Adding arrows and text to nodes in d3js Force Layout

Question

I have been trying to add text and arrow to a d3js force layout diagram but was not being able to get the desired results.

My script looks like the following:

var width = 600;
height = 400;

var color = d3.scale.category20();

var force = d3.layout.force()
    .charge(-120)
    .linkDistance(100)
    .size([width, height]);

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

d3.json("topology.json", function(error, graph) {
  if (error) throw error;

  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 2*(d.value); });//Math.sqrt

  var node = svg.selectAll(".node")
      .data(graph.nodes)
      .enter().append("circle")
      .attr("class", "node")
      .attr("r", 10)
      .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; });
  });
});

I tried to add the following snippet to add text

  node.append("text")
  .attr("x", 12)
  .attr("dy", ".35em")
  .text(function(d) { return d.name; });  

The sample json data is

{
    "nodes": [{
        "name": "0",
        "group": 2
    }, {
        "name": "1",
        "group": 2
    }, {
        "name": "2",
        "group": 2
    }, {
        "name": "3",
        "group": 1
    }],
    "links": [{
        "source": 0,
        "target": 1,
        "value": 1
    }, {
        "source": 1,
        "target": 3,
        "value": 2
    }, {
        "source": 2,
        "target": 3,
        "value": 1
    }]
}

Any help with adding text to the circles and arrows would be great. Sorry if I sounded a noob.

Thanks :) :)

Answer 1

Mobashyr,I have used the below sample for fulfill my requirement :

// Restart the force layout.
  var force.nodes(nodes) 
        .links(links)
        .charge(-1000)
        .linkDistance(120)
        .alpha(-15)
        .start();   

    var link = vis.selectAll(".link")
        .data(links);

    link.enter().insert("svg:line", ".node")
        .attr("class", "link")
        .style("stroke", "#ccc")
        .attr("cursor", "pointer")
        .style("stroke-width", "0")
        .style("stroke-width", function(d) { return d.weight;})
        .on("mouseover", function() { d3.select(this).style("stroke", "#555555").attr("stroke-opacity", "1.0").attr("stroke-width","10");})
        .on("mouseout", function() { d3.select(this).style("stroke", "#ccc").attr("stroke-opacity", "1.0").attr("stroke-width","4") });

    link.exit().remove();

    var node = vis.selectAll("g.node")
        .data(nodes)

    var groups = node.enter().append("g")
        .attr("class", "node")
        .attr("id", function (d) {
            return d.entityType;
        })
        .on('click', click)

    groups.append("circle")
       .attr("cursor", "pointer")
       .style("fill", function(d) { return color(d.entityType); })
       .style("fill", "#fff")
       .style("stroke-width", "0")
       .style("stroke", "#ddd")
     .attr("r", 20);

 groups.append("text")
        .attr("dy", 18)
        .style("font-size", "2.5px")
        .style("text-anchor", "middle")
        .style('fill','#000')
        .attr("refX", 15)
        .attr("refY", -1.5)
        .text(function (d) {
            return d.text;
        });

node.exit().remove();

 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 + ")";
        });