Marker the multi-directional edges and self-loop edges in d3

[QB]

Hi all,

I have been trying to modify GerHobbelt's code for collapsing/expanding nodes (http://bl.ocks.org/GerHobbelt/3071239) to add node's label and direction of the edges. However, I haven't managed to show the marker at the end of an edge if the edge is multidirectional. For some reason, it only shows one direction and ignored another. In addition, the self-loop edge only shows its marker without the edge.

So, can someone assist me with my problems above?

I also posted the code I've worked so far in https://stackoverflow.com/questions/66122975/marker-the-multi-directional-edges-and-self-loop-edges-in-d3

Thanks everyone for any suggestion