Backend API
        
    import React, { useCallback, useState } from 'react';
import { unified } from "unified";
import remarkParse from "remark-parse";
import remarkRehype from "remark-rehype";
import remarkStringify from "remark-stringify";
import rehypeParse from "rehype-parse";
import rehypeRemark from "rehype-remark";
import rehypeStringify from "rehype-stringify";
import HtmlEditor, { Toolbar, Item } from 'devextreme-react/html-editor';
import { markup } from './data.ts';
const headerValues = [false, 1, 2, 3, 4, 5];
const headerOptions = {
  inputAttr: {
    'aria-label': 'Header',
  },
};
const converter = {
  toHtml(value) {
    const result = unified()
      .use(remarkParse)
      .use(remarkRehype)
      .use(rehypeStringify)
      .processSync(value)
      .toString();
    return result;
  },
  fromHtml(value) {
    const result = unified()
      .use(rehypeParse)
      .use(rehypeRemark)
      .use(remarkStringify)
      .processSync(value)
      .toString();
    return result;
  },
};
export default function App() {
  const [valueContent, setValueContent] = useState(markup);
  const valueChanged = useCallback((e: { value?: string; }) => {
    setValueContent(e.value);
  }, [setValueContent]);
  return (
    <div className="widget-container">
      <HtmlEditor
        converter={converter}
        height={300}
        defaultValue={valueContent}
        onValueChanged={valueChanged}
      >
        <Toolbar>
          <Item name="undo" />
          <Item name="redo" />
          <Item name="separator" />
          <Item name="bold" />
          <Item name="italic" />
          <Item name="separator" />
          <Item name="header" acceptedValues={headerValues} options={headerOptions} />
          <Item name="separator" />
          <Item name="orderedList" />
          <Item name="bulletList" />
        </Toolbar>
      </HtmlEditor>
      <div className="options">
        <div className="value-title">
          Markdown Preview
        </div>
        <div className="value-content" tabIndex={0}>
          {valueContent}
        </div>
      </div>
    </div>
  );
}
    
    import React, { useCallback, useState } from 'react';
import { unified } from 'unified';
import remarkParse from 'remark-parse';
import remarkRehype from 'remark-rehype';
import remarkStringify from 'remark-stringify';
import rehypeParse from 'rehype-parse';
import rehypeRemark from 'rehype-remark';
import rehypeStringify from 'rehype-stringify';
import HtmlEditor, { Toolbar, Item } from 'devextreme-react/html-editor';
import { markup } from './data.js';
const headerValues = [false, 1, 2, 3, 4, 5];
const headerOptions = {
  inputAttr: {
    'aria-label': 'Header',
  },
};
const converter = {
  toHtml(value) {
    const result = unified()
      .use(remarkParse)
      .use(remarkRehype)
      .use(rehypeStringify)
      .processSync(value)
      .toString();
    return result;
  },
  fromHtml(value) {
    const result = unified()
      .use(rehypeParse)
      .use(rehypeRemark)
      .use(remarkStringify)
      .processSync(value)
      .toString();
    return result;
  },
};
export default function App() {
  const [valueContent, setValueContent] = useState(markup);
  const valueChanged = useCallback(
    (e) => {
      setValueContent(e.value);
    },
    [setValueContent],
  );
  return (
    <div className="widget-container">
      <HtmlEditor
        converter={converter}
        height={300}
        defaultValue={valueContent}
        onValueChanged={valueChanged}
      >
        <Toolbar>
          <Item name="undo" />
          <Item name="redo" />
          <Item name="separator" />
          <Item name="bold" />
          <Item name="italic" />
          <Item name="separator" />
          <Item
            name="header"
            acceptedValues={headerValues}
            options={headerOptions}
          />
          <Item name="separator" />
          <Item name="orderedList" />
          <Item name="bulletList" />
        </Toolbar>
      </HtmlEditor>
      <div className="options">
        <div className="value-title">Markdown Preview</div>
        <div
          className="value-content"
          tabIndex={0}
        >
          {valueContent}
        </div>
      </div>
    </div>
  );
}
    
