3rd-ce-02.js

created() {
    this._el = undefined;
    this.chart = null;
    this.render();
    this.update(true);
  }
  update(newtype) {
    if (!newtype && this.chart) {
      return this.chart.update(this.data, this.options);
    }
    if (newtype && this.type && Chartist[this.type]) {
      this.chart = new Chartist[this.type](this, this.data, this.options);
    }
  }
  render() {
    this.html`<div class="ct-chart"></div>`;
    if (this._el) {
      this._el = this.querySelector(".ct-chart");
    }
  }