我的CollapsibleTree搜索代码无法运行，请求排查故障原因

API 探路者

2026-8-15

问题排查：本地运行可折叠树搜索代码无内容显示

我模仿了一个可折叠树带搜索功能的代码，本地创建了index.html及相关JS文件放在同一文件夹，但页面完全没内容。试过改用在线CDN引入脚本，问题依旧，请问哪里出问题了？

<!DOCTYPE html>
<meta charset="utf-8">
<style>

.node {
  cursor: pointer;
}

.node circle {
  fill: #fff;
  stroke: steelblue;
  stroke-width: 1.5px;
}

.node text {
  font: 10px sans-serif;
}

.link {
  fill: none;
  stroke: #ccc;
  stroke-width: 1.5px;
}

.found {
  fill: #ff4136;
  stroke: #ff4136;
}

.search {
  float: left;
  font: 10px sans-serif;
  width: 30%;
}

ul.select2-results {
 max-height: 100px;
}

.select2-container,
.select2-drop,
.select2-search,
.select2-search input {
  font: 10px sans-serif;
}

#block_container {
  display: inline;
}

</style>
<body>
<script src="javascripts/d3.min.js"></script>
<script src="javascripts/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="stylesheets/select2.min.css"></link>
<script type="text/javascript" src="javascripts/select2.min.js"></script>

<!-- <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.13/d3.min.js"></script> -->
<!-- <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> -->
<!-- <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/select2/3.5.2/select2.min.css"></link> -->
<!-- <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/select2/3.5.2/select2.min.js"></script> -->

<div id="block_container">
   <div id="searchName"></div>
</div>

<script>

//===============================================
function select2DataCollectName(d) {
    if (d.children)
        d.children.forEach(select2DataCollectName);
    else if (d._children)
        d._children.forEach(select2DataCollectName);
    select2Data.push(d.name);
}

//===============================================
function searchTree(d) {
    if (d.children)
        d.children.forEach(searchTree);
    else if (d._children)
        d._children.forEach(searchTree);
    var searchFieldValue = eval(searchField);
    if (searchFieldValue && searchFieldValue.match(searchText)) {
            // Walk parent chain
            var ancestors = [];
            var parent = d;
            while (typeof(parent) !== "undefined") {
                ancestors.push(parent);
        //console.log(parent);
                parent.class = "found";
                parent = parent.parent;
            }
        //console.log(ancestors);
    }
}

//===============================================
function clearAll(d) {
    d.class = "";
    if (d.children)
        d.children.forEach(clearAll);
    else if (d._children)
        d._children.forEach(clearAll);
}

//===============================================
function collapse(d) {
    if (d.children) {
        d._children = d.children;
        d._children.forEach(collapse);
        d.children = null;
    }
}

//===============================================
function collapseAllNotFound(d) {
    if (d.children) {
        if (d.class !== "found") {
            d._children = d.children;
            d._children.forEach(collapseAllNotFound);
            d.children = null;
    } else
            d.children.forEach(collapseAllNotFound);
    }
}

//===============================================
function expandAll(d) {
    if (d._children) {
        d.children = d._children;
        d.children.forEach(expandAll);
        d._children = null;
    } else if (d.children)
        d.children.forEach(expandAll);
}

//===============================================
// Toggle children on click.
function toggle(d) {
  if (d.children) {
    d._children = d.children;
    d.children = null;
  } else {
    d.children = d._children;
    d._children = null;
  }
  clearAll(root);
  update(d);
  $("#searchName").select2("val", "");
}

//===============================================
$("#searchName").on("select2-selecting", function(e) {
    clearAll(root);
    expandAll(root);
    update(root);

    searchField = "d.name";
    searchText = e.object.text;
    searchTree(root);
    root.children.forEach(collapseAllNotFound);
    update(root);
})

//===============================================
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 + ")");

d3.json("flare.json", function(error, flare) {
  root = flare;
  root.x0 = height / 2;
  root.y0 = 0;

  select2Data = [];
  select2DataCollectName(root);
  select2DataObject = [];
  select2Data.sort(function(a, b) {
            if (a > b) return 1; // sort
            if (a < b) return -1;
            return 0;
        })
        .filter(function(item, i, ar) {
            return ar.indexOf(item) === i;
        }) // remove duplicate items
        .filter(function(item, i, ar) {
            select2DataObject.push({
                "id": i,
                "text": item
            });
        });
  $("#searchName").select2({
        data: select2DataObject,
        containerCssClass: "search"
  });

  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; });

  // 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", toggle);

  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 ? -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("circle")
      .attr("r", 4.5)
      .style("fill", function(d) {
            if (d.class === "found") {
                return "#ff4136"; //red
            } else if (d._children) {
                return "lightsteelblue";
            } else {
                return "#fff";
            }
        })
        .style("stroke", function(d) {
            if (d.class === "found") {
                return "#ff4136"; //red
            }
        });

  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", "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)
      .style("stroke", function(d) {
            if (d.target.class === "found") {
                return "#ff4136";
            }
        });

  // 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;
  });
}

</script>

</body>
</html>

问题原因及修复方案

缺失核心数据文件：代码通过d3.json("flare.json")加载树形结构数据，但你本地没有这个文件，这是页面无内容的核心原因。需要获取对应结构的flare.json文件，放在和index.html同一目录下。
脚本加载顺序与页面结构不规范：当前把样式表<link>标签放在了脚本之后，且没有<head>标签包裹样式。建议调整页面结构，将<style>和<link>标签移到<head>内，确保页面加载时优先加载样式。
重复定义函数：代码中重复定义了collapse函数，全局作用域和d3.json回调内各有一个，会导致全局函数被覆盖，影响逻辑。删除全局的collapse函数，保留回调内的版本即可。

未处理JSON加载错误：原代码没有处理d3.json的加载失败情况，建议在回调中添加错误判断，方便排查问题：

d3.json("flare.json", function(error, flare) {
  if (error) throw error; // 添加此行，加载失败时抛出错误
  // 后续逻辑...
});

本地跨域限制：直接用浏览器打开本地HTML文件（file://协议），可能因跨域限制无法加载本地flare.json。解决方法是用本地服务器运行，比如用Python执行python -m http.server，或Node.js的http-server工具，通过http://localhost访问页面。

内容的提问来源于stack exchange，提问作者Daniel