ant-design-vue/components/icon/IconFont.jsx

import Icon from './index';

const customCache = new Set();

export default function create(options) {
  const { scriptUrl } = options;

  /**
   * DOM API required.
   * Make sure in browser environment.
   * The Custom Icon will create a <script/>
   * that loads SVG symbols and insert the SVG Element into the document body.
   */
  if (
    typeof document !== 'undefined' &&
    typeof window !== 'undefined' &&
    typeof document.createElement === 'function' &&
    typeof scriptUrl === 'string' &&
    scriptUrl.length &&
    !customCache.has(scriptUrl)
  ) {
    const script = document.createElement('script');
    script.setAttribute('src', scriptUrl);
    script.setAttribute('data-namespace', scriptUrl);
    customCache.add(scriptUrl);
    document.body.appendChild(script);
  }

  const Iconfont = {
    functional: true,
    name: 'AIconfont',
    props: Icon.props,
    render(h, context) {
      const { props, slots, listeners, data } = context;
      const { type, ...restProps } = props;
      const slotsMap = slots();
      const children = slotsMap.default;
      // component > children > type
      let content = null;
      if (type) {
        content = <use {...{ attrs: { 'xlink:href': `#${type}` } }} />;
      }
      if (children) {
        content = children;
      }
      return <Icon {...{ ...data, props: restProps, on: listeners }}>{content}</Icon>;
    },
  };
  return Iconfont;
}