    import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.tsx';
ReactDOM.render(
  <App />,
  document.getElementById('app'),
);
    
    export const markup = `##  Formatted Text Editor (HTML Editor)
Lists:
1. Use numbers followed by a period for an ordered list.
1. Use a single asterisk for a bullet list.
Formats:
* Enclose a word in single asterisks for *italic*.
* Enclose a word in double asterisks for **bold**.
`;
    
    window.exports = window.exports || {};
window.config = {
  transpiler: 'ts',
  typescriptOptions: {
    module: 'system',
    emitDecoratorMetadata: true,
    experimentalDecorators: true,
    jsx: 'react',
  },
  meta: {
    'react': {
      'esModule': true,
    },
    'typescript': {
      'exports': 'ts',
    },
    'devextreme/time_zone_utils.js': {
      'esModule': true,
    },
    'devextreme/localization.js': {
      'esModule': true,
    },
    'devextreme/viz/palette.js': {
      'esModule': true,
    },
    'openai': {
      'esModule': true,
    },
  },
  paths: {
    'npm:': 'https://cdn.jsdelivr.net/npm/',
    'bundles:': '../../../../bundles/',
    'externals:': '../../../../bundles/externals/',
  },
  defaultExtension: 'js',
  map: {
    'ts': 'npm:plugin-typescript@8.0.0/lib/plugin.js',
    'typescript': 'npm:typescript@4.2.4/lib/typescript.js',
    'jszip': 'npm:jszip@3.10.1/dist/jszip.min.js',
    'react': 'npm:react@17.0.2/umd/react.development.js',
    'react-dom': 'npm:react-dom@17.0.2/umd/react-dom.development.js',
    'prop-types': 'npm:prop-types/prop-types.js',
    'rrule': 'npm:rrule@2.6.4/dist/es5/rrule.js',
    'luxon': 'npm:luxon@3.4.4/build/global/luxon.min.js',
    'es6-object-assign': 'npm:es6-object-assign',
    'devextreme': 'npm:devextreme@link:../../packages/devextreme/artifacts/npm/devextreme/cjs',
    'devextreme-react': 'npm:devextreme-react@link:../../packages/devextreme-react/npm/cjs',
    'unified': 'externals:unified/unified.bundle.js',
    'remark-parse': 'externals:unified/remark-parse.bundle.js',
    'remark-rehype': 'externals:unified/remark-rehype.bundle.js',
    'remark-stringify': 'externals:unified/remark-stringify.bundle.js',
    'rehype-parse': 'externals:unified/rehype-parse.bundle.js',
    'rehype-remark': 'externals:unified/rehype-remark.bundle.js',
    'rehype-stringify': 'externals:unified/rehype-stringify.bundle.js',
    'rehype-minify-whitespace': 'externals:unified/rehype-minify-whitespace.bundle.js',
    'devextreme-quill': 'npm:devextreme-quill@1.7.6/dist/dx-quill.min.js',
    'devexpress-diagram': 'npm:devexpress-diagram@2.2.24/dist/dx-diagram.js',
    'devexpress-gantt': 'npm:devexpress-gantt@4.1.64/dist/dx-gantt.js',
    'inferno': 'npm:inferno@8.2.3/dist/inferno.min.js',
    'inferno-compat': 'npm:inferno-compat/dist/inferno-compat.min.js',
    'inferno-create-element': 'npm:inferno-create-element@8.2.3/dist/inferno-create-element.min.js',
    'inferno-dom': 'npm:inferno-dom/dist/inferno-dom.min.js',
    'inferno-hydrate': 'npm:inferno-hydrate/dist/inferno-hydrate.min.js',
    'inferno-clone-vnode': 'npm:inferno-clone-vnode/dist/inferno-clone-vnode.min.js',
    'inferno-create-class': 'npm:inferno-create-class/dist/inferno-create-class.min.js',
    'inferno-extras': 'npm:inferno-extras/dist/inferno-extras.min.js',
    '@preact/signals-core': 'npm:@preact/signals-core@1.8.0/dist/signals-core.min.js',
    'devextreme-cldr-data': 'npm:devextreme-cldr-data@1.0.3',
    // SystemJS plugins
    'plugin-babel': 'npm:systemjs-plugin-babel@0.0.25/plugin-babel.js',
    'systemjs-babel-build': 'npm:systemjs-plugin-babel@0.0.25/systemjs-babel-browser.js',
    // Prettier
    'prettier/standalone': 'npm:prettier@2.8.8/standalone.js',
    'prettier/parser-html': 'npm:prettier@2.8.8/parser-html.js',
  },
  packages: {
    'devextreme': {
      defaultExtension: 'js',
    },
    'devextreme-react': {
      main: 'index.js',
    },
    'devextreme-react/common': {
      main: 'index.js',
    },
    'devextreme/events/utils': {
      main: 'index',
    },
    'devextreme/common/core/events/utils': {
      main: 'index',
    },
    'devextreme/localization/messages': {
      format: 'json',
      defaultExtension: 'json',
    },
    'devextreme/events': {
      main: 'index',
    },
    'es6-object-assign': {
      main: './index.js',
      defaultExtension: 'js',
    },
  },
  packageConfigPaths: [
    'npm:@devextreme/*/package.json',
  ],
  babelOptions: {
    sourceMaps: false,
    stage0: true,
    react: true,
  },
};
System.config(window.config);
// eslint-disable-next-line
const useTgzInCSB = ['openai'];
let packagesInfo = {
 "rehype-minify-whitespace": {
  "version": "5.0.1"
 },
 "rehype-parse": {
  "version": "8.0.5"
 },
 "rehype-remark": {
  "version": "9.0.0"
 },
 "rehype-stringify": {
  "version": "9.0.4"
 },
 "remark-parse": {
  "version": "10.0.2"
 },
 "remark-rehype": {
  "version": "10.1.0"
 },
 "remark-stringify": {
  "version": "10.0.3"
 },
 "unified": {
  "version": "10.1.2"
 }
};
    
