Question

当json键为其获取空值时，我想停止向树中添加分支。我在代码D3 js tree layout

中使用此功能

示例json strucutre：

data[
     { from_id : 1, c1 : 2, c2 : 3, c3 : null},
     { from_id : 2, c1 : 26, c2 : 23, c3 : 23}
     { from_id : 3, c1 : 27, c2 : 34, c3 : 565}
     { from_id : 4, c1 : 28, c2 : 35, c3 : null}
     { from_id : 5, c1 : 29, c2 : 36, c3 : 766}
]

＆＃13;

/* 
 * All D3 visuals run in a frame with the following elements/variables:
 * 
 * SVG element: 
 * - <svg xmlns="http://www.w3.org/2000/svg" class="chart" id="chart" >
 * 
 * pbi object:
 * - 'dsv'    : function that retrieves the data via the provided callback: pbi.dsv(callback)
                e.g. pbi.dsv(function(data) { //Process data function });
 * - 'height' : height of the sandbox frame
 * - 'width'  : width of the sandbox frame
 * - 'colors' : color array with 8 colors; changable via options
 * 
 * Code is based on: https://bl.ocks.org/mbostock/4339083
 */

// ADD: translate function for the data 
function toJSON(data) {
  var flare = {
      name: "Position",
      children: []
    },
    levels = ["from_id", "c1", "c2", "c3", "c4", "c5"];

  // For each data row, loop through the expected levels traversing the output tree
  data.forEach(function(d) {
    // Keep this as a reference to the current level
    var depthCursor = flare.children;
    // Go down one level at a time
    levels.forEach(function(property, depth) {

      // Look to see if a branch has already been created
      var index;
      depthCursor.forEach(function(child, i) {
        if (d[property] == child.name) index = i;
      });
      // Add a branch if it isn't there
      if (isNaN(index)) {
        depthCursor.push({
          name: d[property],
          children: []
        });
        index = depthCursor.length - 1;
      }
      // Now reference the new child array as we go deeper into the tree
      depthCursor = depthCursor[index].children;
      // This is a leaf, so add the last element to the specified branch
      if (depth === levels.length - 1) depthCursor.push({
        name: d.product,
        size: d.revenue
      });
    });
  });
  // End of conversion
  return flare;
}

var margin = {
    top: 20,
    right: 120,
    bottom: 20,
    left: 120
  },
  width = pbi.width - margin.left - margin.right, // ALTER: Changed fixed width with the 'pbi.width' variable
  height = pbi.height - margin.top - margin.bottom; // ALTER: Changed fixed height with the 'pbi.height' variable

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("#chart") // ALTER: Select SVG object; no need to create it
  .attr("width", width + margin.left + margin.right) // ALTER: Add complete width
  .attr("height", height + margin.top + margin.bottom) // ALTER: Add complete height
  .append("g")
  .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

// ALTER: Replaced the d3.json function with the pbi variant: pbi.dsv
pbi.dsv(function(data) {
  var flare = toJSON(data); // ALTER: add extra convertion step to parent/child JSON
  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", height + margin.top + margin.bottom);

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 + ")";
    })
    .attr("r", function(d) {
      return d == null ? 0 : 3;
    })
    .on("click", click)
    .on("mouseover", function(ds, index) {
      var g = d3.select(this); // The node
      d3.select(this).attr("r", 10)
      // The class is used to remove the additional text later
      var info = g.append('text')
        .classed('info', true)
        .attr('x', -20)
        .attr('y', -15)
        .style("fill", function(d) {
          if (data[index].from_department == "engineering") {
            return "green";
          } else if (data[index].from_department == "procurement") {
            return "orange";
          } else if (data[index].from_department == "construction") {
            return "red";
          } else {
            return "black";
          }
        })
        .text(function(d, i) {
          return data[index].from_department + " to " + data[index].to_department;
        });
    })
    .on("mouseout", function() {
      // Remove the info text on mouse out.
      d3.select(this).select('text.info').remove();
      d3.select(this).attr("r", 6).style("fill", "black");
    });

  nodeEnter.append("circle")
    .attr("r", 1e-6)
    .style("fill", function(d) {
      return d._children ? pbi.colors[0] : pbi.colors[1];
    })


  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) {
      return d._children ? pbi.colors[0] : pbi.colors[1];
    });

  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);

  // 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);
}

＆＃13;

.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;
}

＆＃13;

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.0.0/d3.min.js"></script>

＆＃13;

如果涉及空值，我想停止扩展子值如果来自json结构的空值

，树枝将不会打开

先谢谢，请帮帮我

可折叠树不会在d3.js中展开空值（空值不会添加到分支中）

0 个答案: