B. Clay Shannon B. Clay Shannon - 1 month ago 20
CSS Question

How can I reduce the spacing between my legend and chart proper in my Chart.JS bar chart, and increase it in the graph area?

I'm generating a Chart.JS bar chart that renders like so:

enter image description here

As you can see, the bottom of the legend and the top of the grid/graph are crammed together. Also, the individual bars are scrunched together more than strictly necessary, making the values a little hard to read; note that there is plenty of room left of the red bar and right of the blue bar. And there is plenty of space in the quadrant itself to add a shim or shiv of space between the legend the grid/graph.

How can I "air out" these elements to make the data more legible and the presentation more appealing?

Here is the code being used:

HTML

<div class="row">
<div class="col-md-6">
<div class="bottomleft">
<h2 class="sectiontext">Forecast/Impact Analysis</h2>
<div class="graph_container">
<canvas id="forecastLineChart"></canvas>
</div>
</div>
</div>
. . .


CSS

The "row" and "col-md-6" classes are Bootstrap. "graph_container" must be a Chart.JS class (it's not one of mine).

.bottomleft {
margin-left: 16px;
padding: 16px;
border: 1px solid black;
}

.sectiontext {
font-size: 1.5em;
font-weight: bold;
font-family: Candara, Calibri, Cambria, serif;
color: green;
margin-top: -4px;
}


JAVASCRIPT/jQuery

var ctxForecastChart = $("#forecastLineChart");
var forecastChartData = {
labels: ["Total Sales"],
datasets: [
{
label: "8/28/2016 - 9/3/2016",
backgroundColor: "rgba(255,0,0,0.75)",
hoverBackgroundColor: "rgba(255,0,0,1)",
data: [1631437.17]
},
{
label: "9/4/2016 - 9/10/2016",
backgroundColor: "rgba(255,153,0,0.75)",
hoverBackgroundColor: "rgba(255,153,0,1)",
data: [1523898.94]
},
{
label: "9/11/2016 - 9/17/2016",
backgroundColor: "rgba(255,255,0,0.75)",
hoverBackgroundColor: "rgba(255,255,0,1)",
data: [1755669.93]
},
{
label: "9/18/2016 - 9/24/2016",
backgroundColor: "rgba(0,255,0,0.75)",
hoverBackgroundColor: "rgba(0,255,0,1)",
data: [1873205.42]
},
{
label: "9/25/2016 - 10/1/2016",
backgroundColor: "rgba(0,0,255,0.75)",
hoverBackgroundColor: "rgba(0,0,255,1)",
data: [1838204.79]
}]
};

var forecastOptions = {
tooltips: {
enabled: true
},
animation: {
duration: 500,
easing: "easeOutQuart",
onComplete: function () {
var ctx = this.chart.ctx;
ctx.font
Chart.helpers.fontString(Chart.defaults.global.defaultFontFamily, 'normal'
Chart.defaults.global.defaultFontFamily);
ctx.textAlign = 'center';
ctx.textBaseline = 'bottom';

this.data.datasets.forEach(function (dataset) {
for (var i = 0; i < dataset.data.length; i++) {
var model = dataset._meta[Object.keys(dataset._met
[0]].data[i]._model, scale_max = dataset._meta[Object.keys(dataset._met
[0]].data[i]._yScale.maxHeight;
ctx.fillStyle = '#444';
var y_pos = model.y - 5;
if ((scale_max - model.y) / scale_max >= 0.93)
y_pos = model.y + 20;
ctx.fillText(addCommas(dataset.data[i]), model.x
y_pos);
}
});
}
}
};

var forecastBarChart = new Chart(ctxForecastChart, {
type: 'bar',
data: forecastChartData,
options: forecastOptions
});


UPDATE



It's not a complete solution, but I improved it this way:

<canvas id="forecastLineChart" height="190"></canvas>


IOW, I added the height value to the canvas, so that the grid/graph now fills the quadrant better:

enter image description here

It sill could use commas, perhaps, for the y axis numbers, and the bars could spread out horizontally more, though.

Answer

Inside your variable forecastOptions, you just need to add the so-called scales option.

var forecastOptions = {
    scales: {
        xAxes: [{
            barPercentage: 0.7,
            categoryPercentage: 1
        }]
    },
    tooltips...

This adjusts the width of the bars (barPercentage) and that of all the bars as a whole (categoryPercentage)

You can change 0.7 to however wide you want it to get. The extra space around all the bars is due to the fact that they fall under the same category, and that option is set to 0.8 as default, meaning that the 5 bars will only take up 80% as a whole.

Hope this helps

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