Handle ndarray data before JSON serialization

dashipy/dashipy/components/plot.py

@@ -14,10 +14,7 @@ class Plot(Component):
     def to_dict(self) -> dict[str, Any]:
         d = super().to_dict()
         if self.figure is not None:
-            # TODO: this is stupid, but if using self.figure.to_dict()
-            #   for plotly.express figures we get
-            #   TypeError: Object of type ndarray is not JSON serializable
-            d.update(figure=json.loads(self.figure.to_json()))
+            d.update(figure=self.figure.to_dict())
         else:
             d.update(figure=None)
         return d

dashipy/dashipy/server.py

@@ -1,5 +1,6 @@
 import asyncio
 import importlib
+import json
 import traceback
 from typing import Any
 
@@ -12,6 +13,7 @@
 from dashipy.context import Context
 from dashipy.contribs import Panel
 from dashipy.lib import Extension, Contribution
+from dashipy.utils import NumpyJSONEncoder
 
 DASHI_CONTEXT_KEY = "dashi.context"
 DASHI_EXTENSIONS_KEY = "dashi.extensions"
@@ -117,7 +119,7 @@ def render_layout(
             return
 
         self.set_header("Content-Type", "text/json")
-        self.write({"result": component.to_dict()})
+        self.write(json.dumps({"result":  component.to_dict()}, cls=NumpyJSONEncoder))
 
 
 class CallbackHandler(DashiHandler):
@@ -172,7 +174,7 @@ def post(self):
             )
 
         self.set_header("Content-Type", "text/json")
-        self.write({"result": change_requests})
+        self.write(json.dumps({"result":  change_requests}, cls=NumpyJSONEncoder))
 
 
 def print_usage(app, port):

dashipy/dashipy/utils/__init__.py

@@ -0,0 +1 @@
+from .json_encoder import NumpyJSONEncoder

dashipy/dashipy/utils/json_encoder.py

@@ -0,0 +1,9 @@
+import json
+import numpy as np
+
+
+class NumpyJSONEncoder(json.JSONEncoder):
+    def default(self, obj):
+        if isinstance(obj, np.ndarray):
+            return obj.tolist()
+        return super().default(obj)