Add migration to handle layer tree

.gitignore

@@ -121,3 +121,6 @@ dmypy.json
 
 # Pyre type checker
 .pyre/
+
+# IDE
+.vscode

terra_layer/migrations/0045_add_tree_2_scene.py

@@ -9,26 +9,79 @@
 class Migration(migrations.Migration):
 
     dependencies = [
-        ('terra_layer', '0044_order'),
+        ("terra_layer", "0044_order"),
     ]
 
     operations = [
         migrations.AlterModelOptions(
-            name='layer',
-            options={'ordering': ('order', 'name')},
+            name="layer", options={"ordering": ("order", "name")},
         ),
         migrations.AddField(
-            model_name='scene',
-            name='tree',
-            field=django.contrib.postgres.fields.jsonb.JSONField(default=list, validators=[terra_layer.schema.JSONSchemaValidator(limit_value={'$id': 'http://terralego.com/scene_layertree.json', '$schema': 'http://json-schema.org/draft-07/schema#', 'definitions': {}, 'items': {'$id': '#/items', 'dependencies': {'group': ['children', 'label']}, 'properties': {'children': {'$ref': '#'}, 'expanded': {'$id': '#/items/properties/expanded', 'default': False, 'examples': [True], 'title': 'The expanded status in admin. Not used yet', 'type': 'boolean'}, 'geolayer': {'$id': '#/items/properties/geolayer', 'default': 0, 'examples': [96], 'title': 'The geolayer id', 'type': 'integer'}, 'group': {'$id': '#/items/properties/group', 'default': False, 'examples': [True], 'title': "The group name. Present if it's a group.", 'type': 'boolean'}, 'label': {'$id': '#/items/properties/label', 'default': '', 'examples': ['My Group'], 'pattern': '^(.*)$', 'title': 'The group name', 'type': 'string'}}, 'required': [], 'title': 'Layer tree item', 'type': 'object'}, 'title': 'Scene layer tree schema', 'type': 'array'})]),
+            model_name="scene",
+            name="tree",
+            field=django.contrib.postgres.fields.jsonb.JSONField(
+                default=list,
+                validators=[
+                    terra_layer.schema.JSONSchemaValidator(
+                        limit_value={
+                            "$id": "http://terralego.com/scene_layertree.json",
+                            "$schema": "http://json-schema.org/draft-07/schema#",
+                            "definitions": {},
+                            "items": {
+                                "$id": "#/items",
+                                "dependencies": {"group": ["children", "label"]},
+                                "properties": {
+                                    "children": {"$ref": "#"},
+                                    "expanded": {
+                                        "$id": "#/items/properties/expanded",
+                                        "default": False,
+                                        "examples": [True],
+                                        "title": "The expanded status in admin. Not used yet",
+                                        "type": "boolean",
+                                    },
+                                    "geolayer": {
+                                        "$id": "#/items/properties/geolayer",
+                                        "default": 0,
+                                        "examples": [96],
+                                        "title": "The geolayer id",
+                                        "type": "integer",
+                                    },
+                                    "group": {
+                                        "$id": "#/items/properties/group",
+                                        "default": False,
+                                        "examples": [True],
+                                        "title": "The group name. Present if it's a group.",
+                                        "type": "boolean",
+                                    },
+                                    "label": {
+                                        "$id": "#/items/properties/label",
+                                        "default": "",
+                                        "examples": ["My Group"],
+                                        "pattern": "^(.*)$",
+                                        "title": "The group name",
+                                        "type": "string",
+                                    },
+                                },
+                                "required": [],
+                                "title": "Layer tree item",
+                                "type": "object",
+                            },
+                            "title": "Scene layer tree schema",
+                            "type": "array",
+                        }
+                    )
+                ],
+            ),
         ),
         migrations.AlterField(
-            model_name='layer',
-            name='group',
-            field=models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='layers', to='terra_layer.LayerGroup'),
-        ),
-        migrations.AlterUniqueTogether(
-            name='layergroup',
-            unique_together=set(),
+            model_name="layer",
+            name="group",
+            field=models.ForeignKey(
+                null=True,
+                on_delete=django.db.models.deletion.SET_NULL,
+                related_name="layers",
+                to="terra_layer.LayerGroup",
+            ),
         ),
+        migrations.AlterUniqueTogether(name="layergroup", unique_together=set(),),
     ]

