I am currently trying to create a bar graph which represents data and is able to change based on a selection, but the bars are hard to read and make understanding the data difficult. I am trying to make a tooltip which shows the number of resources being used per project. Here is my code so far:
<!DOCTYPE html>
<html>
<head>
<meta>
<meta http-equiv="refresh" content="90">
<meta name="description" content="Drawing Shapes w/ D3 - BarChart" />
<meta charset="utf-8">
<title>Resources per Project</title>
<script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
<style type="text/css">
h1 {
font-size: 35px;
color: darkgrey;
font-family: Helvetica;
border-bottom-width: 3px;
border-bottom-style: dashed;
border-bottom-color: black;
}
h2 {
font-size: 20px;
color: black;
font-family: Helvetica;
text-decoration: underline;
margin-left: 350px;
margin-top: 2px;
}
</style>
</head>
<body>
<h1>Resources used per Project</h1>
<p>Choose Month:
<select id="label-option">
<option value="April">April</option>
<option value="May">May</option>
<option value="June">June</option>
<option value="July">July</option>
<option value="August">August</option>
<option value="September">September</option>
</select>
<script type="text/javascript">
var width = 800
var height = 500
var emptyVar = 0
var dataArrayProjects = ['2G', 'An', 'At', 'Au', 'AW', 'Ch', 'CI', 'CN']
var April = [0.35, 1.66, 3.04, 1.54, 3.45, 2.56, 2.29, 1.37]
var May = [0.36, 1.69, 3.08, 1.54, 3.62, 2.61, 2.22, 1.44]
var June = [0.34, 1.7, 3.08, 1.63, 3.66, 2.68, 2.24, 1.51]
var July = [0.3, 1.72, 3.17, 1.67, 3.56, 2.56, 2.17, 1.44]
var August = [0.28, 1.79, 3.18, 1.71, 3.62, 2.73, 2.26, 1.54]
var September = [1.23, 1.74, 3.12, 1.61, 3.66, 2.71, 2.2, 1.48]
var widthScale = d3.scale.linear()
.domain([0, 4])
.range([0, width - 60]);
d3.select("#label-option").on("change", change)
function change() {
var data = April;
if (this.selectedIndex == 1){
data = May;
} else if (this.selectedIndex == 2){
data = June;
} else if (this.selectedIndex == 3){
data = July;
} else if (this.selectedIndex == 4){
data = August;
} else if (this.selectedIndex == 5){
data = September;
}
canvas.selectAll("rect")
.data(data)
.attr("width", emptyVar)
.attr("height", 50)
.attr("fill", function(d) {
return color(d)
})
.attr("y", function(d, i) {
return i * 55
})
bars.transition()
.duration(1500)
.delay(200)
.attr("width", function(d) {
return widthScale(d);
})
}
var heightScale = d3.scale.ordinal()
.domain(dataArrayProjects)
.rangePoints([10, height - 85]);
var color = d3.scale.linear()
.domain([0, 4])
.range(["#000066", "#22abff"])
var axis = d3.svg.axis()
.ticks("10")
.scale(widthScale);
var yAxis = d3.svg.axis()
.scale(heightScale)
.orient("left");
var canvas = d3.select("body")
.append("svg")
.attr("width", width)
.attr("height", height)
.append("g")
.attr("transform", "translate(40, 0)");
var bars = canvas.selectAll("rect")
.data(April)
.enter()
.append("rect")
.attr("width", emptyVar)
.attr("height", 50)
.attr("fill", function(d) {
return color(d)
})
.attr("y", function(d, i) {
return i * 55
})
canvas.append("g")
.attr("transform", "translate(0, 430)")
.attr("font-family", "Helvetica")
.attr("font-size", "15px")
.call(axis);
canvas.append("g")
.attr("font-family", "Helvetica")
.attr("font-size", "15px")
.style("fill", "black")
.attr("class", "y axis")
.call(yAxis);
bars.transition()
.duration(1500)
.delay(200)
.attr("width", function(d) {
return widthScale(d);
})
var yAxisLine = canvas.append("line")
.attr("x1", -3)
.attr("y1", 0)
.attr("x2", -3)
.attr("y2", 436)
.attr("stroke-width", 6)
.attr("stroke", "black");
</script>
<h2>Resources</h2>
</body>
</html>How do I add a tooltip so that when you hover over one of the bars, the data number it represents is shown.
There are some plugins which are available like @mbox suggests foxToolTip and d3-tip etc.
Here I am not using any plugin, using CSS and JS to create it CSS
#myTooltip {
position: absolute;
text-align: left;
width: 80px;
height: auto;
min-height: 20px;
padding: 2px;
font: 12px sans-serif;
background-color: rgb(255, 255, 255);
border: 2px solid rgb(100, 161, 209);
color: #5E99BD;
border-radius: 8px 8px 8px 8px;
pointer-events: none;
padding: 11px;
}
#myTooltip:before {
box-sizing: border-box;
display: inline;
font-size: 18px;
width: 100%;
line-height: 1;
color: rgb(100, 161, 209);
content: "\25BC";
position: absolute;
text-align: center;
top: 100%;
left: -2px;
}
JS
You have to add one div which represents tooltip.
var tooplTipDiv = d3.select("body").append("div")
.attr("id", "myTooltip")
.style("opacity", 0);
And you should provide callbacks for mouseover and mouseout
var bars = canvas.selectAll("rect")
.data(April)
.enter()
.append("rect")
//add callbacks for onMouseOver and onMouseOut
.on("mouseover", onMouseOver)
.on("mouseout", onMouseOut)
.attr("width", emptyVar)
.attr("height", 50)
.attr("fill", function(d) {
return color(d)
})
.attr("y", function(d, i) {
return i * 55
})
And functions for mouseover and mouseout
function onMouseOver(d){
var tooltipDiv = d3.select("#myTooltip");
tooltipDiv.transition()
.duration(200)
.style("opacity", 1);
tooltipDiv.html( "your Content")
.style("left", (parseFloat(widthScale(d))) + "px")
.style("cursor", "pointer")
.style("top", function(d){
return d3.event.pageY - this.offsetHeight - 17 + "px"
})
.style("color", "#333333");
}
function onMouseOut(d){
var tooltipDiv = d3.select("#myTooltip");
tooltipDiv.transition()
.duration(500)
.style("opacity", 0);
}
If you have still some confusion, let me know, will post full working code.