Thanks for your suggestions. Unfortunately, I left out some important details in my OP and so I’m still trying things.
The Google Charts are generated in an iframe, which is where the selection handler is. It means the handler is not in the context of the widget/macro, so ‘this’ isn’t meaningful.
I can access ‘window.parent.$tw’ and I’ve seen code fragments that make it look like I should be able to do the following:
window.parent.$tw.rootWidget.dispatchEvent( { type:‘tm-navigate’, navigateTo: ‘Tiddler Name Here’ } );
Nothing happens.
I’ve tried a couple of other event properties too: setting ‘param’ the same as ‘navigateTo’, and setting ‘navigateFromTitle’ to the name of the tiddler hosting the macro call. Nothing for those either. Not even error messages in the console.
Thanks again for your help. Hoping you or anyone else might have some new ideas…