Chartjs-Show label for every data point in line chart

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It is possible to do this with chart.js using the plugins API. Here is an example of a plugin that I use in production to show labels for all data points when the chart renders.

Note, I currently only use bar charts so you might have to tweak some things for line charts. As you will also see, I added a new options property called showDatapoints that I can set to true in order to use the plugin on certain graphs.

Chart.plugins.register({
  afterDraw: function(chartInstance) {
    if (chartInstance.config.options.showDatapoints) {
      var helpers = Chart.helpers;
      var ctx = chartInstance.chart.ctx;
      var fontColor = helpers.getValueOrDefault(chartInstance.config.options.showDatapoints.fontColor, chartInstance.config.options.defaultFontColor);

      // render the value of the chart above the bar
      ctx.font = Chart.helpers.fontString(Chart.defaults.global.defaultFontSize, 'normal', Chart.defaults.global.defaultFontFamily);
      ctx.textAlign = 'center';
      ctx.textBaseline = 'bottom';
      ctx.fillStyle = fontColor;

      chartInstance.data.datasets.forEach(function (dataset) {
        for (var i = 0; i < dataset.data.length; i++) {
          var model = dataset._meta[Object.keys(dataset._meta)[0]].data[i]._model;
          var scaleMax = dataset._meta[Object.keys(dataset._meta)[0]].data[i]._yScale.maxHeight;
          var yPos = (scaleMax - model.y) / scaleMax >= 0.93 ? model.y + 20 : model.y - 5;
          ctx.fillText(dataset.data[i], model.x, yPos);
        }
      });
    }
  }
});

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