Component only updated by dash callbacks when we click them

[xhluca]

In demo page's SourceViewer demo, we can see that the component is updated every time the slider is dragged:

However, the same demo in Dash doesn't automatically update the component when the callback is fired by the slider; instead, you have to click on the canvas:

Any idea why this might happen?

[jourdain]

Yes we need to trigger a render. I've already done the change earlier this morning on the react library. But I will need the update code to change another state on the view.

[xhluca]

Sure! Which update code would it be?

[jourdain]

I was retrying to do that,

@app.callback(
    Output("vtk-view", "triggerRender"),
    [],
)
def render():
    render_count += 1
    return render_count


@app.callback(
    Output("vtk-algorithm", "state"),
    [Input("slider-resolution", "value"), Input("capping-checklist", "value")],
)
def update_cone(slider_val, checked_values):
    render()
    return {"resolution": slider_val, "capping": "capping" in checked_values}

[xhluca]

def render():
    render_count += 1
    return render_count


@app.callback(
    [Output("vtk-algorithm", "state"), Output("vtk-view", "triggerRender")],
    [Input("slider-resolution", "value"), Input("capping-checklist", "value")],
)
def update_cone(slider_val, checked_values):
    render()
    return [ {"resolution": slider_val, "capping": "capping" in checked_values}, update]

[xhluca]

@app.callback(
  Output(...),
  [Input('my-slider'...)],
  [State('graph', 'data')]
)
def update_cone(slider_value, my_data):
  ...
  return ...

If graph is updated, the callback will be triggered. but if slider is updated, callback will be triggered.

[xhluca]

@jourdain Just sharing in case you are not aware: I tried running usage-pyvista-terrain-following-mesh and the triggerRender doesn't seem to work.

[jourdain]

need to re-run npm i

[xhluca]

Ok it works. thanks!