How to Check Node is Expand or Collapse in Apache Echarts Tree

Question

I want to check node is Expand or Collapse on click.

I checked click event but did not get any flag for Collapse or Expand

    chart.on('click', e => {
      // want to access here 
    })

Answer 1

chart.on('click', func(params) {})

The params provide access to the collapsed flag.

I didn't have any luck using this outside of the scope of chart.setOption().

Since it's inside, you need to add "this" as the context for access-

chart.on('click', func(params){}, this)

Read more here- https://echarts.apache.org/en/api.html#echartsInstance.on