Simple d3 v5 tooltips

This is a follow on from the simple scatterplot used as an example in the book D3 Tips and Tricks.

It is aimed at demonstrating a simple tooltip using d3.js and should be taken in context with the text of the book which can be downloaded for free from Leanpub.

forked from d3noob's block: Simple d3.js tooltips

<!DOCTYPE html>
<meta charset="utf-8">
<style> /* set the CSS */

body { font: 12px Arial;}

path {
  stroke: steelblue;
  stroke-width: 2;
  fill: none;
}

.axis path,
.axis line {
  fill: none;
  stroke: grey;
  stroke-width: 1;
  shape-rendering: crispEdges;
}

div.tooltip {
  color: white;
  position: absolute;
  text-align: center;
  width: 60px;
  height: 28px;
  padding: 2px;
  font: 12px sans-serif;
  background: rgba(0,0,0,.8);
  border: 2px solid black;
  pointer-events: none;
}
</style>
<body>

<script src="https://d3js.org/d3.v5.min.js"></script>
<script>
// Set the dimensions of the canvas / graph
const margin = {
  top: 30,
  right: 20,
  bottom: 30,
  left: 50
};
const width = 600 - margin.left - margin.right;
const height = 270 - margin.top - margin.bottom;

// Parse the date / time
const parseDate = d3.timeParse('%d-%b-%y');
const formatTime = d3.timeFormat('%e %B');

// Set the ranges
const x = d3.scaleTime().range([0, width]);
const y = d3.scaleLinear().range([height, 0]);

// Define the axes
const xAxis = d3.axisBottom(x).ticks(5);

const yAxis = d3.axisLeft(y)
  .ticks(5);

// Define the line
const valueline = d3.line()
  .x(d => x(d.date))
  .y(d => y(d.close));

// Define the div for the tooltip
const div = d3
  .select('body')
  .append('div')
  .attr('class', 'tooltip')
  .style('opacity', 0);

// Adds the svg canvas
const svg = d3
  .select('body')
  .append('svg')
  .attr('width', width + margin.left + margin.right)
  .attr('height', height + margin.top + margin.bottom)
  .append('g')
  .attr('transform', 'translate(' + margin.left + ',' + margin.top + ')');

// Get the data
d3.csv('data.csv').then(data => {
  data.forEach(d => {
    d.date = parseDate(d.date);
    d.close = +d.close;
  });

// Scale the range of the data
  x.domain(d3.extent(data, d => d.date));
  y.domain([0, d3.max(data, d => d.close)]);

// Add the valueline path.
  svg
    .append('path')
    .attr('class', 'line')
    .attr('d', valueline(data));

// Add the scatterplot
  svg
    .selectAll('dot')
    .data(data)
    .enter()
    .append('circle')
    .attr('r', 5)
    .attr('cx', d => x(d.date))
    .attr('cy', d => y(d.close))
    .attr('stroke-width', '20px')
    .attr('stroke', 'rgba(0,0,0,0)')
    .style('cursor', 'pointer')
    .on('mouseover', d => {
      div
        .transition()
        .duration(200)
        .style('opacity', 0.9);
      div
        .html(formatTime(d.date) + '<br/>' + d.close)
        .style('left', d3.event.pageX + 'px')
        .style('top', d3.event.pageY - 28 + 'px');
    })
    .on('mouseout', () => {
      div
        .transition()
        .duration(500)
        .style('opacity', 0);
    });

// Add the X Axis
  svg
    .append('g')
    .attr('class', 'x axis')
    .attr('transform', 'translate(0,' + height + ')')
    .call(xAxis);

// Add the Y Axis
  svg
    .append('g')
    .attr('class', 'y axis')
    .call(yAxis);
});

</script>
</body>

Modified http://d3js.org/d3.v5.min.js to a secure url

https://d3js.org/d3.v5.min.js