how to highlight a bar in stacked bar chart d3.js v4 - d3.js

Question

I want to highlight a bar with April (value in x-axis) with a square box. but I am not getting a approach to do the same.
tried getting the co-ordinates of the respected bar, but unable to find a solution for the same
Unable to find the co-ordinates of the respective bar which I need to highlight.
what should be the approach for highlighting a bar with a square box in stacked bar chart d3.js v4
createStackedBarChart(130,300,10,60,20,45,"manager-line-graph-2");
function createStackedBarChart(height,width,top,right,bottom,left,id){
var margin = {top: top, right: right, bottom: bottom, left: left };
//console.log("margin"+margin);
var svg = d3.select("#"+id).append("svg"),
width = width - margin.left - margin.right,
height = height - margin.top - margin.bottom,
g = svg.attr("width", "100%")
.attr("height", height + margin.top + margin.bottom)
.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")");
var x = d3.scaleBand()
.rangeRound([0, width])
.padding(0.2)
.align(5.0);
var y = d3.scaleLinear()
.rangeRound([height, 0]);
var z = d3.scaleOrdinal()
.range(["#0000FF", "#00FFFF", "#81F781", "#F3F781", "#FE2E2E"]);
var data = [
{"Months": "Feb","Installation": 5,"Product": 10,"Payment": 15,"Billing": 20,"Outage": 25},
{"Months": "March","Installation": 6,"Product": 8,"Payment": 9,"Billing": 15,"Outage": 18},
{"Months": "April","Installation": 9,"Product": 12,"Payment": 24,"Billing": 17,"Outage": 14},
{"Months": "May","Installation": 9,"Product": 12,"Payment": 14,"Billing": 17,"Outage": 14},
{"Months": "June","Installation": 9,"Product": 12,"Payment": 15,"Billing": 11,"Outage": 10}
];
// fix pre-processing
var keys = [];
for (key in data[0]){
if (key != "Months")
keys.push(key);
}
console.log("value of keys are " + keys);
data.forEach(function(d){
d.total = 0;
keys.forEach(function(k){
d.total += d[k];
})
});
//data.sort(function(a, b) {
//return b.total - a.total;
//});
x.domain(data.map(function(d) {
return d.Months;
}));
y.domain([0, d3.max(data, function(d) {
return d.total;
})]).nice();
z.domain(keys);
g.append("g")
.selectAll("g")
.data(d3.stack().keys(keys)(data))
.enter().append("g")
.attr("fill", function(d) {return z(d.key);})
.selectAll("rect")
.data(function(d) { return d; })
.enter().append("rect")
.attr("x", function(d) {
return x(d.data.Months);
})
.attr("y", function(d) {
return y(d[1]);
})
.attr("height", function(d) {
return y(d[0]) - y(d[1]);
})
.attr("width", x.bandwidth()-5);
g.append("g")
.attr("class", "axis")
.attr("transform", "translate(0," + height + ")")
.call(d3.axisBottom(x).ticks(5));
g.append("g")
.attr("class", "axis")
.call(d3.axisLeft(y).ticks(5, "s"))
.append("text")
.attr("x", 2)
.attr("y", y(y.ticks(5).pop()))
.attr("dy", "0.32em")
.attr("fill", "#000")
.attr("font-weight", "bold")
.attr("text-anchor", "start")
var legend = g.append("g")
.attr("font-family", "sans-serif")
.attr("font-size", 10)
.attr("text-anchor", "end")
.selectAll("g")
.data(keys.slice().reverse())
.enter().append("g")
.attr("transform", function(d, i) {
return "translate(0," + i * 20 + ")";
});
//legend.append("rect")
//.attr("x", width + 20)
//.attr("width", 10)
//.attr("height", 10)
//.attr("fill", z);
legend.append("circle")
.attr("r",5)
.attr("cx", width+30)
.attr("cy", 0)
.attr("fill",z);
legend.append("text")
.attr("x", width + 88)
.attr("y", 3.5)
.attr("dy", "0.12em")
.text(function(d) {
return`enter code here` d;
});
}

Answer 1

One solution I have used previously is to create an invisible layer of bars for the same data. Then use the .on("mouseover", function...); to make the bars for that data visible again by changing the styles or the fill opacity.
Here is a sample bl.ock with what I mean. It is a grouped bar chart with ordinal scale, but the same could be applied to your data with some tweaking.
https://bl.ocks.org/Coola85/b05339b65a7f9b082ca210d307a3e469
Update May 5, 2018: upon further reading I see your issue is different than the solution I suggested. This link might give you a good starting point of how to use an if statement to selectively highlight particular data.
so you could use the following style for your rect
.style ("fill", function(d) {
if (d.Months === "April") {return "red"} // <== Add these
else { return "black" }
})