Method getContext

src/core/core.datasetController.js:762–782

* @protected

(index, active, mode)

	 * @protected
	 */
  getContext(index, active, mode) {
    const dataset = this.getDataset();
    let context;
    if (index >= 0 && index < this._cachedMeta.data.length) {
      const element = this._cachedMeta.data[index];
      context = element.$context ||
        (element.$context = createDataContext(this.getContext(), index, element));
      context.parsed = this.getParsed(index);
      context.raw = dataset.data[index];
      context.index = context.dataIndex = index;
    } else {
      context = this.$context ||
        (this.$context = createDatasetContext(this.chart.getContext(), this.index));
      context.dataset = dataset;
      context.index = context.datasetIndex = this.index;
    }

    context.active = !!active;
    context.mode = mode;
    return context;
  }

  /**
	 * @param {string} [mode]