I have a component code like below
changeData() {
const changedData = this.getData();
this.chartData = Object.assign({}, changedData);
this.lineTooltips = this.getLineTooltips();
this.chartOptions = {
tooltips: {
enabled: true,
callbacks: {
label: function(tooltipItem, data) {
return (data.tooltips[tooltipItem.index]).split('#');
},
}
}
}
}
and also HTML file
<div class="chartStyle">
<p-chart type="line" [data]="chartData" responsive="true" [options]="chartOptions" (onDataSelect)="selectData($event)"></p-chart>
The chart can load the line and data, but I hover to each item on the chart, the callback function did not work to load tooltip.
If you log data.tooltips you will see its undefined, and since you try to read things from it it will throw an error and not draw anything.
Looking at the documentation I think you have to replace data.tooltips with data.datasets. (https://www.chartjs.org/docs/latest/configuration/tooltip.html#label-callback)
The best thing you can do is just log both tooltipItem and data and go through the objects to see how you can combine them to get to the point you need and then insert that in your callback.
Related
I have tried a lot of it, but nothing seems to be working as expected.
I need to show the text inside the pie chart.
For the above, I tried using chartjs-plugin-datalabels but then used a formatter to change a value to a value with a percentage.
formatter: function(value:any, context:Context) {
return Math.floor(value) + '%';
},
But that affected both the data point (i.e: [11,200] is by data, I only need to add a percentage to the first data point and not to the second. Show 11% and 200.)
Code:
import ChartDataLabels,{Context} from 'chartjs-plugin-datalabels';
ChartJS.register(ArcElement, Tooltip, Legend, ChartDataLabels);
export const options = {
responsive: true,
maintainAspectRatio: false,
plugins: {
datalabels: {
formatter: function(value:any, context:Context) {
return Math.floor(value) + '%';
},
color:"white",
font: {
size: 16,
weight:'bold'
}
},
title: {
display: true,
},
legend: {
display: false,
},
},
};
function MyChart(){
return(
<Pie data={dataChart} options={options} />
)
}
In the above code options in the Pie, the component shows a typescript error while using chartjs-plugin-datalabels library.
The expected type comes from property 'options' which is declared here on type 'IntrinsicAttributes & Omit<ChartProps<"doughnut", number[], unknown>, "type"> & { ref?: ForwardedRef<ChartJSOrUndefined<"doughnut", number[], unknown>> | undefined; }'
2: I need to show text in the center of a Doughnut chart but seems impossible with the library and reactchartjs2 don't have a feature to show text in charts. Tried a possible solution at Add text inside the Doughnut chart of the React-Chartjs-2 box to react but none helped.
I would like to force a loading state on apexchart, while changing it's data using setInterval.
See example for loading each interval here: React ApexCharts update chart with interval
I can use the noData option, but it'll work only for the first time
See noData example here
How to show "loading..." text as a placeholder before my Apexcharts actually loads?
How can i force a "Loading..." message each setInterval call, before calling the server?
I wrote this function (seriesArrState is the array of serieses), but I wonder if there's a better option
const emptyChart = () => {
chart?.updateOptions({
series: seriesArrState.map((series) => {
return { ...series, data: [] };
}),
annotations: { points: [], xaxis: [] },
xaxis: {
labels: {
show: false,
},
},
});
});
};
I'm using chartjs with Bootstrap 4, on version 2.6.0.
Everything is working fine, except that I'm trying to replace an information when value is 0 on tooltip to not voted yet
I've tried a lot, and can't figure it out.
Graph picture
Can you help me?
There's an image attached that illustrates.
The value should still be zero inside the Graph, but I need to translate this information on the tooltip when the value is 0.
My code already has this information:
tooltips: {
custom: function(tooltip) {
if (!tooltip) return;
// disable displaying the color box;
tooltip.displayColors = false;
},
callbacks: {
title: function(tooltipItem, data) {
return this._data.labels[tooltipItem[0].index];
}
}
},
Thanks a lot.
Edit: Here is the second image after the suggested fix.
I'm not good with it but this will get it done. You might have to work it differently. But if you put how you are creating your chart then I can make it an exact match. Essentially you will want this:
callbacks: {
title: function(tooltipItem, data) {
return this._data.labels[tooltipItem[0].index];
},
label: function(tooltipItem, data){
var lab = data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index];
return lab === 0 ? "Não Avaliado" : "Avaliação Geral: " + lab;
}
}
Is it possible to adjust the tooltips displayed in a line chart rendered using Chart.js 2.4.0?
It recently shows both x and y value and the name of the dataset. I would need only the name of the dataset.
You can change the configuration for tooltip in options. In tooltip, we have callback object. In which, you set the title to a custom function that returns the title you want to give to the tooltip.
[sample-code]
var chartInstanceHoverModeNearest = new Chart(ctx, {
type: 'bar',
data: data,
options:{
events:["click"],
title : {
display : true
},
scales: {
xAxes: [{
categorySpacing: 0
}]
},
tooltips: {
enabled: true,
callbacks : {
title : function(){
return "Your Custom Title";
},
label : function(){
return "";
}
}
}
}
});
Below are the methods in callback object. If you want to extend more you can override these methods to give custom functionality
callbacks : {
afterBody:(),
afterFooter:(),
afterLabel:(),
afterTitle:(),
beforeBody:(),
beforeFooter:(),
beforeLabel:(),
beforeTitle:(),
footer:(),
label:(tooltipItem, data),
labelColor:(tooltipItem, chartInstance),
title:(tooltipItems, data)
}
I am using chart.js to show a line chart. How can I hide a tooltip label for a chart.js line chart? The label in the tooltip is showing undefined so I want to hide the label (please see the screenshot)?
Perhaps there is a way to modify tooltip where I can show only the legends value in tooltip? My code is as follows:
myLine = new Chart(ctx).Line(lineChartData, {
type: 'line',
responsive: true,
scaleShowGridLines : false,
bezierCurve : false,
animationEasing: "linear",
tooltipEvents: ["mousemove", "touchstart", "touchmove"],
showTooltips: true,
scaleLineColor: "rgba(0,0,0,.8)",
});
Just set the tooltipTitleFontSize to 0 in your options.
Preview
Script
myLine = new Chart(ctx).Line(lineChartData, {
...
tooltipTitleFontSize: 0
});
I know I am late, but I guess it still has merit to add this one.
check this : https://stackoverflow.com/a/44632748/12061669
It uses a function to hide the title:
options:{
tooltips:{
callbacks:{
title: ()=>{}
}
}
}
Setting the title's font size to zero is not ideal as you will still see an (ugly) extra space on top of the tooltip, as if the title line is still there - which honestly is what you'd expect.
Instead, I used Yumin Gui's answer but had to return null for it to work:
`
tooltips: {
callbacks: {
title: () => null,
},
},
The result is exactly as in the pie charts (which does not have a title in its default tooltips).
To hide the tooltip title/label, it should be added in the options object for that chart as follows:
options: {
plugins: {
tooltip: {
callbacks: {
title : () => null // or function () { return null; }
}
}
}
}
Do refer to the documentation to understand better that it should be handled with a custom callback function, and it is not a config that can be set in options directly.
The accepted answer won't work in newer versions of chart.js, as Aman said in comments, what you can use now is this:
tooltips: { titleFontSize: 0 }
Example:
var bar_chart = document.getElementById('bar_canvas').getContext('2d');
window.myBar = new Chart(bar_chart, {
type: 'bar',
data: bar_chart_data,
options: {
tooltips: {
titleFontSize: 0,
bodyFontSize: 14,
}
}
});