SliderAsObject

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.12/d3.min.js"></script>

CSS

.axis {
  font: 10px sans-serif;
  -webkit-user-select: none;
  -moz-user-select: none;
  user-select: none;
}

.domain {
  stroke: #000;
  stroke-opacity: .3;
  stroke-width: 5px;
}

.handle {
  fill: #fff;
  stroke: #000;
  stroke-opacity: .5;
  stroke-width: 1.25px;
  cursor: crosshair;
}

JavaScript

var Slider = function(g, scale) {

  this.margin = {
    top: 10,
    right: 10,
    bottom: 10,
    left: 10
  };
  this.slider_width = 250;
  this.slider_height = 80;

  this.scale = scale.range([0, this.slider_width]).clamp(true);
  this.g = g;

  this.brush = d3.svg.brush()
    .x(scale)
    .extent([0, 0]);

}

Slider.prototype.draw_slider = function() {

  var self = this;

  self.brush.on("brush", brushed);

  var slider_g = self.g.append("g")
    .attr("transform", "translate(" + self.margin.left + "," + self.margin.top + ")");

  slider_g.append("g")
    .attr("class", "slider_x_axis")
    .attr("transform", "translate(0," + self.slider_height / 2 + ")")
    .call(d3.svg.axis()
      .scale(x)
      .orient("bottom")
      .tickSize(0)
      .tickPadding(12));
      
  var slider = slider_g.append("g")
  .attr("class", "slider")
  .call(self.brush);
  
  slider.selectAll(".extent,.resize")
  .remove();
  
  self.handle = self.g.selectAll(".slider").append("circle")
  .attr("class", "handle")
  .attr("transform", "translate(0," + self.slider_height / 2 + ")")
  .attr("r", 9);

  function brushed() {
    var value = self.brush.extent()[0];

    if (d3.event.sourceEvent) { // not a programmatic event
      value = self.scale.invert(d3.mouse(this)[0]);
      console.log(value);
      self.brush.extent([value, value]);
    }

    self.handle.attr("cx", self.scale(value));
  }


}

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

var x = d3.scale.linear()
  .domain([0, 40]);



var slider_1 = new Slider(svg, x);
slider_1.draw_slider();