Question

我在rails中有一个查询，如下所示：

   class User < ActiveRecord::Base
        has_many :relationships

      def self.including_relationships
        User.joins("INNER JOIN relationships ON users.id = relationships.source").select("users.name, users.`group`, relationships.source, relationships.target, relationships.value").each_with_object(Hash.new{|h, k| h[k] = []}) do |a, obj| 


          obj['nodes'] << a.slice('name','group')
          obj['links'] << a.slice('source', 'target', 'value')
        end
      end
    end

导致以下json：

{"nodes":[
{"name":"A Voluptatem Quo","group":2},{"name":"Debitis Ut","group":1},{"name":"A Voluptatem Quo","group":2},{"name":"Eos","group":1},{"name":"Eos","group":1},{"name":"Debitis Ut","group":1},{"name":"Debitis Ut","group":1},{"name":"Placeat Aliquam Cumque","group":5},{"name":"Placeat Aliquam Cumque","group":5},{"name":"Placeat Aliquam Cumque","group":5},{"name":"Debitis Ut","group":1},{"name":"Error In","group":4},{"name":"Eos","group":1},{"name":"A Voluptatem Quo","group":2}],

"links":[

{"source":1,"target":1,"value":4},{"source":4,"target":1,"value":4},{"source":1,"target":3,"value":4},{"source":3,"target":5,"value":2},{"source":3,"target":5,"value":4},{"source":4,"target":1,"value":5},{"source":4,"target":5,"value":1},{"source":5,"target":5,"value":2},{"source":5,"target":5,"value":1},{"source":5,"target":3,"value":5},{"source":4,"target":4,"value":3},{"source":2,"target":2,"value":5},{"source":3,"target":1,"value":5},{"source":1,"target":5,"value":2}]}

我希望节点是唯一的，而不是像在这里一样重复。因此我改变了

的代码

obj['nodes'] << a.slice('name','group')

到

obj['nodes'] << a.slice('name','group')
obj['nodes'] = obj['nodes'].uniq

那给了我

{"nodes":[{"name":"A Voluptatem Quo","group":2},{"name":"Debitis Ut","group":1},{"name":"Eos","group":1},{"name":"Placeat Aliquam Cumque","group":5},{"name":"Error In","group":4}],"links":[{"source":1,"target":1,"value":4},{"source":4,"target":1,"value":4},{"source":1,"target":3,"value":4},{"source":3,"target":5,"value":2},{"source":3,"target":5,"value":4},{"source":4,"target":1,"value":5},{"source":4,"target":5,"value":1},{"source":5,"target":5,"value":2},{"source":5,"target":5,"value":1},{"source":5,"target":3,"value":5},{"source":4,"target":4,"value":3},{"source":2,"target":2,"value":5},{"source":3,"target":1,"value":5},{"source":1,"target":5,"value":2}]}

太棒了！正是我想要的。虽然现在d3.js没有给我我想要的图表。

查看javascript我得到错误：

  Uncaught TypeError: Cannot read property 'weight' of undefined.

然而。如果我不使用uniq，我不会收到此错误。 json看起来格式很好，所以我不知道为什么会出现这个错误。

d3代码如下：

var width = 960,
    height = 500;

var color = d3.scale.category20();

var force = d3.layout.force()
    .charge(-10)
    .linkDistance(230)
    .size([width, height]);

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height);

var endpoint = window.location.href+".json"

d3.json(endpoint, function(graph) {
  force
      .nodes(graph.nodes)
      .links(graph.links)
      .start();

  var link = svg.selectAll(".link")
      .data(graph.links)
    .enter().append("line")
      .attr("class", "link")
      .style("stroke-width", function(d) { return Math.sqrt(d.value); });

  var node = svg.selectAll(".node")
      .data(graph.nodes)
    .enter().append("circle")
      .attr("class", "node")
      .attr("r", 5)
      .style("fill", function(d) { return color(d.group); })
      .call(force.drag);

  node.append("title")
      .text(function(d) { return d.name; });

  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("cx", function(d) { return d.x; })
        .attr("cy", function(d) { return d.y; });
  });
});

修改了json的d3.js错误，只给出了我唯一的值

0 个答案: