| license: mit |
This is a tree diagram that loads the data for the tree from an external JSON file. It was written with d3.js v4 and is based on the simple horizontal version here
This is designed to be used as part of documenting an update to the book D3 Tips and Tricks to version 4 of d3.js.
forked from d3noob's block: Tree diagram loading external json with v4
| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <style> /* set the CSS */ | |
| .node circle { | |
| fill: #fff; | |
| stroke: steelblue; | |
| stroke-width: 3px; | |
| } | |
| .node text { font: 12px sans-serif; } | |
| .node--internal text { | |
| text-shadow: 0 1px 0 #fff, 0 -1px 0 #fff, 1px 0 0 #fff, -1px 0 0 #fff; | |
| } | |
| .link { | |
| fill: none; | |
| stroke: #ccc; | |
| stroke-width: 2px; | |
| } | |
| </style> | |
| <body> | |
| <!-- load the d3.js library --> | |
| <script src="//d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| // set the dimensions and margins of the diagram | |
| var margin = {top: 20, right: 90, bottom: 30, left: 90}, | |
| width = 660 - margin.left - margin.right, | |
| height = 500 - margin.top - margin.bottom; | |
| // declares a tree layout and assigns the size | |
| var treemap = d3.tree() | |
| .size([height, width]); | |
| // load the external data | |
| d3.json("treeData.json", function(error, treeData) { | |
| if (error) throw error; | |
| // assigns the data to a hierarchy using parent-child relationships | |
| var nodes = d3.hierarchy(treeData, function(d) { | |
| return d.children; | |
| }); | |
| // maps the node data to the tree layout | |
| nodes = treemap(nodes); | |
| // append the svg object to the body of the page | |
| // appends a 'group' element to 'svg' | |
| // moves the 'group' element to the top left margin | |
| var svg = d3.select("body").append("svg") | |
| .attr("width", width + margin.left + margin.right) | |
| .attr("height", height + margin.top + margin.bottom), | |
| g = svg.append("g") | |
| .attr("transform", | |
| "translate(" + margin.left + "," + margin.top + ")"); | |
| // adds the links between the nodes | |
| var link = g.selectAll(".link") | |
| .data( nodes.descendants().slice(1)) | |
| .enter().append("path") | |
| .attr("class", "link") | |
| .attr("d", function(d) { | |
| return "M" + d.y + "," + d.x | |
| + "C" + (d.y + d.parent.y) / 2 + "," + d.x | |
| + " " + (d.y + d.parent.y) / 2 + "," + d.parent.x | |
| + " " + d.parent.y + "," + d.parent.x; | |
| }); | |
| // adds each node as a group | |
| var node = g.selectAll(".node") | |
| .data(nodes.descendants()) | |
| .enter().append("g") | |
| .attr("class", function(d) { | |
| return "node" + | |
| (d.children ? " node--internal" : " node--leaf"); }) | |
| .attr("transform", function(d) { | |
| return "translate(" + d.y + "," + d.x + ")"; }); | |
| // adds the circle to the node | |
| node.append("circle") | |
| .attr("r", 10); | |
| // adds the text to the node | |
| node.append("text") | |
| .attr("dy", ".35em") | |
| .attr("x", function(d) { return d.children ? -13 : 13; }) | |
| .style("text-anchor", function(d) { | |
| return d.children ? "end" : "start"; }) | |
| .text(function(d) { return d.data.name; }); | |
| }); | |
| </script> | |
| </body> |
| { | |
| "name": "Top Level", | |
| "children": [ | |
| { | |
| "name": "Level 2: A", | |
| "children": [ | |
| { "name": "Son of A" }, | |
| { "name": "Daughter of A" } | |
| ] | |
| }, | |
| { "name": "Level 2: B" } | |
| ] | |
| } |