Donut title doesn't display if datasets are empty initially

[sdarnell]

I have a donut chart that I populate from a reactive source, and therefore I don't have any data to hand when the initial c3.generate is called. Some time later I add the data.

  var chart = c3.generate({
    size: { width: 300, height: 300 },
    data: {
      columns: [
      ],
      type : 'donut',
    },
    donut: {
      title: "Owner"
    }
  });

I add the data later with:

    chart.load({ columns: _.pairs(_.countBy(issues, 'Owner')) });

The problem seems to be that generation of the title uses:

            // Define g for arc chart area
            main.select('.' + CLASS.chart).append("g")
                .attr("class", CLASS.chartArcs)
                .attr("transform", translate.arc)
              .append('text')
                .attr('class', CLASS.chartArcsTitle)
                .style("text-anchor", "middle")
                .text(getArcTitle());
... with ...
        function getArcTitle() {
            return hasDonutType(c3.data.targets) ? __donut_title : "";
        }

but during init the hasDonutType() returns false because c3.data.targets is empty, and the title doesn't seem to be regenerated when adding data sources.

If this isn't a bug, what is the preferred way to do this lazy initialisation?
I did try having a dummy data source called 'Loading...' which I remove afterwards, but that felt a bit clunky.
I could also keep a separate flag to indicate that I should generate things - but this is also clunky as I would rather keep my data updates completely independent of the chart configuration.

[sdarnell]

A simple fix seems to be to remove the check:

        function getArcTitle() {
            return __donut_title;
//            return hasDonutType(c3.data.targets) ? __donut_title : "";
        }

The title is hidden when switching to other types of chart, e.g. chart.toPie() so it displays OK.

[masayuki0812]

Hi @sdarnell , Thank you for reporting. I'll check and fix this.

[masayuki0812]

Hi @sdarnell , I think this has been fixed in the latest version 0.1.42. Could you try that version? Thank you.