将json数据动态加载到D3节点中

Load json data into D3 nodes dynamically

本文关键字：D3 节点 加载 json 数据 动态      更新时间：2023-09-26

我是javascript/d3新手。我正在尝试将servlet中的json数据解析到javascript页面，然后使用d3-forcelayout设计(http://bl.ocks.org/mbostock/950642)。

我能够读取放在我的项目中的json文件（在下面的星号中突出显示）。然而，我希望用户能够按下一个按钮来更新网络（从java中读取的数据），并直接从我的数据变量加载数据。因此，最初加载页面时不会显示任何网络。

注意：我在retrievedjson（）函数和document.getElementById（"demo"）中收到一个响应。innerHTML将我格式化的json粘贴到页面上。然而，我无法将我的数据变量加载到.nodes和.links中。有人能告诉我如何做到这一点吗？网页上显示的json片段显示在帖子的底部。

请参阅下面的相关HTML代码。

var xmlhttp = new XMLHttpRequest();
var data = "no data";
function loadjson(){
    xmlhttp.onreadystatechange=function() {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            retrievedjson(xmlhttp.responseText);
        }
    }
    xmlhttp.open("Get", "/nodenetwork/DemoServlet", true);
    xmlhttp.send();
}

function retrievedjson(response) {
    alert("got response");
    var json = JSON.parse(response);
    data = response;
    document.getElementById("demo").innerHTML = data;
}
var width = 960,
    height = 500
var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);
var force = d3.layout.force()
    .nodes(data.nodes)
    .links(data.links)
    .gravity(.05)
    .distance(100)
    .charge(-100)
    .size([width, height]);
    *** This works fine when not commented out ** <!--
    d3.json("json/data.json", function(error, json) {
  force
      .nodes(json.nodes)
      .links(json.links)
      .start();
   -->
  var link = svg.selectAll(".link")
      .data(json.links)
    .enter().append("line")
      .attr("class", "link");
  var node = svg.selectAll(".node")
      .data(json.nodes)
    .enter().append("g")
      .attr("class", "node")
      .call(force.drag);
  node.append("image")
      .attr("xlink:href", "https://github.com/favicon.ico")
      .attr("x", -8)
      .attr("y", -8)
      .attr("width", 16)
      .attr("height", 16);
  node.append("text")
      .attr("dx", 12)
      .attr("dy", ".35em")
      .text(function(d) { return d.sourceName });
  force.on("tick", function() {
    link.attr("x1", function(d) { return d.source.x; })
        .attr("y1", function(d) { return d.source.y; })
        .attr("x2", function(d) { return d.target.x; })
        .attr("y2", function(d) { return d.target.y; });
    node.attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });
  });
});

JSON片段：

{"nodes":[{"sourceName":"Citrix","targets":[]},{"sourceName":"Neon","targets":[]},{"sourceName":"Unknown","targets":[]},{"sourceName":"Clayton","targets":[{"targetSystem":"Citrix","interfaceData":"Frequent 3.4","teams":"H"}]}],
"links":[{"source": 1,"target": 0, "value": 1},{"source": 2,"target": 0, "value": 1},{"source": 2,"target": 1, "value": 1}]}

感谢：）

var xmlhttp = new XMLHttpRequest();
var data = "no data";
function loadjson(){
    xmlhttp.onreadystatechange=function() {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
            retrievedjson(xmlhttp.responseText);
        }
    }
    xmlhttp.open("Get", "/nodenetwork/DemoServlet", true);
    xmlhttp.send();
}
function retrievedjson(response) {
    alert("got response");
    var json = JSON.parse(response);
    data = response;
    document.getElementById("demo").innerHTML = data;
}
var width = 960,
    height = 500
var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);
var data = {"nodes":[{"sourceName":"Citrix","targets":[]},{"sourceName":"Neon","targets":[]},{"sourceName":"Unknown","targets":[]},{"sourceName":"Clayton","targets":[{"targetSystem":"Citrix","interfaceData":"Frequent 3.4","teams":"H"}]}],
"links":[{"source": 1,"target": 0, "value": 1},{"source": 2,"target": 0, "value": 1},{"source": 2,"target": 1, "value": 1}]};
var force = d3.layout.force()
    .nodes(data.nodes)
    .links(data.links)
    .gravity(.05)
    .distance(100)
    .charge(-100)
    .size([width, height]);
json = data;
    
    //d3.json("json/data.json", function(error, json) {
  force
      .nodes(json.nodes)
      .links(json.links)
      .start();
  var link = svg.selectAll(".link")
      .data(json.links)
    .enter().append("line")
      .attr("class", "link");
  var node = svg.selectAll(".node")
      .data(json.nodes)
    .enter().append("g")
      .attr("class", "node")
      .call(force.drag);
  node.append("image")
      .attr("xlink:href", "https://github.com/favicon.ico")
      .attr("x", -8)
      .attr("y", -8)
      .attr("width", 16)
      .attr("height", 16);
  node.append("text")
      .attr("dx", 12)
      .attr("dy", ".35em")
      .text(function(d) { return d.sourceName });
  force.on("tick", function() {
    link.attr("x1", function(d) { return d.source.x; })
        .attr("y1", function(d) { return d.source.y; })
        .attr("x2", function(d) { return d.target.x; })
        .attr("y2", function(d) { return d.target.y; });
    node.attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });
  });
//});
.link {
  stroke: #ccc;
}
.node text {
  pointer-events: none;
  font: 10px sans-serif;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>

 var force = d3.layout.force()
    .nodes(data.nodes)
    .links(data.links)
    .gravity(.05)
    .distance(100)
    .charge(-100)
    .size([width, height]);
force.nodes(json.nodes)
      .links(json.links)
      .start();
  var link = svg.selectAll(".link")
      .data(json.links)
    .enter().append("line")
      .attr("class", "link");
  var node = svg.selectAll(".node")
      .data(json.nodes)
    .enter().append("g")
      .attr("class", "node")
      .call(force.drag);
  node.append("image")
      .attr("xlink:href", "https://github.com/favicon.ico")
      .attr("x", -8)
      .attr("y", -8)
      .attr("width", 16)
      .attr("height", 16);
  node.append("text")
      .attr("dx", 12)
      .attr("dy", ".35em")
      .text(function(d) { return d.sourceName });
  force.on("tick", function() {
    link.attr("x1", function(d) { return d.source.x; })
        .attr("y1", function(d) { return d.source.y; })
        .attr("x2", function(d) { return d.target.x; })
        .attr("y2", function(d) { return d.target.y; });
    node.attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; });
  });

把上面的代码放在一个函数中，将数据（响应）作为参数传递给这个函数，我认为这可能对你有用。。。如果没有，要求更多。

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