gene blocks

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    // Feel free to change or delete any of the code you see in this editor!
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)
    
		d3.json("data.json", function (error,json) {
			var geneGroups = d3.select("svg").selectAll("rect")
    		.data(json)
      	.enter()
				.append("g");

geneGroups.append("rect")
      	.attr("y", function (d) {
        		if (d.orientation == "forward") {return "100";}
        		if (d.orientation == "reverse") {return "125";}
        
      })
      	.attr("height", 50)
      	.attr("x", function (d) {return d.start})
      	.attr("width", function(d) {return d.stop - d.start})
      	.attr("stroke-width", 5)
      	.attr("stroke", "black")
      	.attr("fill", function (d) { 
        		if (d.orientation == "forward") {return "purple";}
        		if (d.orientation == "reverse") {return "gold";}
        
        
      });
      geneGroups.append("text")
      					.text(function (d) {return d.name})
      					.attr("x", function(d) {
        				return (d.start + (d.stop - d.start)/2)-8})
      					.attr("y", function (d) {
        		if (d.orientation == "forward") {return "133";}
        		if (d.orientation == "reverse") {return "160";}})
    						.style("font-size", 30)
      					.style("fill", "white")
      
      
      
    });
    
  </script>
</body>

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