uiwjs/react-md-editor

^{Special thanks to:}

SubList - Bill Reminder & Renewal Alerts

^{Using my app is also a way to support me:}

A simple markdown editor with preview, implemented with React.js and TypeScript. This React Component aims to provide a simple Markdown editor with syntax highlighting support. This is based on textarea encapsulation, so it does not depend on any modern code editors such as Acs, CodeMirror, Monaco etc.

Features

📑 Indent line or selected text by pressing tab key, with customizable indentation.
♻️ Based on textarea encapsulation, does not depend on any modern code editors.
🚧 Does not depend on the uiw component library.
🚘 Automatic list on new lines.
😻 GitHub flavored markdown support.
🌒 Support dark-mode/night-mode @v3.11.0+.
💡 Support next.js, Use examples in next.js.
Line/lines duplication (Ctrl+D) and movement (Alt+UpArrow/DownArrow) @v3.24.0+.

Quick Start

npm i @uiw/react-md-editor

yarn add @uiw/react-md-editor

Using

import React from "react";
import MDEditor from '@uiw/react-md-editor';

export default function App() {
  const [value, setValue] = React.useState("**Hello world!!!**");
  return (
    <div className="container">
      <MDEditor
        value={value}
        onChange={setValue}
      />
      <MDEditor.Markdown source={value} style={{ whiteSpace: 'pre-wrap' }} />
    </div>
  );
}

Headless Mode

The package exposes the necessary utilities to build a headless markdown editor with your own UI. This example creates a simple textarea that supports markdown keyboard shortcuts and correct handling of newlines.

import React from "react";
import { 
  handleKeyDown, 
  shortcuts, 
  TextAreaCommandOrchestrator,
  getCommands,
} from '@uiw/react-md-editor';

export default function App() {
  const [value, setValue] = React.useState("**Hello world!!!**");
  const textareaRef = React.useRef(null);
  const orchestratorRef = React.useRef(null);
  
  React.useEffect(() => {
    if (textareaRef.current) {
      orchestratorRef.current = new TextAreaCommandOrchestrator(textareaRef.current);
    }
  }, []);

  const onKeyDown = (e) => {
    handleKeyDown(e, 2, false);
    if (orchestratorRef.current) {
      shortcuts(e, getCommands(), orchestratorRef.current);
    }
  };

  return (
    <textarea
      ref={textareaRef}
      value={value}
      onChange={(e) => setValue(e.target.value)}
      onKeyDown={onKeyDown}
      style={{ width: '100%', height: 200, padding: 10 }}
    />
  );
}

Special Markdown syntax

Supports for CSS Style

Use HTML comments  to let Markdown support style customization.

## Title
<!--rehype:style=display: flex; height: 230px; align-items: center; justify-content: center; font-size: 38px;-->

Markdown Supports **Style**<!--rehype:style=color: red;-->

Ignore content display via HTML comments

Shown in GitHub readme, excluded in HTML.

# Hello World

<!--rehype:ignore:start-->Hello World<!--rehype:ignore:end-->

Good!

Output:

<h1>Hello World</h1>

<p>Good!</p>

Security

Please note markdown needs to be sanitized if you do not completely trust your authors. Otherwise, your app is vulnerable to XSS. This can be achieved by adding rehype-sanitize as a plugin.

import React from "react";
import MDEditor from '@uiw/react-md-editor';
import rehypeSanitize from "rehype-sanitize";

export default function App() {
  const [value, setValue] = React.useState(`**Hello world!!!** <IFRAME SRC=\"javascript:javascript:alert(window.origin);\"></IFRAME>`);
  return (
    <div className="container">
      <MDEditor
        value={value}
        onChange={setValue}
        previewOptions={{
          rehypePlugins: [[rehypeSanitize]],
        }}
      />
    </div>
  );
}

Remove Code Highlight

The following example can help you exclude code highlighting code from being included in the bundle. @uiw/react-md-editor/nohighlight component does not contain the ~~rehype-prism-plus~~ code highlighting package, ~~highlightEnable~~, ~~showLineNumbers~~ and ~~highlight line~~ functions will no longer work. (#586)

import React from "react";
import MDEditor from '@uiw/react-md-editor/nohighlight';

const code = `**Hello world!!!**
\`\`\`js
function demo() {}
\`\`\`
`

export default function App() {
  const [value, setValue] = React.useState(code);
  return (
    <div className="container">
      <MDEditor
        value={value}
        onChange={setValue}
      />
      <MDEditor.Markdown source={value} style={{ whiteSpace: 'pre-wrap' }} />
    </div>
  );
}

