Change options of individual point in dataset

[igomonteiro]

Summarizing

Hi! I'm trying to change options of specific points in my dataset, but when I change the options of an individual point, the options of the other points also change, like they are sharing the options.
What can I do? The lib have some kinda method that update an individual element? An individual point?

The problem

First of all: English is not my native language, I hope you guys understand my question.
What i'm trying to do is a "one row gantt chart", to do that, I created five datasets, each representing one condition in the time, when the condition in time not happens, i set x and y to NaN, doing that chartjs dont draw a line, also spanGaps is not set to true. And to draw a bar insted of a line, I've setted the border width to 40.

The result is shown in the figure below.

Observing the figure, we see a lot of white gaps, those white gaps are lonely points, zooming the chart we note that (figure below).

What i've tried to to is: find every lonely point (checking if the previous and next points are null and if my current point isn't null), the reason for the y===0 is because all points of dataset are constant = 0, the only axis that change is X (time type). Then I set the individual point to be a vertical line of radius/hoverRadius equals to 20, with this the point becomes the height of the "fake bar". Below is my piece of code.

beforeDatasetsDraw(chart, args, options) {
  const { datasets } = chart.data;
  datasets.forEach((dataset, index, arr) => {
    if (dataset.yAxisID === 'ganttAxis') {
      const meta = chart.getDatasetMeta(index);
      if (meta.type === null) return;

      meta._parsed.forEach((parsed, index, array) => {
        if (index > 0 && index < array.length - 1) {
          const prevPoint = array[index - 1];
          const nextPoint = array[index + 1];

          // check if point in lonely
          if (!prevPoint.x && !prevPoint.y && !nextPoint.x && !nextPoint.y
            && parsed.x > 0 && parsed.y === 0) {

            meta.dataset.points[index].options.pointStyle = 'line';
            meta.dataset.points[index].options.rotation = 90;
            meta.dataset.points[index].options.radius = 20;
            meta.dataset.points[index].options.hoverRadius = 20;
          }
        }
      })
    }
  })
}

Doing that, the WHOLE dataset points options changed, I've noticed this after log the dataset again or just seeing the chart result:

I also tested the code fragment below to check if changing only one point, the whole dataset points changes, and they did.

meta.dataset.points[0].options.pointStyle = 'line';
meta.dataset.points[0].options.rotation = 90;
meta.dataset.points[0].options.radius = 20;
meta.dataset.points[0].options.hoverRadius = 20;