Replace a showR2 with a custom text in a Google Chart? - charts

Question

I am playing around with Google Chart to look a certain way. In this situation I have a combo chart a line and column chart.
I have stumble upon a view "layout" problems
How do replace the show2r legend with just some custom text? At
the moment says: y = 2.032E-4 * x - 8.203 r^2 = 7.005E-3 and I want
to replace it with "Trendline (Lineair)
2/ Also the legend gets a
1/2 and Arrows left and right. I like the legend to always be
visible?
3/ The x axis doesn't display all dates, how can I set that
as a default?
4/ How do I add vertical line in say month June??
Regards

Answer 1

to change the trendline label in the legend, use option --> labelInLegend
there are no standard options to change the value in the tooltip,
but it can be changed manually using event --> onmouseover
when the legend's position is top,
you can use option --> legend.maxLines
to increase the number of lines available and prevent the arrows...
to ensure all dates are shown on the x-axis,
allow enough room by using option --> chartArea.bottom
see following working snippet for examples of each...
google.charts.load('current', {
packages: ['corechart']
}).then(function () {
var data = google.visualization.arrayToDataTable([
['x', 'y0', 'y1'],
[new Date(2017, 11, 28), 175, 10],
[new Date(2017, 11, 29), 159, 20],
[new Date(2017, 11, 30), 126, 35],
[new Date(2017, 11, 31), 129, 40],
[new Date(2018, 0, 1), 108, 60],
[new Date(2018, 0, 2), 92, 70]
]);
var options = {
chartArea: {
bottom: 72
},
hAxis: {
slantedText: true
},
height: 400,
legend: {
maxLines: 2,
position: 'top'
},
tooltip: {
isHtml: true
},
trendlines: {
0: {
labelInLegend: '0-Linear Trend',
showR2: true,
type: 'linear',
visibleInLegend: true
},
1: {
labelInLegend: '1-Linear Trend',
showR2: true,
type: 'linear',
visibleInLegend: true
}
},
width: 400
};
var container = document.getElementById('chart_div');
var chart = new google.visualization.ColumnChart(container);
google.visualization.events.addListener(chart, 'onmouseover', function (props) {
var tooltipLabels = container.getElementsByTagName('span');
for (var i = 0; i < tooltipLabels.length; i++) {
if (tooltipLabels[i].innerHTML.indexOf('y =') > -1) {
tooltipLabels[i].innerHTML = 'CUSTOM TEXT:';
}
}
});
chart.draw(data, options);
});
<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="chart_div"></div>