Published
Edited
Aug 9, 2021
5 stars
{
const d3SvgNode = d3.select(svg`<svg width=${width} height=400></svg>`);
const sourceData = {
x: width / 2 - 100,
y: 200
};
const midData = {
x: width / 2 + 200,
y: 300
};
const targetData = {
x: width / 2 + 100,
y: 50
};
const drag = d3.drag().on("drag", dragged);
const link = d3SvgNode
.append("path")
.attr("d", diagonal(sourceData, targetData, midData))
.attr("fill", "none")
.attr("stroke", "steelblue");
const source = d3SvgNode
.append("circle")
.datum(sourceData)
.attr("r", 10)
.attr("cx", sourceData.x)
.attr("cy", sourceData.y)
.attr("fill", "steelblue")
.attr("cursor", "move")
.call(drag);
const target = d3SvgNode
.append("circle")
.datum(targetData)
.attr("r", 10)
.attr("cx", targetData.x)
.attr("cy", targetData.y)
.attr("fill", "steelblue")
.attr("cursor", "move")
.call(drag);
const mid = d3SvgNode
.append("circle")
.datum(midData)
.attr("r", 10)
.attr("cx", midData.x)
.attr("cy", midData.y)
.attr("fill", "steelblue")
.attr("cursor", "move")
.call(drag);
function dragged(d) {
d.x = d3.event.x;
d.y = d3.event.y;
update();
}
function update() {
source.attr("cx", sourceData.x).attr("cy", sourceData.y);
target.attr("cx", targetData.x).attr("cy", targetData.y);
mid.attr("cx", midData.x).attr("cy", midData.y);
link.attr("d", diagonal(sourceData, targetData, midData));
}
yield d3SvgNode.node();
}
function diagonal(s, t, m) {
const x = s.x;
const y = s.y;
const ex = t.x;
const ey = t.y;
let mx = m?.x ?? x;
let my = m?.y ?? y;
let xrvs = ex - x < 0 ? -1 : 1;
let yrvs = ey - y < 0 ? -1 : 1;
let rdef = 35;
let r = Math.abs(ex - x) / 2 < rdef ? Math.abs(ex - x) / 2 : rdef;
r = Math.abs(ey - y) / 2 < r ? Math.abs(ey - y) / 2 : r;
let h = Math.abs(ey - y) / 2 - r;
let w = Math.abs(ex - x) - r * 2;
//w=0;
const path = `
M ${mx} ${my}
L ${x} ${my}
L ${x} ${y}
L ${x} ${y + h * yrvs}
C ${x} ${y + h * yrvs + r * yrvs} ${x} ${
y + h * yrvs + r * yrvs
} ${x + r * xrvs} ${y + h * yrvs + r * yrvs}
L ${x + w * xrvs + r * xrvs} ${y + h * yrvs + r * yrvs}
C ${ex} ${y + h * yrvs + r * yrvs} ${ex} ${
y + h * yrvs + r * yrvs
} ${ex} ${ey - h * yrvs}
L ${ex} ${ey}
`;
return path;
}
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.