refactor: drop django-mptt in favour of django-tree-queries

emeis/core/management/commands/create_scope.py

@@ -3,7 +3,6 @@
 from django.core.management.base import BaseCommand
 
 from emeis.core.models import ACL, Role, Scope, User
-from emeis.core.utils import rebuild_mptt_model
 
 
 class Command(BaseCommand):
@@ -78,7 +77,6 @@ def handle(self, *args, **options):
             options["name"] = json.loads(options["name"])
 
         new_scope = Scope.objects.create(name=options["name"], parent=parent)
-        rebuild_mptt_model(Scope)
         out_info["scope_id"] = str(new_scope.pk)
 
         if options["user"]:

emeis/core/migrations/0001_initial.py

@@ -6,7 +6,6 @@
 import django.utils.timezone
 import localized_fields.fields.char_field
 import localized_fields.fields.text_field
-import mptt.fields
 from django.conf import settings
 from django.db import migrations, models
 
@@ -224,7 +223,7 @@ class Migration(migrations.Migration):
                 ),
                 (
                     "parent",
-                    mptt.fields.TreeForeignKey(
+                    models.ForeignKey(
                         blank=True,
                         null=True,
                         on_delete=django.db.models.deletion.SET_NULL,

emeis/core/migrations/0009_alter_scope_parent.py

@@ -1,8 +1,7 @@
 # Generated by Django 3.2.12 on 2022-04-21 07:24
 
-from django.db import migrations
 import django.db.models.deletion
-import mptt.fields
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):
@@ -14,7 +13,7 @@ class Migration(migrations.Migration):
         migrations.AlterField(
             model_name="scope",
             name="parent",
-            field=mptt.fields.TreeForeignKey(
+            field=models.ForeignKey(
                 blank=True,
                 null=True,
                 on_delete=django.db.models.deletion.CASCADE,

emeis/core/migrations/0010_scope_full_name.py

@@ -1,7 +1,7 @@
 # Generated by Django 3.2.15 on 2022-09-23 09:13
 
-from django.db import migrations
 import localized_fields.fields.char_field
+from django.db import migrations
 
 from emeis.core import models
 

emeis/core/migrations/0011_mptt_to_tree_queries.py

@@ -0,0 +1,45 @@
+# Generated by Django 3.2.25 on 2024-06-03 14:17
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("emeis_core", "0010_scope_full_name"),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name="scope",
+            options={"ordering": ["full_name"]},
+        ),
+        migrations.RemoveField(
+            model_name="scope",
+            name="level",
+        ),
+        migrations.RemoveField(
+            model_name="scope",
+            name="lft",
+        ),
+        migrations.RemoveField(
+            model_name="scope",
+            name="rght",
+        ),
+        migrations.RemoveField(
+            model_name="scope",
+            name="tree_id",
+        ),
+        migrations.AlterField(
+            model_name="scope",
+            name="parent",
+            field=models.ForeignKey(
+                blank=True,
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="children",
+                to="emeis_core.scope",
+                verbose_name="parent",
+            ),
+        ),
+    ]

emeis/core/models.py

@@ -10,7 +10,7 @@
 from django.utils import timezone, translation
 from django.utils.translation import gettext_lazy as _
 from localized_fields.fields import LocalizedCharField, LocalizedTextField
-from mptt.models import MPTTModel, TreeForeignKey
+from tree_queries.models import TreeNode, TreeQuerySet
 
 
 def make_uuid():
@@ -158,7 +158,7 @@ def is_authenticated(self):
         return True
 
 
-class Scope(MPTTModel, UUIDModel):
+class Scope(TreeNode, UUIDModel):
     name = LocalizedCharField(_("scope name"), blank=False, null=False, required=False)
 
     full_name = LocalizedCharField(
@@ -168,20 +168,21 @@ class Scope(MPTTModel, UUIDModel):
     description = LocalizedTextField(
         _("scope description"), null=True, blank=True, required=False
     )
-    parent = TreeForeignKey(
-        "self",
-        on_delete=models.CASCADE,
-        null=True,
-        blank=True,
-        related_name="children",
-    )
     is_active = models.BooleanField(default=True)
 
+    objects = TreeQuerySet.as_manager(with_tree_fields=True)
+
+    def save(self, *args, **kwargs):
+        # django-tree-queries does validation in TreeNode.clean(), which is not
+        # called by DRF (only by django forms), so we have to do this here
+        self.clean()
+        return super().save(*args, **kwargs)
+
     def __str__(self):
         return f"{type(self).__name__} ({self.full_name}, pk={self.pk})"
 
     class Meta:
-        ordering = ["full_name"]
+        ordering = ["name"]
 
 
 @receiver(pre_save, sender=Scope)

emeis/core/serializers.py

@@ -33,6 +33,10 @@ class Meta:
 
 
 class MyACLSerializer(BaseSerializer):
+    scope = serializers.ResourceRelatedField(
+        queryset=Scope.objects.all(), required=False, many=False
+    )
+
     included_serializers = {
         "scope": "emeis.core.serializers.ScopeSerializer",
         "role": "emeis.core.serializers.RoleSerializer",
@@ -73,6 +77,22 @@ class Meta:
 
 
 class ScopeSerializer(BaseSerializer):
+    level = serializers.SerializerMethodField()
+
+    def get_level(self, obj):
+        depth = getattr(obj, "tree_depth", None)
+        if depth is not None:
+            return depth
+
+        # Note: This should only happen on CREATE, never in GET (Either list,
+        # detail, or include!) In CREATE, it's a new object that doesn't come
+        # from a QS
+
+        # Sometimes, the model object may come out of a non-django-tree-queries
+        # QS, and thus would not have the `tree_*` attributes amended. Then we
+        # need to go the "slow path"
+        return obj.ancestors().count()
+
     class Meta:
         model = Scope
         fields = BaseSerializer.Meta.fields + (
@@ -83,7 +103,7 @@ class Meta:
             "full_name",
             "is_active",
         )
-        read_only_fields = ["full_name"]
+        read_only_fields = ["full_name", "level"]
 
 
 class PermissionSerializer(BaseSerializer):
@@ -111,6 +131,9 @@ class Meta:
 
 
 class ACLSerializer(BaseSerializer):
+    scope = serializers.ResourceRelatedField(
+        queryset=Scope.objects.all(), required=False, many=False
+    )
     included_serializers = {
         "user": UserSerializer,
         "scope": ScopeSerializer,