Example of Small Multiples with Mouseover Tooltip (fixed)

forked from misanuk's block: Example of Small Multiples with Mouseover Tooltip

<!DOCTYPE html>
<meta charset="utf-8">

body {
  font: 10px avenir next, sans-serif;
}

.request-line {
  fill: none;
  stroke: steelblue;
  stroke-width: 1.5px;
}

.dimension-title {
  font: bold 14px avenir next;
}

.dimension-box {
  display: inline-block;
}

.x-axis {
  stroke-width: 0.5px;
  stroke: #888;
  font: 12px avenir next, sans-serif;
}

.x-axis > path {
  stroke: #888;
}

.y-axis {
  stroke-width: 0.5px;
  stroke: #888;
  font: 12px avenir next, sans-serif;
}

.y-axis > path {
  stroke: #888;
}

.overlay {
  fill: none;
  pointer-events: all;
}

.focus circle {
  fill: none;
  stroke: steelblue;
}
</style>

// Margin Conventions and Setup
var margin = {top: 0, right: 20, bottom: 15, left: 35};

var width = 250 - margin.left - margin.right;
var height = 200 - margin.top - margin.bottom;

// Format Functions
var parseTime = d3.timeParse("%Y-%m-%d");
var bisectDate = d3.bisector(function(d) { return d.month; }).left

// Line Defaults
var xScale = d3.scaleTime()
      .range([0, width]);

var yScale = d3.scaleLinear()
      .range([height, 0]);

var xAxis = d3.axisBottom()
      .scale(xScale)
      .ticks(2)
      .tickSize(0);

var yAxis = d3.axisLeft()
    .scale(yScale)
    .ticks(2)
    .tickSize(0);

var line = d3.line()
    .x(function(d) { return xScale(d.month); })
    .y(function(d) { return yScale(d.requests); });

d3.csv("category_monthly.csv", function(error, data) {
	if(error) throw error;

// Prep Data
	data.forEach(function(d) {
		d.month = parseTime(d.month);
		d.requests = +d.requests;
	})

//Update Scales
  xScale.domain(d3.extent(data, function(d) { return d.month; }));
  yScale.domain(d3.extent(data, function(d) { return d.requests; }));

// Nest Data
  var dataByDimension = d3.nest()
    .key(function(d) { return d.category; })
    .entries(data);

// Join Data and create plots
  var dimension = d3.select("body").selectAll(".dimension-group")
    .data(dataByDimension)
   .enter()
    .append("div")
    .attr("class", "dimension-box")

dimension.append("h3")
    .attr("class", "dimension-title")
    .text(function(d) { return d.key.slice(0,25); });

var svg = dimension.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 + ")");

svg.append("g")
    .attr("class", "x-axis")
    .attr("transform", "translate(0," + height + ")")
    .call(xAxis);

svg.append("g")
    .attr("class", "y-axis")
    .call(yAxis);

svg.append("path")
    .attr("class", "request-line")
    .attr("d", function(d) { return line(d.values); });

// Mouseover Tooltip, based on Mike's example here: https://bl.ocks.org/mbostock/3902569
svg.each(function(){
  var svg = d3.select(this),
      category = svg.datum().key;
  var filtered_data = svg.datum().values;
  
  var focus = svg.append("g")
      .attr("class", "focus")
      .style("display", "none");

focus.append("circle")
      .attr("r", 3);

focus.append("text")
      .attr("x", 9)
      .attr("dy", ".35em");

svg.append("rect")
      .attr("class", "overlay")
      .attr("width", width)
      .attr("height", height)
      .on("mouseover", function() { focus.style("display", null); })
      .on("mouseout", function() { focus.style("display", "none"); })
      .on("mousemove", mousemove);

function mousemove() {
    var x0 = xScale.invert(d3.mouse(this)[0]),
        i = bisectDate(filtered_data, x0, 1),
        d0 = filtered_data[i - 1],
        d1 = filtered_data[i],
        d = x0 - d0.month > d1.month - x0 ? d1 : d1;
    
    focus.attr("transform", "translate(" + xScale(d.month) + "," + yScale(d.requests) + ")");
    focus.select("text").text(d.requests);
  };
})

});

</script>

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