| license: mit |
This is a tree diagram that used data from a 'flat' format. It has been written with d3.js v5 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 5 of d3.js.
| <!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="https://d3js.org/d3.v5.min.js"></script> | |
| <script> | |
| // the flat data | |
| var flatData = [ | |
| {"name": "Top Level", "parent": null}, | |
| {"name": "Level 2: A", "parent": "Top Level" }, | |
| {"name": "Level 2: B", "parent": "Top Level" }, | |
| {"name": "Son of A", "parent": "Level 2: A" }, | |
| {"name": "Daughter of A", "parent": "Level 2: A" } | |
| ]; | |
| // convert the flat data into a hierarchy | |
| var treeData = d3.stratify() | |
| .id(function(d) { return d.name; }) | |
| .parentId(function(d) { return d.parent; }) | |
| (flatData); | |
| // assign the name to each node | |
| treeData.each(function(d) { | |
| d.name = d.id; | |
| }); | |
| // 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]); | |
| // 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> |