Common Code Highlight

Use @uiw/react-md-editor/common to keep syntax highlighting while only including the rehype-prism-plus/common language subset. This is a middle ground between the default full-language build and nohighlight.

import React from "react";
import MDEditor from '@uiw/react-md-editor/common';

const code = `**Hello world!!!**
\`\`\`js
function greet(name) {
  console.log('hello', name);
}
\`\`\`
`

export default function App() {
  const [value, setValue] = React.useState(code);
  return (
    <div className="container">
      <MDEditor
        value={value}
        onChange={setValue}
      />
      <MDEditor.Markdown source={value} style={{ whiteSpace: 'pre-wrap' }} />
    </div>
  );
}

Placeholder & maxLength

"Below is an example that sets the placeholder for the editor and defines the maximum input character length as 10 characters."

import React from "react";
import MDEditor from '@uiw/react-md-editor';

export default function App() {
  const [value, setValue] = React.useState("");
  return (
      <MDEditor
        value={value}
        onChange={setValue}
        textareaProps={{
          placeholder: 'Please enter Markdown text',
          maxLength: 10
        }}
      />
  );
}

Custom Toolbars

List commands select a word by default. Custom commands can pass 'line' to makeList to select the entire line instead

import MDEditor, { commands } from '@uiw/react-md-editor';

const lineListCommand = {
  ...commands.unorderedListCommand,
  execute: (state, api) => commands.makeList(state, api, '- ', 'line'),
};

// <MDEditor commands={[lineListCommand]} />

import React, { useState } from "react";
import MDEditor, { commands } from '@uiw/react-md-editor';

const title3 = {
  name: 'title3',
  keyCommand: 'title3',
  buttonProps: { 'aria-label': 'Insert title3' },
  icon: (
    <svg width="12" height="12" viewBox="0 0 520 520">
      <path fill="currentColor" d="M15.7083333,468 C7.03242448,468 0,462.030833 0,454.666667 L0,421.333333 C0,413.969167 7.03242448,408 15.7083333,408 L361.291667,408 C369.967576,408 377,413.969167 377,421.333333 L377,454.666667 C377,462.030833 369.967576,468 361.291667,468 L15.7083333,468 Z M21.6666667,366 C9.69989583,366 0,359.831861 0,352.222222 L0,317.777778 C0,310.168139 9.69989583,304 21.6666667,304 L498.333333,304 C510.300104,304 520,310.168139 520,317.777778 L520,352.222222 C520,359.831861 510.300104,366 498.333333,366 L21.6666667,366 Z M136.835938,64 L136.835937,126 L107.25,126 L107.25,251 L40.75,251 L40.75,126 L-5.68434189e-14,126 L-5.68434189e-14,64 L136.835938,64 Z M212,64 L212,251 L161.648438,251 L161.648438,64 L212,64 Z M378,64 L378,126 L343.25,126 L343.25,251 L281.75,251 L281.75,126 L238,126 L238,64 L378,64 Z M449.047619,189.550781 L520,189.550781 L520,251 L405,251 L405,64 L449.047619,64 L449.047619,189.550781 Z" />
    </svg>
  ),
  execute: (state, api) => {
    let modifyText = `### ${state.selectedText}\n`;
    if (!state.selectedText) {
      modifyText = `### `;
    }
    api.replaceSelection(modifyText);
  },
};

