{
var width = 960,
height = 500;
// append the svg object to the body of the page
const svg = d3.select(createSvg `<svg width=500 height=500></svg>`);
const g = svg
.attr("width", width)
.attr("height", height)
.append("g")
.attr('transform',`translate(${width/2},100)`)
const duration = 750;
let i = 0,
root = d3.hierarchy(treeData, function(d) {
return d.children;
});
// Collapse after second level
root.children.forEach(collapse);
root.x0 = 0;
root.y0 = 0;
const flexLayout = flextree.flextree();
update(root);
// Collapse the node and all it's children
function collapse(d) {
if (d.children) {
d._children = d.children
d._children.forEach(collapse)
d.children = null
}
}
function update(source) {
// Assigns the x and y position for the nodes
var treeData = flexLayout(root)
// Compute the new tree layout.
var nodes = treeData.descendants(),
links = treeData.descendants().slice(1);
// ****************** Nodes section ***************************
// Update the nodes...
var node = g.selectAll('g.node')
.data(nodes, d=> d.id || (d.id = ++i));
// Enter any new modes at the parent's previous position.
var nodeEnter = node.enter().append('g')
.attr('class', 'node')
.attr("transform", function(d) {
return "translate(" + source.x0 + "," + source.y0 + ")";
})
.on('click', click);
// Add Circle for the nodes
nodeEnter.append('circle')
.attr('class', 'node')
.attr('r', 1e-6)
.style("fill", function(d) {
return d._children ? "lightsteelblue" : "#fff";
});
// Add labels for the nodes
nodeEnter.append('text')
.attr('pointer-events', 'none')
.attr('dy', '0.35em')
.text(function(d) {
return d.data.name;
})
.attr('text-anchor', 'middle')
// UPDATE
var nodeUpdate = nodeEnter.merge(node)
.attr("fill", "#fff")
.attr("stroke", "steelblue")
.attr("stroke-width", "3px;")
.style('font', '12px sans-serif')
// Transition to the proper position for the node
nodeUpdate.transition()
.duration(duration)
.attr("transform", function(event, i, arr) {
const d = d3.select(this).datum();
return "translate(" + d.x + "," + d.y + ")";
});
// Update the node attributes and style
nodeUpdate.select('circle.node')
.attr('r', 20)
.style("fill", function(d) {
return d._children ? "lightsteelblue" : "#fff";
})
.attr('cursor', 'pointer');
// Remove any exiting nodes
var nodeExit = node.exit().transition()
.duration(duration)
.attr("transform", function(event, i, arr) {
const d = d3.select(this).datum();
return "translate(" + source.x + "," + source.y + ")";
})
.remove();
// On exit reduce the node circles size to 0
nodeExit.select('circle')
.attr('r', 1e-6);
// On exit reduce the opacity of text labels
nodeExit.select('text')
.style('fill-opacity', 1e-6)
// ****************** links section ***************************
// Update the links...
var link = g.selectAll('path.link')
.data(links, function(d) {
return d.id;
});
// Enter any new links at the parent's previous position.
var linkEnter = link.enter().insert('path', "g")
.attr("class", "link")
.attr('d', function(d) {
var o = {
x: source.x0,
y: source.y0
}
return diagonal(o, o)
});
// UPDATE
var linkUpdate = linkEnter.merge(link)
.attr("fill", "none")
.attr("stroke", "#ccc")
.attr("stroke-width", "2px")
// Transition back to the parent element position
linkUpdate.transition()
.duration(duration)
.attr('d', function(d) {
return diagonal(d, d.parent)
});
// Remove any exiting links
var linkExit = link.exit().transition()
.duration(duration)
.attr('d', function(event, i, arr) {
const d = d3.select(this).datum();
var o = {
x: source.x,
y: source.y
}
return diagonal(o, o)
})
.remove();
// Store the old positions for transition.
nodes.forEach(function(d) {
d.x0 = d.x;
d.y0 = d.y;
});
// Creates a curved (diagonal) path from parent to the child nodes
function diagonal(s, d) {
const path = `M ${s.x} ${s.y}
C ${(s.x + d.x) / 2} ${s.y},
${(s.x + d.x) / 2} ${d.y},
${d.x} ${d.y}`
return path
}
// Toggle children on click.
function click(event, d) {
if (d.children) {
d._children = d.children;
d.children = null;
} else {
d.children = d._children;
d._children = null;
}
update(d);
}
}
yield svg.node()
}
treeData = ({
"name": "A",
"size": [100,100],
"children": [
{
"name": "BA",
"size": [100,50],
"children": [
{ "name": "BAA","size": [100,50] },
{ "name": "BAB",
"size": [100,50],
"children": [
{ "name": "BABA","size": [100,50] },
{ "name": "BABB","size": [100,50] }
]
},
{ "name": "BAC","size": [200,50] },
]
},
{ "name": "BB",
"size": [100,75],
"children": [
{ "name": "BBA","size": [50,50] },
{ "name": "BBB","size": [50,50] }
]
}
]
})
d3 = require('d3@v6')
flextree = require("d3-flextree@v2")
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
