| license: mit |
Faking a multi-rooted tree by using CSS to hide the root element. A more complete solution might have the animation of each branch starting at the first visible node, but this is a reasonable first pass.
For Stack Overflow question collapsible graph in d3: multiple root points
| <!DOCTYPE html> | |
| <html lang="en"> | |
| <head> | |
| <meta charset="utf-8"> | |
| <title>Tree Example</title> | |
| <style> | |
| .node { | |
| cursor: pointer; | |
| } | |
| .node circle { | |
| fill: #fff; | |
| stroke: steelblue; | |
| stroke-width: 3px; | |
| } | |
| .node text { | |
| font: 12px sans-serif; | |
| } | |
| .link { | |
| fill: none; | |
| stroke: #ccc; | |
| stroke-width: 2px; | |
| } | |
| .level-0 { | |
| opacity: 0; | |
| } | |
| </style> | |
| </head> | |
| <body> | |
| <!-- load the d3.js library --> | |
| <script src="http://d3js.org/d3.v3.min.js"></script> | |
| <script> | |
| var treeData = [{ | |
| name: "null", | |
| children: [{ | |
| "name": "Top Level_1", | |
| "parent": "null", | |
| "children": [{ | |
| "name": "Level 2: A", | |
| "parent": "Top Level_1", | |
| "children": [{ | |
| "name": "Son of A", | |
| "parent": "Level 2: A" | |
| }, { | |
| "name": "Daughter of A", | |
| "parent": "Level 2: A" | |
| }] | |
| }, | |
| { | |
| "name": "Level 2: B", | |
| "parent": "Top Level" | |
| }], | |
| }, { | |
| "name": "Top Level_2", | |
| "parent": "null", | |
| "children": [ | |
| { | |
| "name": "Level 2_2: A", | |
| "parent": "Top Level_2", | |
| "children": [ | |
| { | |
| "name": "Son of A_2", | |
| "parent": "Level 2_2: A" | |
| }, | |
| { | |
| "name": "Daughter of A_2", | |
| "parent": "Level 2_2: A" | |
| }] | |
| }, | |
| { | |
| "name": "Level 2_2: B", | |
| "parent": "Top Level_2" | |
| }] | |
| }] | |
| }]; | |
| // ************** 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("body").append("svg") | |
| .attr("width", width + margin.right + margin.left) | |
| .attr("height", height + margin.top + margin.bottom) | |
| .append("g") | |
| .attr("transform", "translate(" + (margin.left - 0) + "," + margin.top + ")"); | |
| root = treeData[0]; | |
| root.x0 = height / 2; | |
| root.y0 = 0; | |
| update(root); | |
| d3.select(self.frameElement).style("height", "500px"); | |
| 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 * 120; | |
| }); | |
| // 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", function(d) { | |
| return 'node level-' + d.depth; | |
| }) | |
| .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 ? -13 : 13; | |
| }) | |
| .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", 10) | |
| .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", function(d) { | |
| return 'link level-' + d.source.depth | |
| }) | |
| .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> |