const title2 = {
  name: 'title2',
  keyCommand: 'title2',
  render: (command, disabled, executeCommand) => {
    return (
      <button 
        aria-label="Insert title2"
        disabled={disabled}
        onClick={(evn) => {
          // evn.stopPropagation();
          executeCommand(command, command.groupName)
        }}
      >
        <svg width="12" height="12" viewBox="0 0 520 520">
          <path fill="currentColor" d="M15.7083333,468 C7.03242448,468 0,462.030833 0,454.666667 L0,421.333333 C0,413.969167 7.03242448,408 15.7083333,408 L361.291667,408 C369.967576,408 377,413.969167 377,421.333333 L377,454.666667 C377,462.030833 369.967576,468 361.291667,468 L15.7083333,468 Z M21.6666667,366 C9.69989583,366 0,359.831861 0,352.222222 L0,317.777778 C0,310.168139 9.69989583,304 21.6666667,304 L498.333333,304 C510.300104,304 520,310.168139 520,317.777778 L520,352.222222 C520,359.831861 510.300104,366 498.333333,366 L21.6666667,366 Z M136.835938,64 L136.835937,126 L107.25,126 L107.25,251 L40.75,251 L40.75,126 L-5.68434189e-14,126 L-5.68434189e-14,64 L136.835938,64 Z M212,64 L212,251 L161.648438,251 L161.648438,64 L212,64 Z M378,64 L378,126 L343.25,126 L343.25,251 L281.75,251 L281.75,126 L238,126 L238,64 L378,64 Z M449.047619,189.550781 L520,189.550781 L520,251 L405,251 L405,64 L449.047619,64 L449.047619,189.550781 Z" />
        </svg>
      </button>
    )
  },
  execute: (state, api) => {
    let modifyText = `## ${state.selectedText}\n`;
    if (!state.selectedText) {
      modifyText = `## `;
    }
    api.replaceSelection(modifyText);
  },
}

function SubChildren({ close, execute, getState, textApi, dispatch }) {
  const [value, setValue] = useState('')
  const insert = () => {
    console.log('value:::', value)
    textApi.replaceSelection(value)
  }
  return (
    <div style={{ width: 120, padding: 10 }}>
      <div>My Custom Toolbar</div>
      <input type="text" onChange={(e) => setValue(e.target.value)} />
      <button
        type="button"
        onClick={() => {
          dispatch({ $value: '~~~~~~' })
          console.log('> execute: >>>>>', getState())
        }}
      >
        State
      </button>
      <button type="button" onClick={insert}>Insert</button>
      <button type="button" onClick={() => close()}>Close</button>
      <button type="button" onClick={() => execute()}>Execute</button>
    </div>
  );
}

const subChild = {
  name: 'update',
  groupName: 'update',
  icon: (
    <svg viewBox="0 0 1024 1024" width="12" height="12">
      <path fill="currentColor" d="M716.8 921.6a51.2 51.2 0 1 1 0 102.4H307.2a51.2 51.2 0 1 1 0-102.4h409.6zM475.8016 382.1568a51.2 51.2 0 0 1 72.3968 0l144.8448 144.8448a51.2 51.2 0 0 1-72.448 72.3968L563.2 541.952V768a51.2 51.2 0 0 1-45.2096 50.8416L512 819.2a51.2 51.2 0 0 1-51.2-51.2v-226.048l-57.3952 57.4464a51.2 51.2 0 0 1-67.584 4.2496l-4.864-4.2496a51.2 51.2 0 0 1 0-72.3968zM512 0c138.6496 0 253.4912 102.144 277.1456 236.288l10.752 0.3072C924.928 242.688 1024 348.0576 1024 476.5696 1024 608.9728 918.8352 716.8 788.48 716.8a51.2 51.2 0 1 1 0-102.4l8.3968-0.256C866.2016 609.6384 921.6 550.0416 921.6 476.5696c0-76.4416-59.904-137.8816-133.12-137.8816h-97.28v-51.2C691.2 184.9856 610.6624 102.4 512 102.4S332.8 184.9856 332.8 287.488v51.2H235.52c-73.216 0-133.12 61.44-133.12 137.8816C102.4 552.96 162.304 614.4 235.52 614.4l5.9904 0.3584A51.2 51.2 0 0 1 235.52 716.8C105.1648 716.8 0 608.9728 0 476.5696c0-132.1984 104.8064-239.872 234.8544-240.2816C258.5088 102.144 373.3504 0 512 0z" />
    </svg>
  ),
  children: (props) => <SubChildren {...props} />,
  execute: (state, api)  => {
    console.log('>>>>>>update>>>>>', state)
  },
  buttonProps: { 'aria-label': 'Insert title'}
}

export default function App() {
  const [value, setValue] = React.useState("Hello Markdown! `Tab` key uses default behavior");
  return (
    <div className="container">
      <MDEditor
        value={value}
        onChange={setValue}
        commands={[
          // Custom Toolbars
          title3, title2,
          commands.group([commands.title1, commands.title2, commands.title3, commands.title4, commands.title5, commands.title6], {
            name: 'title',
            groupName: 'title',
            buttonProps: { 'aria-label': 'Insert title'}
          }),
          commands.divider,
          commands.group([], subChild),
        ]}
      />
    </div>
  );
}

