Assignment 5 - Interactivity D3

<!DOCTYPE html>
<meta charset="utf-8">
<style>
.axis--x path {
  display: none;
}
.line {
  fill: none;
  stroke: steelblue;
  stroke-width: 1.5px;
}
</style>
<svg width="960" height="500"></svg>
<script src="//d3js.org/d3.v4.min.js"></script>

//ADDED: Method for brushing
  d3.selection.prototype.moveToFront = function(name) {
  return this.each(function(){
    this.parentNode.parentNode.appendChild(this.parentNode);
    });
  };
var scaledX, xAxis, areaPath, area, box;
d3.tsv("data.tsv", type, function(error, data) {
  if (error) throw error;
  var cities = data.columns.slice(1).map(function(id) {
    return {
      id: id,
      values: data.map(function(d) {
        return {date: d.date, temperature: d[id]};
      })
    };

});

x.domain(d3.extent(data, function(d) { return d.date; }));
  y.domain([
    d3.min(cities, function(c) { return d3.min(c.values, function(d) { return d.temperature; }); }),
    d3.max(cities, function(c) { return d3.max(c.values, function(d) { return d.temperature; }); })
  ]);
  z.domain(cities.map(function(c) { return c.id; }));

//ADDED: variables/methods for zoom function
  var zoom = d3.zoom()
      .scaleExtent([1, Infinity])
      .translateExtent([[0, 0], [width, height]])
      .extent([[0,0], [width, height]])
      .on("zoom", zoomed);
  xAxis = d3.axisBottom(x);
  scaledX = g.append("g")
                  .attr("class", "axis axis--x")
                  .attr("transform", "translate(0," + height + ")")
                  .call(xAxis);

//ADDED: was to be used for clipping, but no changes even when called in the paths?
  box = svg.append("rect")
                .attr("class", "box")
                .attr("x", 10)
                .attr("y", 10)
                .attr("width", width-1)
                .attr("height", height-1)
                .attr("fill", "none")
                .attr("opacity", 0)
                .attr("pointer-events", "all")
                .call(zoom)
                .style("stroke-width", 0);
  //ADDED: for clipping, which doesn't work
  
  g.append("clipPath")
    .attr("id", "clipper")
    .append("rect")
    .attr("x", 1)
    .attr("y", 1)
    .attr("width", width )
    .attr("height", height);
  //

g.append("g")
      .attr("class", "axis axis--y")
      .call(d3.axisLeft(y))
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", "0.71em")
      .attr("fill", "#000")
      .text("Temperature, ºF");
  var city = g.selectAll(".city")
    .data(cities)
    .enter().append("g")
      .attr("class", "city");

city.append("path")
      .attr("class", "line")
      .attr("d", function(d) { return line(d.values); })
      //ADDED: id per notes
      .attr("id", function(d){
        return d.id.substring(0,3).toUpperCase();
      })
      .attr("opacity", 1)
      .style("stroke", function(d) { return z(d.id); });
  city.append("text")
      .datum(function(d) { return {id: d.id, value: d.values[d.values.length - 1]}; })
      .attr("transform", function(d) { return "translate(" + x(d.value.date) + "," + y(d.value.temperature) + ")"; })
      .attr("x", 3)
      .attr("dy", "0.35em")
      .style("font", "10px sans-serif")
      .text(function(d) { return d.id; })

//ADDED: hovering functions
      .on("mouseover", function(){
        var cityID = d3.select(this).text().substring(0,3).toUpperCase();
        var opac = svg.select("path#"+cityID).style("opacity");
        if(opac == 0)
        {
          //don't do anything
        }
        else
        {
          d3.select(this).moveToFront(cityID);
          //change all lines to gray except for this one
          d3.select(".path").style("stroke", 2);
          var path = svg.selectAll("path");
          svg.selectAll("path").style("stroke", "lightgray");
          svg.select("path#"+cityID).style("stroke", function(d) { 
            return z(d.id); });
          svg.select("path#"+cityID).style("opacity", 1);
        }
      })

.on("mouseout", function(){
        var cityID = d3.select(this).text().substring(0,3).toUpperCase();
        var opac = svg.select("path#"+cityID).style("opacity");
        if(opac == 0)
        {
          //don't do anything
        }
        else
        {
          svg.select("path#"+cityID).style("stroke-width", 1.5);
          var circleUnderMouse = this;
          svg.selectAll("path").style("stroke", function(d) {
            //check that the path is not null (2 empty arrays)
            if(!(d==null))
            {return z(d.id); }
          })
        }
      })
      .on("click", function(){
        var cityID = d3.select(this).text().substring(0,3).toUpperCase();
        var opac = svg.select("path#"+cityID).style("opacity");
        if(opac == 0)
        {
          svg.select("path#"+cityID).style("opacity", 1);
        }
        else
        {
         svg.select("path#"+cityID).style("opacity", 0); 
        }
        svg.selectAll("path").style("stroke", function(d) {
            //check that the path is not null
            if(!(d==null))
            {
              return z(d.id);
            }
          })
      });
});
function type(d, _, columns) {
  d.date = parseTime(d.date);
  for (var i = 1, n = columns.length, c; i < n; ++i) d[c = columns[i]] = +d[c];
  return d;
}
function zoomed() {
  svg.selectAll(".city").attr("transform", d3.event.transform);
  d3.selectAll(".line").style("stroke-width", 2/d3.event.transform.k);
  scaledX.call(xAxis.scale(d3.event.transform.rescaleX(x)));
}
</script>

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