Mirage-MDE

A modern, feature-rich Markdown editor built on top of CodeMirror 6 and Lit Element. Mirage-MDE provides a complete markdown editing experience with live preview, syntax highlighting, and extensive customization options.

Features

Editor Features

• CodeMirror 6 based editing with syntax highlighting
• Live Preview with side-by-side or fullscreen modes
• Toolbar with common markdown formatting actions
• Status Bar with cursor position, word count, and line count
• Keyboard Shortcuts for all major operations
• Autosave functionality with configurable intervals
• Image Upload support with drag & drop
• Fullscreen Mode for distraction-free editing

Markdown Support

• GitHub Flavored Markdown (GFM)
• Extended Tables with advanced formatting
• Syntax Highlighting for code blocks
• Task Lists with checkboxes
• Heading IDs for anchor links
• Link Mangling for security
• Custom Preprocessors for content transformation

Customization

• Theming with CSS custom properties
• Custom Toolbar actions and buttons
• Custom Status Bar items
• Plugin System for extensions
• Configurable Options for all behaviors

Installation

npm install @arcmantle/mirage-mde

pnpm add @arcmantle/mirage-mde

yarn add @arcmantle/mirage-mde

Basic Usage

HTML

<mirage-mde value="# Hello World"></mirage-mde>

TypeScript

import '@arcmantle/mirage-mde';

const editor = document.querySelector('mirage-mde');
editor.value = '# Hello World\n\nThis is **bold** text.';

With Options

const editor = document.querySelector('mirage-mde');
editor.options = {
  lineNumbers: true,
  lineWrapping: true,
  autosave: {
    enabled: true,
    uniqueId: 'my-editor',
    delay: 1000
  },
  uploadImage: true,
  toolbar: ['bold', 'italic', 'heading', '|', 'quote', 'code', 'link']
};

Configuration Options

Basic Options

• lineNumbers (boolean): Show line numbers in editor
• lineWrapping (boolean): Enable line wrapping
• tabSize (number): Tab size in spaces (default: 3)
• placeholder (string): Placeholder text for empty editor
• autofocus (boolean): Focus editor on load
• direction ('ltr' | 'rtl'): Text direction

Rendering Options

• singleLineBreaks (boolean): Convert single line breaks to <br>
• codeSyntaxHighlighting (boolean): Enable syntax highlighting in code blocks
• sanitizerFunction (function): Custom HTML sanitizer
• previewRender (function): Custom preview renderer

Toolbar Configuration

toolbar: [
  'bold', 'italic', 'strikethrough', '|',
  'heading', 'heading-smaller', 'heading-bigger', '|',
  'code', 'quote', 'unordered-list', 'ordered-list', '|',
  'link', 'image', 'table', 'horizontal-rule', '|',
  'preview', 'side-by-side', 'fullscreen', '|',
  'guide'
]

Status Bar Configuration

statusbar: [
  'autosave', 'lines', 'words', 'cursor'
]

Image Upload

uploadImage: true,
imageMaxSize: 2097152, // 2MB
imageAccept: 'image/png, image/jpeg, image/gif, image/avif',
imageUploadFunction: (file, onSuccess, onError) => {
  // Custom upload logic
  uploadToServer(file)
    .then(url => onSuccess(url))
    .catch(error => onError(error.message));
}

Autosave

autosave: {
  enabled: true,
  uniqueId: 'my-editor-content',
  delay: 1000,
  submit_delay: 5000,
  text: 'Autosaved: ',
  timeFormat: {
    locale: 'en-US',
    format: {
      hour: '2-digit',
      minute: '2-digit'
    }
  }
}

API Reference

MirageMDEElement

Properties

• value: string - The markdown content
• options: Options - Editor configuration

Methods

• editor.value() - Get current content
• editor.value(content) - Set content
• editor.action(actionName) - Execute toolbar action

Events

• change - Fired when content changes

Keyboard Shortcuts

| Action | Shortcut | |--------|----------| | Bold | Ctrl+B | | Italic | Ctrl+I | | Link | Ctrl+K | | Image | Ctrl+Alt+I | | Code Block | Ctrl+Alt+C | | Quote | Ctrl+' | | Unordered List | Ctrl+L | | Ordered List | Ctrl+Alt+L | | Heading | Ctrl+H | | Horizontal Rule | Ctrl+R | | Preview | Ctrl+P | | Side by Side | F9 | | Fullscreen | F11 | | Table | Ctrl+Alt+T | | Toggle Checkbox | Ctrl+D | | Undo | Ctrl+Z | | Redo | Ctrl+Y |

Theming

Mirage-MDE supports extensive theming through CSS custom properties:

mirage-mde {
  --mmde-border: 2px solid #333;
  --mmde-color: #fff;
  --mmde-background-color: #1a1a1a;
  --mmde-toolbar-bg: #2d2d2d;
  --mmde-editor-bg: #1e1e1e;
  --mmde-editor-family: 'Fira Code', monospace;
  --mmde-preview-family: 'Georgia', serif;
}

Advanced Usage

Custom Toolbar Actions

const customAction = {
  name: 'my-action',
  type: 'button',
  title: 'My Custom Action',
  iconUrl: 'path/to/icon.svg',
  action: (view, scope) => {
    // Custom action logic
    const selection = view.state.selection.main;
    const text = view.state.doc.sliceString(selection.from, selection.to);
    // Transform text and update editor
  }
};

editor.options = {
  toolbar: ['bold', 'italic', 'my-action'],
  toolbarActions: [customAction]
};

Custom Status Bar Items

const customStatus = {
  name: 'my-status',
  template: (item) => `<div>Custom: ${item.value}</div>`,
  onUpdate: (item, update) => {
    item.value = 'some value';
  }
};

editor.options = {
  statusbar: ['lines', 'words', 'my-status'],
  statusbarStatuses: [customStatus]
};

Custom Preprocessors

editor.options = {
  renderingConfig: {
    preprocessor: [
      {
        regexp: /\{\{([^}]+)\}\}/g,
        replacer: (match, content) => {
          // Transform template syntax
          return `<span class="template">${content}</span>`;
        }
      }
    ]
  }
};

Dependencies

• @codemirror/* - Core editing functionality
• marked - Markdown parsing and rendering
• highlight.js - Code syntax highlighting
• lit - Web components framework

Browser Support

• Chrome/Edge 88+
• Firefox 84+
• Safari 14+

License

Apache-2.0

Contributing

This is part of the Arcmantle Weave component library. Please refer to the main repository for contribution guidelines.