d3 network (graph) visualization - remove node (+ links) on click

Question

I've been trying to adjust the following code: https://bl.ocks.org/mbostock/4062045 in such a way to make it possible to remove the node + its links on mouse-click.

What I tried so far was adding the following code:

.on("click",function() {
            d3.select(this).remove();
            restart();
            })

And this snippet from here: https://bl.ocks.org/mbostock/1095795

function restart() {

  // Apply the general update pattern to the nodes.
  node = node.data(nodes, function(d) { return d.id;});
  node.exit().remove();
  node = node.enter().append("circle").attr("fill", function(d) { return color(d.id); }).attr("r", 8).merge(node);

  // Apply the general update pattern to the links.
  link = link.data(links, function(d) { return d.source.id + "-" + d.target.id; });
  link.exit().remove();
  link = link.enter().append("line").merge(link);

  // Update and restart the simulation.
  simulation.nodes(nodes);
  simulation.force("link").links(links);
  simulation.alpha(1).restart();
}

If I first specify nodes and links the following way:

  var nodes = [{id: "Simplice"},{id: "Valjean"}]
  var links = [{"source": "Simplice", "target": "Valjean", "value": 3}]

restart(); removes all nodes and links except the specified ones - I am trying to achieve the opposite. Therefore, I am able to remove all elements except ones specified and the graph redraws itself nicely, but I am not able to make it remove selected nodes.

d3.select(this).remove(); removes the node but not the links and does not redraw the graph.

My idea is to: 1. store the json data in "nodes" variable. 2. Remove the element and its links from "nodes" variable on mouse-click.

Then the graph should redraw itself nicely. Any ideas how to do it?

Answer 1

Rather than modifying the document with d3.select(this).remove(), you need to modify the data itself (i.e. nodes and links instead of node and link). I think this is basically what you are describing at the end of your question.

For example, try something like this:

.on("click", function(d){
    nodes = nodes.filter(function(n){ return n.id !== d.id; });
    links = links.filter(function(e){
      return e.source.id !== d.id && e.target.id !== d.id;
    });
    restart();
});