Customize the toolbar with commands and extraCommands props.

import React from "react";
import MDEditor, { commands } from '@uiw/react-md-editor';

export default function App() {
  const [value, setValue] = React.useState("Hello Markdown! `Tab` key uses default behavior");
  return (
    <div className="container">
      <MDEditor
        value={value}
        onChange={setValue}
        preview="edit"
        commands={[
          commands.codeEdit, commands.codePreview
        ]}
        extraCommands={[
          commands.group([commands.title1, commands.title2, commands.title3, commands.title4, commands.title5, commands.title6], {
            name: 'title',
            groupName: 'title',
            buttonProps: { 'aria-label': 'Insert title'}
          }),
          commands.divider,
          commands.group([], {
            name: 'update',
            groupName: 'update',
            icon: (
              <svg viewBox="0 0 1024 1024" width="12" height="12">
                <path fill="currentColor" d="M716.8 921.6a51.2 51.2 0 1 1 0 102.4H307.2a51.2 51.2 0 1 1 0-102.4h409.6zM475.8016 382.1568a51.2 51.2 0 0 1 72.3968 0l144.8448 144.8448a51.2 51.2 0 0 1-72.448 72.3968L563.2 541.952V768a51.2 51.2 0 0 1-45.2096 50.8416L512 819.2a51.2 51.2 0 0 1-51.2-51.2v-226.048l-57.3952 57.4464a51.2 51.2 0 0 1-67.584 4.2496l-4.864-4.2496a51.2 51.2 0 0 1 0-72.3968zM512 0c138.6496 0 253.4912 102.144 277.1456 236.288l10.752 0.3072C924.928 242.688 1024 348.0576 1024 476.5696 1024 608.9728 918.8352 716.8 788.48 716.8a51.2 51.2 0 1 1 0-102.4l8.3968-0.256C866.2016 609.6384 921.6 550.0416 921.6 476.5696c0-76.4416-59.904-137.8816-133.12-137.8816h-97.28v-51.2C691.2 184.9856 610.6624 102.4 512 102.4S332.8 184.9856 332.8 287.488v51.2H235.52c-73.216 0-133.12 61.44-133.12 137.8816C102.4 552.96 162.304 614.4 235.52 614.4l5.9904 0.3584A51.2 51.2 0 0 1 235.52 716.8C105.1648 716.8 0 608.9728 0 476.5696c0-132.1984 104.8064-239.872 234.8544-240.2816C258.5088 102.144 373.3504 0 512 0z" />
              </svg>
            ),
            children: ({ close, execute, getState, textApi }) => {
              return (
                <div style={{ width: 120, padding: 10 }}>
                  <div>My Custom Toolbar</div>
                  <button type="button" onClick={() => console.log('> execute: >>>>>', getState())}>State</button>
                  <button type="button" onClick={() => close()}>Close</button>
                  <button type="button" onClick={() => execute()}>Execute</button>
                </div>
              );
            },
            execute: (state, api)  => {
              console.log('>>>>>>update>>>>>', state)
            },
            buttonProps: { 'aria-label': 'Insert title'}
          }),
          commands.divider, commands.fullscreen
        ]}
      />
    </div>
  );
}

re-render toolbar element.

import React from "react";
import MDEditor, { commands } from '@uiw/react-md-editor';

export default function App() {
  const [value, setValue] = React.useState("Hello Markdown! `Tab` key uses default behavior");
  return (
    <div className="container">
      <MDEditor
        value={value}
        onChange={setValue}
        preview="edit"
        components={{
          toolbar: (command, disabled, executeCommand) => {
            if (command.keyCommand === 'code') {
              return (
                <button 
                  aria-label="Insert code"
                  disabled={disabled}
                  onClick={(evn) => {
                    evn.stopPropagation();
                    executeCommand(command, command.groupName)
                  }}
                >
                  Code
                </button>
              )
            }
          }
        }}
      />
    </div>
  );
}

