Add labels to bar chart D3

Question

I'm trying to add labels to my bar chart, and I can't make it work. I read a lot about it and tried many things already, but no success.

var margin = {top: 20, right: 20, bottom: 70, left: 40},
width = 600 - margin.left - margin.right,
height = 300 - margin.top - margin.bottom;


var parseDate = d3.timeParse("%Y-%m");

var x = d3.scaleBand().rangeRound([0, width]).paddingInner(0.05);

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

var xAxis = d3.axisBottom(x)
.tickFormat(d3.timeFormat("%Y-%m"));

var yAxis = d3.axisLeft(y)
.ticks(10);

var 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 + ")");

d3.csv("bar-data.csv", function(error, data) {

data.forEach(function(d) {
    d.date = parseDate(d.date);
    d.value = +d.value;
});

 x.domain(data.map(function(d) { return d.date; }));
 y.domain([0, d3.max(data, function(d) { return d.value; })]);

 svg.append("g")
  .attr("class", "x axis")
  .attr("transform", "translate(0," + height + ")")
  .call(xAxis)
.selectAll("text")
  .style("text-anchor", "end")
  .attr("dx", "-.8em")
  .attr("dy", "-.55em")
  .attr("transform", "rotate(-90)" );

svg.append("g")
  .attr("class", "y axis")
  .call(yAxis)
  .append("text")
  .attr("transform", "rotate(-90)")
  .attr("y", 6)
  .attr("dy", ".71em")
  .style("text-anchor", "end")
  .text("Value ($)");

svg.selectAll("bar")
  .data(data)
  .enter().append("rect")
  .style("fill", "steelblue")
  .attr("x", function(d) { return x(d.date); })
  .attr("width", x.bandwidth())
  .attr("y", function(d) { return y(d.value); })
  .attr("height", function(d) { return height - y(d.value); });


svg.selectAll("text")
 .data(data)
 .enter()
 .append("text")
 .text(function(d) {
 return d.value;
  })
  .attr("text-anchor", "middle")
  .attr("fill", "white")
  .attr("x", function(d, i) {
   return i * (width / data.length);
  })
  .attr("y", function(d) {
   return height - (d * 4);
 });

});

Here is my Plunker.

Any help is appreciated. Thank you in advance.

Answer 1

You can add labels to the bars using the snippet below -

  svg.selectAll(".text")        
  .data(data)
  .enter()
  .append("text")
  .attr("class","label")
  .attr("x", (function(d) { return x(d.date); }  ))
  .attr("y", function(d) { return y(d.value) - 20; })
  .attr("dy", ".75em")
  .text(function(d) { return d.value; });       

Your problem was here. The correct approach to get x-y positions for the labels would be the same approach you used for the bars using the x and y variables.

.attr("x", function(d, i) {
   return i * (width / data.length);
  })
  .attr("y", function(d) {
   return height - (d * 4);
 }); 

Updated Plunkr - https://plnkr.co/edit/e6HPuph3OSbpxeEVQXfF?p=preview