chart = {
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [-width / 2, -height / 2, width, height]);
const simulation = d3.forceSimulation()
.force("charge", d3.forceManyBody().strength(-1000))
.force("link", d3.forceLink().id(d => d.id).distance(200))
.force("x", d3.forceX())
.force("y", d3.forceY())
.on("tick", ticked);
let link = svg.append("g")
.attr("stroke", "#000")
.attr("stroke-width", 1.5)
.selectAll("line");
let node = svg.append("g")
.attr("stroke", "#fff")
.attr("stroke-width", 1.5)
.selectAll("circle");
function ticked() {
node.attr("cx", d => d.x)
.attr("cy", d => d.y)
link.attr("x1", d => d.source.x)
.attr("y1", d => d.source.y)
.attr("x2", d => d.target.x)
.attr("y2", d => d.target.y);
}
invalidation.then(() => simulation.stop());
return Object.assign(svg.node(), {
update({nodes, links}) {
const old = new Map(node.data().map(d => [d.id, d]));
nodes = nodes.map(d => Object.assign(old.get(d.id) || {}, d));
links = links.map(d => Object.assign({}, d));
simulation.nodes(nodes);
simulation.force("link").links(links);
simulation.alpha(1).restart();
node = node
.data(nodes, d => d.id)
.join(enter => enter.append("circle")
.attr("r", 8)
.attr("fill", d => color(d.id)));
link = link
.data(links, d => `${d.source.id}\t${d.target.id}`)
.join("line");
}
});
}