .manager import CategoryQuerySet
 
 from apps.content.models import ImageObject, Gallery
@@ -25,7 +27,7 @@ def default_slug():
     return str(uuid4())
 
 
-class Course(models.Model):
+class Course(BaseModel, DeactivatedMixin):
     PENDING = 0
     PUBLISHED = 1
     ARCHIVED = 2
@@ -141,7 +143,7 @@ class Category(models.Model):
         ordering = ['title']
 
 
-class Lesson(models.Model):
+class Lesson(BaseModel, DeactivatedMixin):
     title = models.CharField('Название урока', max_length=100)
     short_description = models.TextField('Краткое описание урока')
     course = models.ForeignKey(

project/mixins.py

@@ -0,0 +1,38 @@
+from django.db import models
+from django.utils import timezone
+
+
+class BaseModel(models.Model):
+
+    class Meta:
+        abstract = True
+
+
+class DeactivatedQueryset(models.Manager):
+
+    def allow_delete(self):
+        super().delete()
+
+    def delete(self):
+        count = self.count()
+        self.filter(deactivated_at__isnull=True).update(
+            deactivated_at=timezone.now()
+        )
+        return (count, None)
+
+
+class DeactivatedMixin(models.Model):
+    deactivated_at = models.DateTimeField(null=True, blank=True, default=None)
+
+    objects = DeactivatedQueryset()
+
+    class Meta:
+        abstract = True
+
+    def allow_delete(self, using=None, keep_parents=False):
+        super().delete(using=using, keep_parents=keep_parents)
+
+    def delete(self, using=None, keep_parents=False):
+        if not self.deactivated_at:
+            self.deactivated_at = timezone.now()
+            self.save()