Published
Edited
Apr 5, 2022
2 forks
2 stars
function ForceGraph({
nodes,
links
}, {
nodeId = d => d.id,
nodeGroup,
nodeGroups,
nodeTitle,
nodeFill = "currentColor",
nodeStroke = "#fff",
nodeStrokeWidth = 1.5,
nodeStrokeOpacity = 1,
nodeRadius = 5,
nodeStrength,
linkSource = ({source}) => source,
linkTarget = ({target}) => target,
linkStroke = "#999",
linkStrokeOpacity = 0.6,
linkStrokeWidth = 1.5,
linkStrokeLinecap = "round",
linkStrength,
colors = d3.schemeTableau10,
width = 640,
height = 400,
invalidation
} = {}) {
// Compute values.
const N = d3.map(nodes, nodeId).map(intern);
const LS = d3.map(links, linkSource).map(intern);
const LT = d3.map(links, linkTarget).map(intern);
if (nodeTitle === undefined) nodeTitle = (_, i) => N[i];
const T = nodeTitle == null ? null : d3.map(nodes, nodeTitle);
const G = nodeGroup == null ? null : d3.map(nodes, nodeGroup).map(intern);
const W = typeof linkStrokeWidth !== "function" ? null : d3.map(links, linkStrokeWidth);
const L = typeof linkStroke !== "function" ? null : d3.map(links, linkStroke);
// Replace the input nodes and links with mutable objects for the simulation.
nodes = d3.map(nodes, (_, i) => ({id: N[i]}));
links = d3.map(links, (_, i) => ({source: LS[i], target: LT[i]}));
// Compute default domains.
if (G && nodeGroups === undefined) nodeGroups = d3.sort(G);
// Construct the scales.
const color = nodeGroup == null ? null : d3.scaleOrdinal(nodeGroups, colors);
// Construct the forces.
const forceNode = d3.forceManyBody();
const forceLink = d3.forceLink(links).id(({index: i}) => N[i]);
if (nodeStrength !== undefined) forceNode.strength(nodeStrength);
if (linkStrength !== undefined) forceLink.strength(linkStrength);
const simulation = d3.forceSimulation(nodes)
.force("link", forceLink)
.force("charge", forceNode)
.force("center", d3.forceCenter())
.on("tick", ticked);
const svg = d3.create("svg")
.attr("width", width)
.attr("height", height)
.attr("viewBox", [-width / 2, -height / 2, width, height])
.attr("style", "max-width: 100%; height: auto; height: intrinsic;");
const link = svg.append("g")
.attr("stroke", typeof linkStroke !== "function" ? linkStroke : null)
.attr("stroke-opacity", linkStrokeOpacity)
.attr("stroke-width", typeof linkStrokeWidth !== "function" ? linkStrokeWidth : null)
.attr("stroke-linecap", linkStrokeLinecap)
.selectAll("line")
.data(links)
.join("line");
const node = svg.append("g")
.attr("fill", nodeFill)
.attr("stroke", nodeStroke)
.attr("stroke-opacity", nodeStrokeOpacity)
.attr("stroke-width", nodeStrokeWidth)
.selectAll("circle")
.data(nodes)
.join("circle")
.attr("r", nodeRadius)
.call(drag(simulation));
if (W) link.attr("stroke-width", ({index: i}) => W[i]);
if (L) link.attr("stroke", ({index: i}) => L[i]);
if (G) node.attr("fill", ({index: i}) => color(G[i]));
if (T) node.append("title").text(({index: i}) => T[i]);
if (invalidation != null) invalidation.then(() => simulation.stop());
function intern(value) {
return value !== null && typeof value === "object" ? value.valueOf() : value;
}
function ticked() {
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);
node
.attr("cx", d => d.x)
.attr("cy", d => d.y);
}
function drag(simulation) {
function dragstarted(event) {
if (!event.active) simulation.alphaTarget(0.3).restart();
event.subject.fx = event.subject.x;
event.subject.fy = event.subject.y;
}
function dragged(event) {
event.subject.fx = event.x;
event.subject.fy = event.y;
}
function dragended(event) {
if (!event.active) simulation.alphaTarget(0);
event.subject.fx = null;
event.subject.fy = null;
}
return d3.drag()
.on("start", dragstarted)
.on("drag", dragged)
.on("end", dragended);
}
return Object.assign(svg.node(), {scales: {color}});
}
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