Fix serialization issue

Signed-off-by: martinRenou <[email protected]>

Author: martinRenou

ipydatagrid/datagrid.py

@@ -189,6 +189,18 @@ def _data_to_json(x, obj):
 }
 
 
+def _widgets_dict_to_json(x, obj):
+    return {
+        str(k): widget_serialization["to_json"](v, obj) for k, v in x.items()
+    }
+
+
+_widgets_dict_serialization = {
+    "from_json": widget_serialization["from_json"],
+    "to_json": _widgets_dict_to_json,
+}
+
+
 class DataGrid(DOMWidget):
 
     """A Grid Widget with filter, sort and selection capabilities.
@@ -322,7 +334,7 @@ class DataGrid(DOMWidget):
     _data = Dict().tag(sync=True, **_data_serialization)
 
     renderers = Dict(Instance(CellRenderer)).tag(
-        sync=True, **widget_serialization
+        sync=True, **_widgets_dict_serialization
     )
     default_renderer = Instance(CellRenderer).tag(
         sync=True, **widget_serialization
@@ -336,14 +348,17 @@ class DataGrid(DOMWidget):
     selection_mode = Enum(
         default_value="none", values=["row", "column", "cell", "none"]
     ).tag(sync=True)
-    selections = List(Dict()).tag(sync=True, **widget_serialization)
+    selections = List(Dict()).tag(sync=True)
     editable = Bool(False).tag(sync=True)
     column_widths = Dict({}).tag(sync=True, **_data_serialization)
-    grid_style = Dict(allow_none=True).tag(sync=True, **widget_serialization)
+    column_widths = Dict({}).tag(sync=True)
+    grid_style = Dict(allow_none=True).tag(
+        sync=True, **_widgets_dict_serialization
+    )
     auto_fit_columns = Bool(False).tag(sync=True)
     auto_fit_params = Dict(
         {"area": "all", "padding": 30, "numCols": None}, allow_none=False
-    ).tag(sync=True, **widget_serialization)
+    ).tag(sync=True)
 
     def __init__(self, dataframe, **kwargs):
         # Setting default index name if not explicitly

tests/test_datagrid.py

@@ -1,7 +1,8 @@
 import pandas as pd
 import pytest
 
-from ipydatagrid import DataGrid
+from ipydatagrid import DataGrid, TextRenderer
+from ipydatagrid.datagrid import _widgets_dict_serialization
 
 
 @pytest.fixture()
@@ -236,3 +237,20 @@ def test_setting_column_widths_on_multiindex_grid():
     col_widths = {("Parent Column", "SubCol 1"): 100}
 
     grid.column_widths = col_widths
+
+
+def test_renderers_serialization():
+    col_names = [("Parent Column", "SubCol 1"), ("Parent Column", "SubCol 2")]
+    df = pd.DataFrame(data={i: [1, 2, 3] for i in col_names}, columns=col_names)
+
+    grid = DataGrid(
+        df,
+        layout={"height": "200px"},
+        renderers={("Parent Column", "SubCol 1"): TextRenderer()},
+    )
+
+    serialized_renderers = _widgets_dict_serialization["to_json"](
+        grid.renderers, grid
+    )
+
+    assert isinstance(list(serialized_renderers.keys())[0], str)