Custom Preview Command Tool

import React, { useContext } from "react";
import MDEditor, { commands, EditorContext } from "@uiw/react-md-editor";

const Button = () => {
  const { preview, dispatch } = useContext(EditorContext);
  const click = () => {
    dispatch({
      preview: preview === "edit" ? "preview" : "edit"
    });
  };
  if (preview === "edit") {
    return (
      <svg width="12" height="12" viewBox="0 0 520 520" onClick={click}>
        <polygon
          fill="currentColor"
          points="0 71.293 0 122 319 122 319 397 0 397 0 449.707 372 449.413 372 71.293"
        />
        <polygon
          fill="currentColor"
          points="429 71.293 520 71.293 520 122 481 123 481 396 520 396 520 449.707 429 449.413"
        />
      </svg>
    );
  }
  return (
    <svg width="12" height="12" viewBox="0 0 520 520" onClick={click}>
      <polygon
        fill="currentColor"
        points="0 71.293 0 122 38.023 123 38.023 398 0 397 0 449.707 91.023 450.413 91.023 72.293"
      />
      <polygon
        fill="currentColor"
        points="148.023 72.293 520 71.293 520 122 200.023 124 200.023 397 520 396 520 449.707 148.023 450.413"
      />
    </svg>
  );
};

const codePreview = {
  name: "preview",
  keyCommand: "preview",
  value: "preview",
  icon: <Button />
};

const Disable = () => {
  const { preview, dispatch } = useContext(EditorContext);
  return (
    <button disabled={preview === "preview"}>
      <svg viewBox="0 0 16 16" width="12px" height="12px">
        <path
          d="M8 0C3.6 0 0 3.6 0 8s3.6 8 8 8 8-3.6 8-8-3.6-8-8-8Zm.9 13H7v-1.8h1.9V13Zm-.1-3.6v.5H7.1v-.6c.2-2.1 2-1.9 1.9-3.2.1-.7-.3-1.1-1-1.1-.8 0-1.2.7-1.2 1.6H5c0-1.7 1.2-3 2.9-3 2.3 0 3 1.4 3 2.3.1 2.3-1.9 2-2.1 3.5Z"
          fill="currentColor"
        />
      </svg>
    </button>
  )
}

const customButton = {
  name: "disable",
  keyCommand: "disable",
  value: "disable",
  icon: <Disable />
}

export default function App() {
  const [value, setValue] = React.useState("**Hello world!!!**");
  return (
    <div className="container">
      <div>The system automatically sets the theme</div>
      <MDEditor
        value={value}
        preview="edit"
        extraCommands={[codePreview, customButton, commands.fullscreen]}
        onChange={(val) => setValue(val)}
      />
    </div>
  );
}

Add Help Command Tool

import React, { useContext } from "react";
import MDEditor, { commands } from "@uiw/react-md-editor";

const help = {
  name: "help",
  keyCommand: "help",
  buttonProps: { "aria-label": "Insert help" },
  icon: (
    <svg viewBox="0 0 16 16" width="12px" height="12px">
      <path
        d="M8 0C3.6 0 0 3.6 0 8s3.6 8 8 8 8-3.6 8-8-3.6-8-8-8Zm.9 13H7v-1.8h1.9V13Zm-.1-3.6v.5H7.1v-.6c.2-2.1 2-1.9 1.9-3.2.1-.7-.3-1.1-1-1.1-.8 0-1.2.7-1.2 1.6H5c0-1.7 1.2-3 2.9-3 2.3 0 3 1.4 3 2.3.1 2.3-1.9 2-2.1 3.5Z"
        fill="currentColor"
      />
    </svg>
  ),
  execute: (state, api) => {
    window.open("https://www.markdownguide.org/basic-syntax/", "_blank");
  }
};

export default function App() {
  const [value, setValue] = React.useState("**Hello world!!!**");
  return (
    <MDEditor
      value={value}
      preview="edit"
      commands={[...commands.getCommands(), help]}
      onChange={(val) => setValue(val)}
    />
  );
}

Internationalization Example, You can refer to commands-cn for internationalization.

import React, { useContext } from "react";
import MDEditor, { commands } from "@uiw/react-md-editor";
import { getCommands, getExtraCommands } from "@uiw/react-md-editor/commands-cn";

export default function App() {
  const [value, setValue] = React.useState("**Hello world!!!**");
  return (
    <MDEditor
      value={value}
      preview="edit"
      commands={[...getCommands()]}
      extraCommands={[...getExtraCommands()]}
      onChange={(val) => setValue(val)}
    />
  );
}

Set to support editor only

import React, { useContext } from "react";
import MDEditor, { commands, EditorContext } from "@uiw/react-md-editor";

export default function App() {
  const [value, setValue] = React.useState("**Hello world!!!**");
  return (
    <div className="container">
      <MDEditor
        value={value}
        preview="edit"
        extraCommands={[commands.fullscreen]}
        onChange={(val) => setValue(val)}
      />
    </div>
  );
}

