Range input with v4

This is a demonstration of the use of the html 'range' input using d3.js v4.

This graph is part of the code samples for the update to the book D3 Tips and Tricks to version 4 of d3.js.

<!DOCTYPE html>
<meta charset="utf-8">
<title>Input test (circle)</title>
  
<p>
  <label for="nRadius" 
         style="display: inline-block; width: 240px; text-align: right">
         radius = <span id="nRadius-value">…</span>
  </label>
  <input type="range" min="1" max="150" id="nRadius">
</p>

var width = 600;
var height = 300;
 
var holder = d3.select("body")
      .append("svg")
      .attr("width", width)    
      .attr("height", height);

// draw the circle
holder.append("circle")
  .attr("cx", 300)
  .attr("cy", 150) 
  .style("fill", "none")   
  .style("stroke", "blue") 
  .attr("r", 120);

// when the input range changes update the circle 
d3.select("#nRadius").on("input", function() {
  update(+this.value);
});

// Initial starting radius of the circle 
update(120);

// update the elements
function update(nRadius) {

// adjust the text on the range slider
  d3.select("#nRadius-value").text(nRadius);
  d3.select("#nRadius").property("value", nRadius);

// update the rircle radius
  holder.selectAll("circle") 
    .attr("r", nRadius);
}

</script>

https://d3js.org/d3.v4.min.js