Converting Blocks to HTML

import "@blocknote/core/fonts/inter.css";
import { BlockNoteView } from "@blocknote/mantine";
import "@blocknote/mantine/style.css";
import { useCreateBlockNote } from "@blocknote/react";
import { useEffect, useState } from "react";

import "./styles.css";

export default function App() {
  // Stores the editor's contents as HTML.
  const [html, setHTML] = useState<string>("");

  // Creates a new editor instance with some initial content.
  const editor = useCreateBlockNote({
    initialContent: [
      {
        type: "paragraph",
        content: [
          "Hello, ",
          {
            type: "text",
            text: "world!",
            styles: {
              bold: true,
            },
          },
        ],
      },
    ],
  });

  const onChange = async () => {
    // Converts the editor's contents from Block objects to HTML and store to state.
    const html = await editor.blocksToHTMLLossy(editor.document);
    setHTML(html);
  };

  useEffect(() => {
    // on mount, trigger initial conversion of the initial content to html
    onChange();
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, []);

  // Renders the editor instance and HTML output.
  return (
    <div className="views">
      <div className="view-wrapper">
        <div className="view-label">Editor Input</div>
        <div className="view">
          <BlockNoteView editor={editor} onChange={onChange} />
        </div>
      </div>
      <div className="view-wrapper">
        <div className="view-label">HTML Output</div>
        <div className="view">
          <pre>
            <code>{html}</code>
          </pre>
        </div>
      </div>
    </div>
  );
}

.views {
  container-name: views;
  container-type: inline-size;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 8px;
  height: 100%;
  padding: 8px;
}

.view-wrapper {
  display: flex;
  flex-direction: column;
  height: calc(50% - 4px);
  width: 100%;
}

@container views (width > 1024px) {
  .view-wrapper {
    height: 100%;
    width: calc(50% - 4px);
  }
}

.view-label {
  color: #0090ff;
  display: flex;
  font-size: 12px;
  font-weight: bold;
  justify-content: space-between;
  margin-inline: 16px;
}

.view {
  border: solid #0090ff 1px;
  border-radius: 16px;
  flex: 1;
  height: 0;
  padding: 8px;
}

.view .bn-container {
  height: 100%;
  margin: 0;
  max-width: none;
  padding: 0;
}

.view .bn-editor {
  height: 100%;
  overflow: auto;
}

.view pre {
  background-color: #0090ff20;
  border-radius: 8px;
  flex: 1;
  height: 100%;
  margin: 0;
  overflow: auto;
  padding: 8px;
  white-space: pre-wrap;
}