Editor Font Size

body .w-md-editor-text-pre > code,
body .w-md-editor-text-input {
  font-size: 23px !important;
  line-height: 24px !important;
}

Editor height adapts to text

The initial height can be adjusted through minHeight={100}. Dragbar will automatically expire. You can hide the drag button through visibleDragbar={false}

import React from "react";
import MDEditor from '@uiw/react-md-editor';

export default function App() {
  const [value, setValue] = React.useState("**Hello world!!!**");
  return (
    <div className="container">
      <MDEditor
        value={value}
        height="100%"
        // minHeight={50}
        visibleDragbar={false}
        onChange={setValue}
      />
    </div>
  );
}

Disallowed Elements

import React from "react";
import MDEditor from '@uiw/react-md-editor';

export default function App() {
  const [value, setValue] = React.useState("**Hello world!!!**  <style>body{display:none;}</style> ");
  return (
    <div className="container">
      <MDEditor
        value={value}
        height="100%"
        previewOptions={{
          disallowedElements: ['style'],
        }}
        visibleDragbar={false}
        onChange={setValue}
      />
    </div>
  );
}

Place the cursor at the end of the text

import React from "react";
import MDEditor from '@uiw/react-md-editor';

const textSample = `# Welcome to the Markdown Editor!

This is a sample of the **React Markdown Editor**.

## ✨ Features
- Real-time preview
- Custom styling support
- Code highlighting
- Auto focus at the end of the text

## 📦 Sample Code

\`\`\`javascript
function hello() {
  console.log("Hello, world!");
}
\`\`\`

## 🔗 Links

Visit [uiwjs/react-md-editor](https://github.com/uiwjs/react-md-editor) for more information.
`;

export default function App() {
  const [value, setValue] = React.useState(textSample);
  return (
    <div className="container">
      <MDEditor
        autoFocus={true}
        value={value}
        autoFocusEnd={true}
        visibleDragbar={false}
        onChange={setValue}
      />
    </div>
  );
}

Preview Markdown

import React from "react";
import MDEditor from '@uiw/react-md-editor';

export default function App() {
  return (
    <div className="container">
      <MDEditor.Markdown source="Hello Markdown!" />
    </div>
  );
}

Support Custom KaTeX Preview

KaTeX is a fast, easy-to-use JavaScript library for TeX math rendering on the web, We perform math rendering through KaTeX.

The following example is preview in CodeSandbox.

⚠️ Upgrade v2 to v3 d025430

npm install katex

import React from "react";
import MDEditor from '@uiw/react-md-editor';
import { getCodeString } from 'rehype-rewrite';
import katex from 'katex';
import 'katex/dist/katex.css';

const mdKaTeX = `This is to display the 
\`\$\$\c = \\pm\\sqrt{a^2 + b^2}\$\$\`
 in one line

\`\`\`KaTeX
c = \\pm\\sqrt{a^2 + b^2}
\`\`\`
`;

export default function App() {
  const [value, setValue] = React.useState(mdKaTeX);
  return (
    <MDEditor
      value={value}
      onChange={(val) => setValue(val)}
      previewOptions={{
        components: {
          code: ({ children = [], className, ...props }) => {
            if (typeof children === 'string' && /^\$\$(.*)\$\$/.test(children)) {
              const html = katex.renderToString(children.replace(/^\$\$(.*)\$\$/, '$1'), {
                throwOnError: false,
              });
              return <code dangerouslySetInnerHTML={{ __html: html }} style={{ background: 'transparent' }} />;
            }
            const code = props.node && props.node.children ? getCodeString(props.node.children) : children;
            if (
              typeof code === 'string' &&
              typeof className === 'string' &&
              /^language-katex/.test(className.toLocaleLowerCase())
            ) {
              const html = katex.renderToString(code, {
                throwOnError: false,
              });
              return <code style={{ fontSize: '150%' }} dangerouslySetInnerHTML={{ __html: html }} />;
            }
            return <code className={String(className)}>{children}</code>;
          },
        },
      }}
    />
  );
}

