d3 add text to circle

Question

I am trying to add some text into circle. I have been following example from a mbostock tutorial , but wasn't able to get the right output.

The code snippet is:

var data;
var code;

d3.json("/json/trace.json", function(json) {
  data = json;
  console.log(data);
  // get code for visualization
  code = data["code"];
  alert(code);
  var mainSVG = d3
    .select("#viz")
    .append("svg")
    .attr("width", 900)
    .attr("height", 900);
  mainSVG
    .append("circle")
    .style("stroke", "gray")
    .style("fill", "white")
    .attr("r", 100)
    .attr("cx", 300)
    .attr("cy", 300);
  circle = mainSVG.selectAll("circle").data([code]);
});

Any suggestions how to get this work?

Answer 1

Here is an example showing some text in circles with data from a json file: http://bl.ocks.org/4474971 . Which gives the following:

The main idea behind this is to encapsulate the text and the circle in the same " div " as you would do in html to have the logo and the name of the company in the same div in a page header.

The main code is:

var width = 960,
    height = 500;

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

d3.json("data.json", function(json) {
    /* Define the data for the circles */
    var elem = svg.selectAll("g")
        .data(json.nodes)

    /*Create and place the "blocks" containing the circle and the text */  
    var elemEnter = elem.enter()
        .append("g")
        .attr("transform", function(d){return "translate("+d.x+",80)"})

    /*Create the circle for each block */
    var circle = elemEnter.append("circle")
        .attr("r", function(d){return d.r} )
        .attr("stroke","black")
        .attr("fill", "white")

    /* Create the text for each block */
    elemEnter.append("text")
        .attr("dx", function(d){return -20})
        .text(function(d){return d.label})
})

and the json file is:

{"nodes":[
  {"x":80, "r":40, "label":"Node 1"}, 
  {"x":200, "r":60, "label":"Node 2"}, 
  {"x":380, "r":80, "label":"Node 3"}
]}

The resulting html code shows the encapsulation you want:

<svg width="960" height="500">
    <g transform="translate(80,80)">
        <circle r="40" stroke="black" fill="white"></circle>
        <text dx="-20">Node 1</text>
    </g>
    <g transform="translate(200,80)">
        <circle r="60" stroke="black" fill="white"></circle>
        <text dx="-20">Node 2</text>
    </g>
    <g transform="translate(380,80)">
        <circle r="80" stroke="black" fill="white"></circle>
        <text dx="-20">Node 3</text>
    </g>
</svg>

Answer 2

Extended the example above to fit the actual requirements, where circled is filled with solid background color, then with striped pattern & after that text node is placed on the center of the circle.

 var width = 960, height = 500, json = { "nodes": [{ "x": 100, "r": 20, "label": "Node 1", "color": "red" }, { "x": 200, "r": 25, "label": "Node 2", "color": "blue" }, { "x": 300, "r": 30, "label": "Node 3", "color": "green" }] }; var svg = d3.select("body").append("svg") .attr("width", width) .attr("height", height) svg.append("defs") .append("pattern") .attr({ "id": "stripes", "width": "8", "height": "8", "fill": "red", "patternUnits": "userSpaceOnUse", "patternTransform": "rotate(60)" }) .append("rect") .attr({ "width": "4", "height": "8", "transform": "translate(0,0)", "fill": "grey" }); function plotChart(json) { /* Define the data for the circles */ var elem = svg.selectAll("g myCircleText") .data(json.nodes) /*Create and place the "blocks" containing the circle and the text */ var elemEnter = elem.enter() .append("g") .attr("class", "node-group") .attr("transform", function(d) { return "translate(" + dx + ",80)" }) /*Create the circle for each block */ var circleInner = elemEnter.append("circle") .attr("r", function(d) { return dr }) .attr("stroke", function(d) { return d.color; }) .attr("fill", function(d) { return d.color; }); var circleOuter = elemEnter.append("circle") .attr("r", function(d) { return dr }) .attr("stroke", function(d) { return d.color; }) .attr("fill", "url(#stripes)"); /* Create the text for each block */ elemEnter.append("text") .text(function(d) { return d.label }) .attr({ "text-anchor": "middle", "font-size": function(d) { return dr / ((dr * 10) / 100); }, "dy": function(d) { return dr / ((dr * 25) / 100); } }); }; plotChart(json); 

 .node-group { fill: #ffffff; } 

 <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script> 

Output:

Below is the link to codepen also:

See the Pen D3-Circle-Pattern-Text by Manish Kumar ( @mkdudeja ) on CodePen .

Thanks, Manish Kumar

Answer 3

Here's a way that I consider easier: The general idea is that you want to append a text element to a circle element then play around with its "dx" and "dy" attributes until you position the text at the point in the circle that you like. In my example, I used a negative number for the dx since I wanted to have text start towards the left of the centre.

const nodes = [ {id: ABC, group: 1, level: 1}, {id:XYZ, group: 2, level: 1}, ]

const nodeElems = svg.append('g')
.selectAll('circle')
.data(nodes)
.enter().append('circle')
.attr('r',radius)
.attr('fill', getNodeColor)

const textElems = svg.append('g')
.selectAll('text')
.data(nodes)
.enter().append('text')
.text(node => node.label)
.attr('font-size',8)//font size
.attr('dx', -10)//positions text towards the left of the center of the circle
.attr('dy',4)