Fix pickling state (#6245)

Co-authored-by: Simon Høxbro Hansen <[email protected]>

holoviews/core/dimension.py

@@ -716,37 +716,27 @@ def __setstate__(self, d):
         "Restores options applied to this object."
         d = param_aliases(d)
 
-        # Backwards compatibility for objects before id was made a property
-        opts_id = d['_id'] if '_id' in d else d.pop('id', None)
-        try:
-            load_options = Store.load_counter_offset is not None
-            if load_options:
-                matches = [k for k in d if k.startswith('_custom_option')]
-                for match in matches:
-                    custom_id = int(match.split('_')[-1])+Store.load_counter_offset
-                    if not isinstance(d[match], dict):
-                        # Backward compatibility before multiple backends
-                        backend_info = {'matplotlib':d[match]}
-                    else:
-                        backend_info = d[match]
-                    for backend, info in  backend_info.items():
-                        if backend not in Store._custom_options:
-                            Store._custom_options[backend] = {}
-                        Store._custom_options[backend][custom_id] = info
-                    if backend_info:
-                        if custom_id not in Store._weakrefs:
-                            Store._weakrefs[custom_id] = []
-                        ref = weakref.ref(self, partial(cleanup_custom_options, custom_id))
-                        Store._weakrefs[opts_id].append(ref)
-                    d.pop(match)
-
-                if opts_id is not None:
-                    opts_id += Store.load_counter_offset
-        except Exception:
-            self.param.warning("Could not unpickle custom style information.")
-        d['_id'] = opts_id
+        load_options = Store.load_counter_offset is not None
+        if load_options:
+            matches = [k for k in d if k.startswith('_custom_option')]
+            for match in matches:
+                custom_id = int(match.split('_')[-1])+Store.load_counter_offset
+                for backend, info in d[match].items():
+                    if backend not in Store._custom_options:
+                        Store._custom_options[backend] = {}
+                    Store._custom_options[backend][custom_id] = info
+                if d[match]:
+                    if custom_id not in Store._weakrefs:
+                        Store._weakrefs[custom_id] = []
+                    ref = weakref.ref(self, partial(cleanup_custom_options, custom_id))
+                    Store._weakrefs[d["_id"]].append(ref)
+                d.pop(match)
+
+            if d["_id"] is not None:
+                d["_id"] += Store.load_counter_offset
+
         self.__dict__.update(d)
-        super().__setstate__({})
+        super().__setstate__(d)
 
 
 class Dimensioned(LabelledData):

holoviews/tests/core/test_dimensioned.py

@@ -1,8 +1,10 @@
 import gc
+import pickle
 
 from holoviews.core.element import Element
 from holoviews.core.options import Keywords, Options, OptionTree, Store
 from holoviews.core.spaces import HoloMap
+from holoviews.element.chart import Curve
 
 from ..utils import LoggingComparisonTestCase
 
@@ -247,3 +249,11 @@ def test_opts_clear_cleans_unused_tree(self):
         ExampleElement([]).opts(style_opt1='A').opts.clear()
         custom_options = Store._custom_options['backend_1']
         self.assertEqual(len(custom_options), 0)
+
+class TestGetSetState:
+
+    def test_pickle_roundtrip(self):
+        curve = Curve([0, 1, 2], kdims=["XAXIS"])
+        roundtrip_curve = pickle.loads(pickle.dumps(curve))
+        assert curve.kdims == roundtrip_curve.kdims
+        assert curve.vdims == roundtrip_curve.vdims