This is a d3.js tree diagram that incldes an interactive element as used as an example in the book D3 Tips and Tricks v4.x.
Any parent node can be clicked on to collapse the portion of the tree below it, on itself. Conversly, it can be clicked on again to regrow.
It is derived from the Mike Bostock Collapsible tree example and updated to use v4.
Kudos and thanks also go out to Soumya Ranjan for steering me in the fight direction for the diagonal solution.
| <!DOCTYPE html> | |
| <meta charset="UTF-8"> | |
| <style> | |
| .node circle { | |
| fill: #fff; | |
| stroke: steelblue; | |
| stroke-width: 3px; | |
| } | |
| .node text { | |
| font: 12px sans-serif; | |
| } | |
| .link { | |
| fill: none; | |
| stroke: #ccc; | |
| stroke-width: 2px; | |
| } | |
| </style> | |
| <body> | |
| <!-- load the d3.js library --> | |
| <script src="https://d3js.org/d3.v4.min.js"></script> | |
| <script> | |
| var treeData = | |
| { | |
| "name": "Top Level", | |
| "children": [ | |
| { | |
| "name": "Level 2: A", | |
| "children": [ | |
| { "name": "Son of A" }, | |
| { "name": "Daughter of A" } | |
| ] | |
| }, | |
| { "name": "Level 2: B" } | |
| ] | |
| }; | |
| // Set the dimensions and margins of the diagram | |
| var margin = {top: 20, right: 90, bottom: 30, left: 90}, | |
| width = 960 - margin.left - margin.right, | |
| height = 500 - margin.top - margin.bottom; | |
| // 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.right + margin.left) | |
| .attr("height", height + margin.top + margin.bottom) | |
| .append("g") | |
| .attr("transform", "translate(" | |
| + margin.left + "," + margin.top + ")"); | |
| var i = 0, | |
| duration = 750, | |
| root; | |
| // declares a tree layout and assigns the size | |
| var treemap = d3.tree().size([height, width]); | |
| // Assigns parent, children, height, depth | |
| root = d3.hierarchy(treeData, function(d) { return d.children; }); | |
| root.x0 = height / 2; | |
| root.y0 = 0; | |
| // Collapse after the second level | |
| root.children.forEach(collapse); | |
| 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 = treemap(root); | |
| // Compute the new tree layout. | |
| var nodes = treeData.descendants(), | |
| links = treeData.descendants().slice(1); | |
| // Normalize for fixed-depth. | |
| nodes.forEach(function(d){ d.y = d.depth * 180}); | |
| // ****************** Nodes section *************************** | |
| // Update the nodes... | |
| var node = svg.selectAll('g.node') | |
| .data(nodes, function(d) {return 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.y0 + "," + source.x0 + ")"; | |
| }) | |
| .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("dy", ".35em") | |
| .attr("x", function(d) { | |
| return d.children || d._children ? -13 : 13; | |
| }) | |
| .attr("text-anchor", function(d) { | |
| return d.children || d._children ? "end" : "start"; | |
| }) | |
| .text(function(d) { return d.data.name; }); | |
| // UPDATE | |
| var nodeUpdate = nodeEnter.merge(node); | |
| // Transition to the proper position for the node | |
| nodeUpdate.transition() | |
| .duration(duration) | |
| .attr("transform", function(d) { | |
| return "translate(" + d.y + "," + d.x + ")"; | |
| }); | |
| // Update the node attributes and style | |
| nodeUpdate.select('circle.node') | |
| .attr('r', 10) | |
| .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(d) { | |
| return "translate(" + source.y + "," + source.x + ")"; | |
| }) | |
| .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 = svg.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); | |
| // 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(d) { | |
| 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) { | |
| path = `M ${s.y} ${s.x} | |
| C ${(s.y + d.y) / 2} ${s.x}, | |
| ${(s.y + d.y) / 2} ${d.x}, | |
| ${d.y} ${d.x}` | |
| return path | |
| } | |
| // 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> |
