An example file to go alongside a question asked on Stack Overflow as to how to load a JSON array from an internal array rarther than import it as a file. The example here is a combination of Mike Bostocks Collapsible Tree example and a question asked on Stack Overflow on how to generate multi-level JSON formatted data.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Tree Example</title>
<style>
.bs-sidebar .nav > .active > ul {
display: block;
margin-bottom: 8px;
}
text.shadow {
stroke: white;
stroke-width: 2.3px;
opacity: 0.5;
}
.node {
cursor: pointer;
}
.node circle {
fill: #fff;
stroke: steelblue;
stroke-width: 1.5px;
}
.node text {
font: 10px sans-serif;
}
.link {
fill: none;
stroke: #ccc;
stroke-width: 1.5px;
}
</style>
</head>
<body>
<!-- load the d3.js library -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.17/d3.min.js"></script>
<div id="area1"></div>
<div id="area2"></div>
<script>
var data = [
{ "name" : "ABC", "parent":"DEF", "relation": "ghi", "depth": 1 },
{ "name" : "DEF", "parent":"null", "relation": "null", "depth": 0 },
{ "name" : "new_name", "parent":"ABC", "relation": "rel", "depth": 2 },
{ "name" : "new_name2", "parent":"ABC", "relation": "foo", "depth": 2 },
{ "name" : "Foo", "parent":"DEF", "relation": "rel", "depth": 2 }
];
// *********** Convert flat data into a nice tree ***************
// create a name: node map
var dataMap = data.reduce(function(map, node) {
map[node.name] = node;
return map;
}, {});
// create the tree array
var treeData = [];
data.forEach(function(node) {
// add to parent
var parent = dataMap[node.parent];
if (parent) {
// create child array if it doesn't exist
(parent.children || (parent.children = []))
// add node to child array
.push(node);
} else {
// parent is null or missing
treeData.push(node);
}
});
// show what we've got
d3.select('#area1').append('pre')
.text(JSON.stringify(treeData, null, ' '));
// ************** Generate the tree diagram *****************
var margin = {top: 20, right: 120, bottom: 20, left: 120},
width = 960 - margin.right - margin.left,
height = 500 - margin.top - margin.bottom;
var i = 0,
duration = 750,
root;
var tree = d3.layout.tree()
.size([height, width]);
var diagonal = d3.svg.diagonal()
.projection(function(d) { return [d.y, d.x]; });
var svg = d3.select("#area2").append("svg")
.attr("width", width + margin.right + margin.left)
.attr("height", height + margin.top + margin.bottom)
.append("g")
.attr("transform", "translate(" + margin.left + "," + margin.top + ")");
d3.json("example.json", function(error, DEF) {
root = DEF;
root.x0 = height / 2;
root.y0 = 0;
function collapse(d) {
if (d.children) {
d._children = d.children;
d._children.forEach(collapse);
d.children = null;
}
}
root.children.forEach(collapse);
update(root);
});
d3.select(self.frameElement).style("height", "800px");
function update(source) {
// Compute the new tree layout.
var nodes = tree.nodes(root).reverse(),
links = tree.links(nodes);
// Normalize for fixed-depth.
nodes.forEach(function(d) { d.y = d.depth * 180; });
// Update the nodes…
var node = svg.selectAll("g.node")
.data(nodes, function(d) { return d.id || (d.id = ++i); });
// Enter any new nodes at the parent's previous position.
var nodeEnter = node.enter().append("g")
.attr("class", "node")
.attr("transform", function(d) { return "translate(" + source.y0 + "," + source.x0 + ")"; })
.on("click", click);
nodeEnter.append("circle")
.attr("r", 1e-6)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeEnter.append("text")
.attr("x", function(d) { return d.children || d._children ? -10 : 10; })
.attr("dy", ".35em")
.attr("text-anchor", function(d) { return d.children || d._children ? "end" : "start"; })
.text(function(d) { return d.name; })
.style("fill-opacity", 1e-6);
// Transition nodes to their new position.
var nodeUpdate = node.transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + d.y + "," + d.x + ")"; });
nodeUpdate.select("circle")
.attr("r", 4.5)
.style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });
nodeUpdate.select("text")
.style("fill-opacity", 1);
// Transition exiting nodes to the parent's new position.
var nodeExit = node.exit().transition()
.duration(duration)
.attr("transform", function(d) { return "translate(" + source.y + "," + source.x + ")"; })
.remove();
nodeExit.select("circle")
.attr("r", 1e-6);
nodeExit.select("text")
.style("fill-opacity", 1e-6);
// Update the links…
var link = svg.selectAll("path.link")
.data(links, function(d) { return d.target.id; });
// Enter any new links at the parent's previous position.
link.enter().insert("path", "g")
.attr("class", "link")
.attr("d", function(d) {
var o = {x: source.x0, y: source.y0};
return diagonal({source: o, target: o});
});
// Transition links to their new position.
link.transition()
.duration(duration)
.attr("d", diagonal);
// Transition exiting nodes to the parent's new position.
link.exit().transition()
.duration(duration)
.attr("d", function(d) {
var o = {x: source.x, y: source.y};
return diagonal({source: o, target: o});
})
.remove();
// Stash the old positions for transition.
nodes.forEach(function(d) {
d.x0 = d.x;
d.y0 = d.y;
});
}
// Toggle children on click.
function click(d) {
if (d.children) {
d._children = d.children;
d.children = null;
} else {
d.children = d._children;
d._children = null;
}
update(d);
}
</script>
</body>
</html>
{
"name": "DEF",
"parent": "null",
"relation": "null",
"depth": 0,
"children": [
{
"name": "ABC",
"parent": "DEF",
"relation": "ghi",
"depth": 1,
"children": [
{
"name": "new_name",
"parent": "ABC",
"relation": "rel",
"depth": 2
},
{
"name": "new_name2",
"parent": "ABC",
"relation": "foo",
"depth": 2
}
]
},
{
"name": "Foo",
"parent": "DEF",
"relation": "rel",
"depth": 2
}
]
}