javascript - D3.js 可折叠树 : Adding a label for each level

Question

我正在开发一个项目，该项目需要为 D3.js 中可折叠树的每个级别添加一个标签(https://bl.ocks.org/mbostock/4339083)。我在添加相同内容时面临困难时期。我需要的标签已添加到随附的屏幕截图中。单击每个级别后，标签应立即为每个级别填充，并在树回滚时消失。谁能帮我解决这个问题。

Answer 1

修改更新方法以跟踪节点项的级别。维护来自用于绘制图表的节点项的所有深度值的唯一排序哈希。获得排序后的 depthHash 数组后，将文本绘制在图表顶部。以下是我修改过的 fiddle 供您引用。 http://jsfiddle.net/deepakpster/vomxqxov/3/

var margin = {top: 20, right: 120, bottom: 20, left: 120},
    width = 960 - margin.right - margin.left,
    height = 800 - 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 + "," + margin.top + ")");

flare = "http://rawgit.com/mbostock/1093025/raw/a05a94858375bd0ae023f6950a2b13fac5127637/flare.json"
d3.json(flare, function(error, flare) {
  root = flare;
  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; });
    // Showing the labels for the level of depths.
    // Using underscore.js to do the pluck, uniq.
  var depthHash = _.uniq(_.pluck(nodes, "depth")).sort();
  svg.selectAll("g.levels-svg").remove();
  var levelSVG = svg.append("g").attr("class", "levels-svg");
    var levels =  levelSVG.selectAll("g.level");
  levels.data(depthHash)
    .enter().append("g")
    .attr("class", "level")
    .attr("transform", function(d) { return "translate(" + d*180 + "," + 10 + ")"; })
    .append("text")
    .text(function(d){
      return "level-" + d; 
    });

  // 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"; });
  */
  var ww = 30, hh = 20
  nodeEnter.append("rect")
    .attr("height", 1e-6)
    .attr("width", 1e-6)
    .attr("x", -ww/2)
    .attr("y", -hh/2)
    .attr("rx", 3)
    .attr("ry", 3)
    .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("rect")
    .attr("width", ww)
    .attr("height", hh)
    .style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });

  nodeUpdate.select("circle")
      .attr("r", 4.5)
      .style("fill", function(d) { return d._children ? "lightsteelblue" : "#fff"; });

  nodeUpdate.select("text")
      .attr("dx", -10)
      .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);
}