Mitigate UI refresh slowdown with additional binding for initial value

Author: tupui

panel/app.py

@@ -264,15 +264,19 @@ def csv_data(
 interactive_file = pn.bind(load_data, text_fname)
 
 interactive_column_output = pn.bind(column_output, interactive_file)
-selector_output = pn.widgets.Select(name="Output", options=interactive_column_output)
+# hack to make the default selection faster
+interactive_output_ = pn.bind(lambda x: x[0], interactive_column_output)
+selector_output = pn.widgets.Select(
+    name="Output", value=interactive_output_, options=interactive_column_output
+)
 interactive_output = pn.bind(filtered_output, interactive_file, selector_output)
 
 interactive_column_input = pn.bind(column_inputs, interactive_file, selector_output)
 selector_inputs_sensitivity = pn.widgets.MultiSelect(
     name="Inputs", value=interactive_column_input, options=interactive_column_input
 )
 interactive_inputs = pn.bind(
-    filtered_output, interactive_file, selector_inputs_sensitivity
+    filtered_inputs, interactive_file, selector_inputs_sensitivity
 )
 
 interactive_sensitivity_indices = pn.bind(