Add roots() method in lots

ereuse_devicehub/resources/inventory.py

@@ -7,6 +7,7 @@ from sqlalchemy import Column
 
 from ereuse_devicehub.resources.device.models import Device
 from ereuse_devicehub.resources.event.models import Rate
+from ereuse_devicehub.resources.lot.models import Lot
 from ereuse_devicehub.resources.schemas import Thing
 from ereuse_devicehub.resources.tag import Tag
 from teal.query import Between, FullTextSearch, ILike, Join, Or, Query, Sort, SortField
@@ -97,7 +98,7 @@ class InventoryView(View):
             .paginate(page=args['page'], per_page=30)  # type: Pagination
         inventory = {
             'devices': app.resources[Device.t].schema.dump(devices.items, many=True, nested=1),
-            'groups': [],
+            'lots': Lot.roots(),
             'widgets': {},
             'pagination': {
                 'page': devices.page,

ereuse_devicehub/resources/lot/models.py

@@ -48,6 +48,11 @@ class Lot(Thing):
     def __contains__(self, child: 'Lot'):
         return Edge.has_lot(self.id, child.id)
 
+    @classmethod
+    def roots(cls):
+        """Gets the lots that are not under any other lot."""
+        return set(cls.query.join(cls.edges).filter(db.func.nlevel(Edge.path) == 1).all())
+
     def __repr__(self) -> str:
         return '<Lot {0.name} devices={0.devices!r}>'.format(self)
 

tests/test_lot.py

@@ -168,3 +168,16 @@ def test_lot_unite_graphs():
     l2.remove_child(l4)
     assert l4 not in l2 and l5 not in l2 and l6 not in l2 and l7 not in l2 and l8 not in l2
     assert l4 not in l3 and l5 not in l3 and l6 not in l3 and l7 not in l3 and l8 not in l3
+
+
+@pytest.mark.usefixtures(conftest.auth_app_context.__name__)
+def test_lot_roots():
+    """Tests getting the method Lot.roots."""
+    lots = Lot('1'), Lot('2'), Lot('3')
+    l1, l2, l3 = lots
+    db.session.add_all(lots)
+    db.session.flush()
+
+    assert Lot.roots() == {l1, l2, l3}
+    l1.add_child(l2)
+    assert Lot.roots() == {l1, l3}