fix: Don't error if data does not have name attribute (#7655)

* fix: Don't error if data does not have name attribute

* Add test

* rename to not error?

panel/reactive.py

@@ -2174,7 +2174,7 @@ def _update_model(
                 from .io.datamodel import create_linked_datamodel
                 old = getattr(model.data, prop)
                 if isinstance(old, list):
-                    mapping = {o.name: o for o in old}
+                    mapping = {getattr(o, "name", o): o for o in old}
                     vals = []
                     for vs in v:
                         if (vname:=f"{root.ref['id']}-{id(vs)}") in mapping:

panel/tests/test_reactive.py

@@ -808,3 +808,15 @@ def test_reactive_design_stylesheets_update(document, comm):
 
     assert len(model.stylesheets) == 5
     assert model.stylesheets[-1] == widget.stylesheets[0]
+
+
+def test_reactive_attribute_no_name(document, comm):
+    # Regression: https://github.com/holoviz/panel/pull/7655
+    class CustomComponent2(ReactiveHTML):
+        groups = param.ListSelector(default=["A"], objects=["A", "B"])
+        _scripts = {"groups": "console.log(data.groups)"}
+
+    component = CustomComponent2()
+    component.get_root(document, comm)
+    # Should not error out
+    component.groups = []