Total of values in Highcharts

carrarachristophe

Link to test case:
Debugger code (debug.datatables.net):
Error messages shown:
Description of problem:

Hello,
I am using Highcharts and am able to display the Datatable data in a pie chart.
What I am trying to do now is to add the total number of records displayed in the datatable somewhere in the Highcharts.
There are a couple of Stackoverflow cases like this one or that one and this is a working example with the total in the top left corner.

I fail to do the same and only get the following: Total: 0.

Here is my code

    var chart_type = Highcharts.chart("container_type", {
        chart: {
            type: 'pie',
            events: {
                load: function(event) {
                    var total = 0; // get total of data
                    for (var i = 0, len = this.series[0].yData.length; i < len; i++) {
                        total += this.series[0].yData[i];
                    }
                    var text = this.renderer.text(
                        'Total: ' + total,
                        this.plotLeft,
                        this.plotTop - 20
                    ).attr({
                        zIndex: 5
                    }).add() // write it to the upper left hand corner              }
                }
            },
        title: {
            text: 'Prochains achats par type',
            align: 'center',
            style: {
                font: '24px "Helvetica Neue", Helvetica, Arial, sans-serif'
            }
        },
        series: [
            {
                data: chartData_type(table),
                name: 'Voeux',
            },
        ],
        plotOptions: {
            pie: {
                allowPointSelect: true,
                cursor: 'pointer',
                dataLabels: {
                    enabled: true,
                    format: '<b>{point.name}</b>: {point.y} ({point.percentage:.1f}%)',
                    style: {
                        font: '14px "Helvetica Neue", Helvetica, Arial, sans-serif'
                    }
                }
            }
        }
    });

function chartData_type(table) {
    var counts = {};
 
    // Count the number of entries for each position
    table
        .column(4, { search: 'applied' })
        .data()
        .each(function (val) {
            if (counts[val]) {
                counts[val] += 1    ;
            } else {
                counts[val] = 1;
            }
        });
 
    // And map it to the format highcharts uses
    return $.map(counts, function (val, key) {
        return {
            name: key,
            y: val,
        };
    });
}

Any idea of what is wrong?

kthorngren

I'm guessing this is the code in question:

            events: {
                load: function(event) {
                    var total = 0; // get total of data
                    for (var i = 0, len = this.series[0].yData.length; i < len; i++) {
                        total += this.series[0].yData[i];
                    }
                    var text = this.renderer.text(
                        'Total: ' + total,
                        this.plotLeft,
                        this.plotTop - 20
                    ).attr({
                        zIndex: 5
                    }).add() // write it to the upper left hand corner              }
                }
            },

Doesn't look like there is anything Datatables specific in the code or question. You might be getting the data from Datatables but the question is specific to Highcharts. I would first start by debugging the function to find out what this.series[0] contains. From there you should be able to determine what you need to use to get the data total. You will need to refer to Highcharts docs, the Highcharts forum and/or Stack Overflow for Highcharts specific questions.

Maybe load isn't the correct event depending on when the cart is initially created. Maybe you need another event like redraw.

Kevin

carrarachristophe

Hi Kevin,
Thanks for your message.

I guess this is the part that was missing in my code above, and that is drawing the Highchart based on the Datatable:

    // On each draw, update the data in the chart
    table.on('draw', function () {
        chart_type.series[0].setData(chartData_type(table));
    });

I activated the Highcharts debugger but not getting any error message.

allan

Please link to a test case showing the issue so we can take a look.

Allan

carrarachristophe

Dear Kevin and Allan,

Thanks a lot for your help.
I found this interesting post and was able to solve my issue with below code.

    var chart_type = Highcharts.chart("container_type", {
        chart: {
            type: 'pie',
            events: {
                render: function() {
                let series = this.series
                let sum = 0
                for(let i = 0; i < series.length; i++) {
                    if(series[i].visible){
                    for(let j = 0; j < series[i].data.length; j++) {
                        sum += series[i].data[j].y
                    }
                  }
                }
                this.setTitle({text: Highcharts.numberFormat(sum, 0,","," ") + " prochains achats par type"}, false, false) 
                }
            }
        },
        title: {
            align: 'center',
            style: {
                font: '24px "Helvetica Neue", Helvetica, Arial, sans-serif'
            }
        },

Basically it includes render (no need of load or redraw) and the setTitle function, and only styling in the title part as the title is defined in the chart/events part.