    import React from 'react';
import ReactDOM from 'react-dom';
import App from './App.js';
ReactDOM.render(<App />, document.getElementById('app'));
    
    export const markup = `##  Formatted Text Editor (HTML Editor)
Lists:
1. Use numbers followed by a period for an ordered list.
1. Use a single asterisk for a bullet list.
Formats:
* Enclose a word in single asterisks for *italic*.
* Enclose a word in double asterisks for **bold**.
`;
    
    <!DOCTYPE html>
<html lang="en">
  <head>
    <title>DevExtreme Demo</title>
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0" />
    <link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/25.1.6/css/dx.light.css" />
    <link rel="stylesheet" type="text/css" href="styles.css" />
    <script src="https://cdn.jsdelivr.net/npm/core-js@2.6.12/client/shim.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/systemjs@0.21.3/dist/system.js"></script>
    <script type="text/javascript" src="config.js"></script>
    <script type="text/javascript">
      System.import("./index.tsx");
    </script>
  </head>
  <body class="dx-viewport">
    <div class="demo-container">
      <div id="app"></div>
    </div>
  </body>
</html>
    
    .dx-htmleditor-content img {
  vertical-align: middle;
  padding-right: 10px;
  margin-bottom: 22px;
}
.value-title {
  font-size: var(--dx-font-size-sm);
  font-weight: 500;
}
.value-content {
  margin-top: 20px;
  overflow: auto;
  height: 210px;
  white-space: pre-wrap;
  border: 1px solid var(--dx-color-border);
  padding: 16px;
  background-color: var(--dx-color-main-bg);
}
.options {
  margin-top: 20px;
  padding: 20px;
  background-color: rgba(191, 191, 191, 0.15);
  box-sizing: border-box;
  width: 100%;
}