Answers can be found here :widget interactivity :
Answers can be found here :
widget interactivity :
https://carto.com/developers/airship/examples/#example-as-histogram-events
https://github.com/jahow/ol-airship-bridge
widget coloured bars :
https://github.com/CartoDB/airship/pull/425/commits/c4eb2a3797c89b1e6eb1c9848a1f2135c0c49916