main.js

var getScriptPromisify = (src) => {
  return new Promise((resolve) => {
    $.getScript(src, resolve);
  });
};

(function () {
  const prepared = document.createElement("template");
  prepared.innerHTML = `
        <style>
        </style>
        <div id="root" style="width: 100%; height: 100%;">
        </div>
      `;
  class SamplePiePrepared extends HTMLElement {
    constructor() {
      super();

      this._shadowRoot = this.attachShadow({ mode: "open" });
      this._shadowRoot.appendChild(prepared.content.cloneNode(true));

      this._root = this._shadowRoot.getElementById("root");

      this._props = {};

      this.render();
    }

    onCustomWidgetResize(width, height) {
      this.render();
    }

    async render() {
      await getScriptPromisify(
        "https://cdn.bootcdn.net/ajax/libs/echarts/5.0.0/echarts.min.js"
      );

      const chart = echarts.init(this._root);
      const option = {
        tooltip: {
          trigger: "item",
        },
        legend: {
          top: "5%",
          left: "center",
        },
        series: [
          {
            name: "Access From",
            type: "pie",
            radius: ["40%", "70%"],
            avoidLabelOverlap: false,
            itemStyle: {
              borderRadius: 10,
              borderColor: "#fff",
              borderWidth: 2,
            },
            label: {
              show: false,
              position: "center",
            },
            emphasis: {
              label: {
                show: true,
                fontSize: "40",
                fontWeight: "bold",
              },
            },
            labelLine: {
              show: false,
            },
            data: [
              { value: 1048, name: "Search Engine" },
              { value: 735, name: "Direct" },
              { value: 580, name: "Email" },
              { value: 484, name: "Union Ads" },
              { value: 300, name: "Video Ads" },
            ],
          },
        ],
      };
      chart.setOption(option);
    }
  }

  customElements.define("github-sap-demo-sample-chart", SamplePiePrepared);
})();