reduce boilerplate in basic_hello_structure_interactive.py using prevent_initial_callbacks

Author: janosh

crystal_toolkit/apps/examples/basic_hello_structure_interactive.py

@@ -4,13 +4,14 @@
 
 # standard Dash imports for callbacks (interactivity)
 from dash.dependencies import Input, Output
-from dash.exceptions import PreventUpdate
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
 
 import crystal_toolkit.components as ctc
 
-app = dash.Dash()
+app = dash.Dash(
+    prevent_initial_callbacks=True,  # don't run callbacks on page load
+)
 
 # now we give a list of structures to pick from
 structures = [
@@ -30,16 +31,13 @@
 
 ctc.register_crystal_toolkit(app=app, layout=my_layout)
 
+
 # for the interactivity, we use a standard Dash callback
 @app.callback(
     Output(structure_component.id(), "data"),
     [Input("change_structure_button", "n_clicks")],
 )
 def update_structure(n_clicks):
-    # on load, n_clicks will be None, and no update is required
-    # after clicking on the button, n_clicks will be an int and incremented
-    if not n_clicks:
-        raise PreventUpdate
     return structures[n_clicks % 2]