terra_layer/migrations/0046_migrate_layer_groups_2_tree.py

@@ -0,0 +1,87 @@
+# Generated by Django 2.2.7 on 2019-12-12 10:29
+
+from django.db import migrations, transaction
+
+
+def layer2dict(layer):
+    return {"geolayer": layer.id, "label": layer.name}
+
+
+def group2dict(group):
+    children = []
+
+    for sub_group in group.children.all():
+        children.append(group2dict(sub_group))
+
+    for sub_layer in group.layers.all():
+        children.append(layer2dict(sub_layer))
+
+    return {
+        "label": group.label,
+        "group": True,
+        "children": children,
+        "exclusive": group.exclusive,
+        "selectors": group.selectors,
+        "settings": group.settings,
+    }
+
+
+@transaction.atomic
+def group2scene_tree(apps, schema_editor):
+    Scene = apps.get_model("terra_layer", "Scene")
+    LayerGroup = apps.get_model("terra_layer", "LayerGroup")
+    Layer = apps.get_model("terra_layer", "Layer")
+
+    def tree2models(scene, current_node, parent=None, order=0):
+        """
+        Copied and adapted from the one in `models.py` to avoid further evolutions.
+        """
+
+        if not parent:
+            # Create a default unique parent group that is ignored at export
+            parent = LayerGroup.objects.create(view=scene, label="Root")
+
+        if isinstance(current_node, list):
+            for idx, child in enumerate(current_node):
+                tree2models(scene, current_node=child, parent=parent, order=idx)
+
+        elif "group" in current_node:
+            # Handle groups
+            group = parent.children.create(
+                view=scene,
+                label=current_node["label"],
+                exclusive=current_node.get("exclusive", False),
+                order=order,
+            )
+
+            if "children" in current_node:
+                tree2models(scene, current_node=current_node["children"], parent=group)
+
+        elif "geolayer" in current_node:
+            # Handle layers
+            layer = Layer.objects.get(pk=current_node["geolayer"])
+            layer.group = parent
+            layer.order = order
+            layer.save()
+
+    for scene in Scene.objects.all():
+        tree = []
+        for lg in LayerGroup.objects.filter(view=scene, parent=None):
+            tree.append(group2dict(lg))
+        # There is no sublayer at level 0 so no need to handle them
+        scene.tree = tree
+
+        scene.save()
+        scene.layer_groups.all().delete()  # Clear all groups to generate brand new one
+        tree2models(scene, tree)
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("terra_layer", "0045_add_tree_2_scene"),
+    ]
+
+    operations = [
+        migrations.RunPython(group2scene_tree),
+    ]

terra_layer/schema.py

@@ -59,6 +59,23 @@ def compare(self, a, b):
                 "default": False,
                 "examples": [True],
             },
+            "selectors": {
+                "$id": "#/items/properties/selectors",
+                "type": ["array", "null"],
+                "title": "The selectors for this group",
+            },
+            "settings": {
+                "$id": "#/items/properties/settings",
+                "type": "object",
+                "title": "The settings of group",
+            },
+            "group": {
+                "$id": "#/items/properties/exclusive",
+                "type": "boolean",
+                "title": "Is the group exclusive ?",
+                "default": False,
+                "examples": [True],
+            },
             "children": {"$ref": "#"},
         },
     },

terra_layer/views/layers.py

@@ -36,7 +36,7 @@ def get_serializer_class(self,):
             return SceneDetailSerializer
         return SceneListSerializer
 
-    def check_layer_status(self, current_node):
+    def check_layer_status(self, view_id, current_node):
         """
         Check all layers in tree to valide existence and scene ownership.
         Recursive process.
@@ -55,22 +55,24 @@ def check_layer_status(self, current_node):
                     )
 
                 # Is layer owned by another scene ?
-                if layer.group and layer.group.view != self:
+                if layer.group and layer.group.view.id != view_id:
                     raise ValidationError(
                         f"Layer {item['geolayer']} can't be stolen from another scene"
                     )
             else:
                 # And we start with the new node
-                self.check_layer_status(item["children"])
+                self.check_layer_status(view_id, item["children"])
 
     def perform_update(self, serializer):
         if serializer.is_valid():
-            self.check_layer_status(serializer.validated_data.get("tree", []))
+            self.check_layer_status(
+                serializer.instance.id, serializer.validated_data.get("tree", [])
+            )
             serializer.save()
 
     def perform_create(self, serializer):
         if serializer.is_valid():
-            self.check_layer_status(serializer.validated_data.get("tree", []))
+            self.check_layer_status(None, serializer.validated_data.get("tree", []))
             serializer.save()