Merge pull request plotly#2491 from plotly/fix/plotly#2488

Fix clientside inline function name.

CHANGELOG.md

@@ -2,6 +2,12 @@
 All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
+## [UNRELEASED]
+
+## Fixed
+
+- [#2491](https://github.com/plotly/dash/pull/2491) Fix clientside inline function name not found, fix [#2488](https://github.com/plotly/dash/issues/2488)
+
 ## [2.9.2] - 2023-03-29
 
 ## Fixed

dash/_callback.py

@@ -1,5 +1,5 @@
 import collections
-import uuid
+import hashlib
 from functools import wraps
 
 import flask
@@ -534,8 +534,8 @@ def register_clientside_callback(
     # name, then inject the code.
     if isinstance(clientside_function, str):
         namespace = "_dashprivate_clientside_funcs"
-        # Just make sure every function has a different name if not provided.
-        function_name = uuid.uuid4().hex
+        # Create a hash from the function, it will be the same always
+        function_name = hashlib.md5(clientside_function.encode("utf-8")).hexdigest()
 
         inline_scripts.append(
             _inline_clientside_template.format(

tests/integration/clientside/test_clientside_restarts.py

@@ -0,0 +1,55 @@
+import pytest
+from dash import Dash, html, Output, Input
+
+
+@pytest.mark.skip(reason="Hot-reload & clientside callbacks doesn't work properly")
+def test_clrs001_clientside_inline_restarts(dash_duo_mp):
+    # FIXME find another way to test clientside callbacks restarts
+    reloads = 0
+
+    def create_app():
+        nonlocal reloads
+
+        app = Dash(__name__)
+
+        app.layout = html.Div([
+            html.Button("Click", id="click"),
+            html.Div(id="output"),
+            html.Div(reloads, id="reload")
+        ])
+
+        app.clientside_callback(
+            "(n_clicks) => `clicked ${n_clicks}`",
+            Output("output", "children"),
+            Input("click", "n_clicks"),
+            prevent_initial_call=True
+        )
+        reloads += 1
+        return app
+
+    hot_reload_settings = dict(
+        dev_tools_hot_reload=True,
+        dev_tools_ui=True,
+        dev_tools_serve_dev_bundles=True,
+        dev_tools_hot_reload_interval=0.1,
+        dev_tools_hot_reload_max_retry=100,
+    )
+
+    dash_duo_mp.start_server(
+        create_app(),
+        **hot_reload_settings
+    )
+    dash_duo_mp.find_element("#click").click()
+    dash_duo_mp.wait_for_text_to_equal("#output", "clicked 1")
+
+    dash_duo_mp.server.stop()
+
+    dash_duo_mp.start_server(
+        create_app(),
+        navigate=False,
+        **hot_reload_settings
+    )
+    dash_duo_mp.wait_for_text_to_equal("#reload", "1")
+    dash_duo_mp.find_element("#click").click()
+    # reloaded so 1 again.
+    dash_duo_mp.wait_for_text_to_equal("#output", "clicked 1")