const svg = d3.select('#mySVG')
const nodesG = svg.select("g.nodes")
var graphs = {
"nodes": [{
"name": "Peter",
"label": "Person",
"id": 1
},
{
"name": "Michael",
"label": "Person",
"id": 2
},
{
"name": "Neo4j",
"label": "Database",
"id": 3
},
{
"name": "Graph Database",
"label": "Database",
"id": 4
}
],
"links": [{
"source": 1,
"target": 2,
"type": "KNOWS",
"since": 2010
},
{
"source": 1,
"target": 3,
"type": "FOUNDED"
},
{
"source": 2,
"target": 3,
"type": "WORKS_ON"
},
{
"source": 3,
"target": 4,
"type": "IS_A"
}
]
}
svg.append('defs').append('marker')
.attr('id', 'arrowhead')
.attr('viewBox', '-0 -5 10 10')
.attr('refX', 0)
.attr('refY', 0)
.attr('orient', 'auto')
.attr('markerWidth', 13)
.attr('markerHeight', 13)
.attr('xoverflow', 'visible')
.append('svg:path')
.attr('d', 'M 0,-5 L 10 ,0 L 0,5')
.attr('fill', '#999')
.style('stroke', 'none');
const simulation = d3.forceSimulation()
.force("link", d3.forceLink().id(d => d.id))
.force("charge", d3.forceManyBody())
.force("center", d3.forceCenter(100, 100));
let linksData = graphs.links.map(link => {
var obj = link;
obj.source = link.source;
obj.target = link.target;
return obj;
})
const links = svg.select("g.links")
.selectAll("path")
.data(linksData)
.enter()
.append("path")
.attr('stroke', '#666666')
.attr('fill', 'transparent')
.attr("stroke-width", 2)
.attr('marker-end', 'url(#arrowhead)')
const nodes = nodesG
.selectAll("g")
.data(graphs.nodes)
.enter().append("g")
.attr("cursor", "pointer")
.call(d3.drag()
.on("start", dragstarted)
.on("drag", dragged)
.on("end", dragended));
const circles = nodes.append("circle")
.attr("r", 12)
.attr("fill", "000000")
nodes.append("title")
.text(function(d) {
return d.id;
});
simulation
.nodes(graphs.nodes)
.on("tick", ticked);
simulation.force("link", d3.forceLink().links(linksData)
.id((d, i) => d.id)
.distance(150));
function ticked() {
links.attr("d", function(d) {
var dx = (d.target.x - d.source.x),
dy = (d.target.y - d.source.y),
dr = Math.sqrt(dx * dx + dy * dy);
return "M" + d.source.x + "," + d.source.y + "A" + dr + "," + dr + " 0 0,1 " + d.target.x + "," + d.target.y;
});
// recalculate and back off the distance
links.attr("d", function(d) {
// length of current path
var pl = this.getTotalLength(),
// radius of circle plus backoff
r = (12) + 30,
// position close to where path intercepts circle
m = this.getPointAtLength(pl - r);
var dx = m.x - d.source.x,
dy = m.y - d.source.y,
dr = Math.sqrt(dx * dx + dy * dy);
return "M" + d.source.x + "," + d.source.y + "A" + dr + "," + dr + " 0 0,1 " + m.x + "," + m.y;
});
nodes
.attr("transform", d => `translate(${d.x}, ${d.y})`);
}
function dragstarted(d) {
if (!d3.event.active) simulation.alphaTarget(0.3).restart();
d.fx = d.x;
d.fy = d.y;
}
function dragged(d) {
d.fx = d3.event.x;
d.fy = d3.event.y;
}
function dragended(d) {
if (!d3.event.active) simulation.alphaTarget(0);
d.fx = null;
d.fy = null;
}
<html lang="en">
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<script src="//d3js.org/d3.v4.min.js" type="text/javascript"></script>
</head>
<body>
<svg id="mySVG" width="500" height="500">
<g class="links" />
<g class="nodes" />
</svg>