d3 arc text

//Create an SVG path (based on bl.ocks.org/mbostock/2565344)
svg.append("path")
    .attr("id", "wavy") //Unique id of the path
    .attr("d", "M 10,90 Q 100,15 200,70 Q 340,140 400,30") //SVG path
    .style("fill", "none")
    .style("stroke", "#AAAAAA");

//Create an SVG text element and append a textPath element
svg.append("text")
   .append("textPath") //append a textPath to the text element
    .attr("xlink:href", "#wavy") //place the ID of the path here
    .style("text-anchor","middle") //place the text halfway on the arc
    .attr("startOffset", "50%")
    .text("Yay, my text is on a wavy path");

[링크 : https://www.visualcinnamon.com/2015/09/placing-text-on-arcs.html]

[링크 : http://tutorials.jenkov.com/svg/path-element.html]

+2018.11.01

의외로 startOffset이 중요하다!

      svg.append('text')
        .append('textPath')
        .attr({
          startOffset: '50%',
          'xlink:href': '#curvedTextPath'
        })
        .text('Hello, world!');

[링크 : http://bl.ocks.org/jebeck/196406a3486985d2b92e]

[링크 : https://gist.github.com/jebeck/196406a3486985d2b92e]