Markdown text to Image

import React, { useState } from "react";
import MDEditor, { commands, type ICommand, TextState, TextAreaTextApi } from "@uiw/react-md-editor";
import domToImage from "dom-to-image";

const textToImage: ICommand = {
  name: "Text To Image",
  keyCommand: "text2image",
  buttonProps: { "aria-label": "Insert title3" },
  icon: (
    <svg width="12" height="12" viewBox="0 0 20 20">
      <path fill="currentColor" d="M15 9c1.1 0 2-.9 2-2s-.9-2-2-2-2 .9-2 2 .9 2 2 2zm4-7H1c-.55 0-1 .45-1 1v14c0 .55.45 1 1 1h18c.55 0 1-.45 1-1V3c0-.55-.45-1-1-1zm-1 13l-6-5-2 2-4-5-4 8V4h16v11z" ></path>
    </svg>
  ),
  execute: (state: TextState, api: TextAreaTextApi) => {
    const dom = document.getElementsByClassName("gooooooooo")[0];
    if (dom) {
      domToImage.toJpeg(dom, {}).then((dataUrl) => {
        const link = document.createElement("a");
        link.download = "image.jpg";
        link.href = dataUrl;
        link.click();
      });
    }
  }
};

export default function App() {
  const [value, setValue] = useState('**Hello world!!!**');
  console.log('value::', value)
  return (
    <div className="container">
      <MDEditor
        className="gooooooooo"
        onChange={(newValue = "") => setValue(newValue)}
        value={value}
        commands={[
          textToImage,
          commands.divider
        ]}
      />
    </div>
  );
}

Support Custom Mermaid Preview

Using mermaid to generation of diagram and flowchart from text in a similar manner as markdown

npm install mermaid

import React, { useState, useRef, useEffect, Fragment, useCallback } from "react";
import MDEditor from "@uiw/react-md-editor";
import { getCodeString } from 'rehype-rewrite';
import mermaid from "mermaid";

const mdMermaid = `The following are some examples of the diagrams, charts and graphs that can be made using Mermaid and the Markdown-inspired text specific to it. 

\`\`\`mermaid
graph TD
A[Hard] -->|Text| B(Round)
B --> C{Decision}
C -->|One| D[Result 1]
C -->|Two| E[Result 2]
\`\`\`

\`\`\`mermaid
sequenceDiagram
Alice->>John: Hello John, how are you?
loop Healthcheck
    John->>John: Fight against hypochondria
end
Note right of John: Rational thoughts!
John-->>Alice: Great!
John->>Bob: How about you?
Bob-->>John: Jolly good!
\`\`\`
`;

const randomid = () => parseInt(String(Math.random() * 1e15), 10).toString(36);
const Code = ({ inline, children = [], className, ...props }) => {
  const demoid = useRef(`dome${randomid()}`);
  const [container, setContainer] = useState(null);
  const isMermaid =
    className && /^language-mermaid/.test(className.toLocaleLowerCase());
  const code = children
    ? getCodeString(props.node.children)
    : children[0] || "";

  useEffect(() => {
    if (container && isMermaid && demoid.current && code) {
      mermaid
        .render(demoid.current, code)
        .then(({ svg, bindFunctions }) => {
          container.innerHTML = svg;
          if (bindFunctions) {
            bindFunctions(container);
          }
        })
        .catch((error) => {
          console.log("error:", error);
        });
    }
  }, [container, isMermaid, code, demoid]);

  const refElement = useCallback((node) => {
    if (node !== null) {
      setContainer(node);
    }
  }, []);

  if (isMermaid) {
    return (
      <Fragment>
        <code id={demoid.current} style={{ display: "none" }} />
        <code className={className} ref={refElement} data-name="mermaid" />
      </Fragment>
    );
  }
  return <code className={className}>{children}</code>;
};

export default function App() {
  const [value, setValue] = useState(mdMermaid);
  return (
    <MDEditor
      onChange={(newValue = "") => setValue(newValue)}
      textareaProps={{
        placeholder: "Please enter Markdown text"
      }}
      height={500}
      value={value}
      previewOptions={{
        components: {
          code: Code
        }
      }}
    />
  );
}

Support Nextjs

Use examples in nextjs. #52 #224

npm install next-remove-imports
npm install @uiw/react-md-editor@v3.6.0

// next.config.js
const removeImports = require('next-remove-imports')();
module.exports = removeImports({});

import "@uiw/react-md-editor/markdown-editor.css";
import "@uiw/react-markdown-preview/markdown.css";
import dynamic from "next/dynamic";
import { useState } from "react";

import * as commands from "@uiw/react-md-editor/commands"

const MDEditor = dynamic(
  () => import("@uiw/react-md-editor"),
  { ssr: fals