Rocket.Chat Markdown Tables

A Rocket.Chat App that renders markdown tables beautifully - either as SVG images or ASCII art.

Features

• Three rendering modes:
  • Cards (SVG) - Beautiful graphical tables, perfect for mobile
  • Unicode - Box-drawing characters (┌─┬─┐)
  • ASCII - Classic style (+, -, |)
• Paste from Excel/Sheets - Tab-separated data is automatically converted to tables
• Clickable links - URLs in tables are extracted and shown as clickable links below
• /tableprefs command - Users can customize their own display preferences
• Multilingual - Help text in 11 languages (auto-detect or admin-configured)
• Parses GitHub Flavored Markdown (GFM) tables
• Supports column alignment (left, center, right)
• Handles emojis correctly

Installation

Quick Install (Recommended)

1. Download the latest release from Releases

2. Enable Apps in Rocket.Chat:

   • Log in as administrator
   • Go to Administration (gear icon) → Settings → General → Apps
   • Set Enable the App Framework to True
   • Set Enable development mode to True (required for private apps)
   • Click Save changes

3. Install the App:

   • Go to Administration → Apps → Private Apps
   • Click Upload App
   • Select the downloaded .zip file
   • Click Install
   • When prompted, click Agree to accept permissions

4. Configure (optional):

   • Go to Administration → Apps → Markdown Tables → Settings
   • Choose table style: Cards (SVG), Unicode, or ASCII
   • Configure link display and language preferences

Build from Source

# Clone the repository
git clone https://github.com/bamsejon/rocketchat-markdown-tables.git
cd rocketchat-markdown-tables

# Install dependencies
npm install

# Build the app
npm run build

# The zip file will be created in dist/

Usage

Markdown Tables

Write standard markdown tables in your messages:

| Name    | Age | City      |
|---------|-----|-----------|
| Alice   | 30  | Stockholm |
| Bob     | 25  | Göteborg  |

Rendering Modes

Cards (SVG) - Clean graphical table, works great on mobile:

Unicode - Box-drawing characters:

┌─────────┬───────┬───────────┐
│ Name    │ Age   │ City      │
├─────────┼───────┼───────────┤
│ Alice   │ 30    │ Stockholm │
│ Bob     │ 25    │ Göteborg  │
└─────────┴───────┴───────────┘

ASCII - Classic style:

+---------+-------+-----------+
| Name    | Age   | City      |
+---------+-------+-----------+
| Alice   | 30    | Stockholm |
| Bob     | 25    | Göteborg  |
+---------+-------+-----------+

Paste from Excel/Spreadsheets

Copy cells from Excel, Google Sheets, or any spreadsheet and paste directly into Rocket.Chat. Tab-separated data is automatically converted!

Links in Tables

URLs in table cells are automatically extracted and displayed as clickable links below the table. Use /tableprefs links off to disable this.

User Preferences

Users can customize their own table display style, overriding the admin default:

/tableprefs style unicode  - Box-drawing characters (┌─┬─┐)
/tableprefs style ascii    - Classic style (+, -, |)
/tableprefs style cards    - SVG image (mobile-friendly)
/tableprefs style default  - Use admin default setting

/tableprefs links on       - Show links below tables
/tableprefs links off      - Hide links below tables

Run /tableprefs without arguments to see your current settings.

Column Alignment

The app supports standard GFM alignment syntax:

| Left-aligned | Center-aligned | Right-aligned |
|:-------------|:--------------:|--------------:|
| Left         |    Center      |         Right |

Configuration

Go to Administration → Apps → Markdown Tables → Settings

Setting	Description
Table Style	Cards (SVG), Unicode, or ASCII
Show links below table	Extract and display clickable links
Disable link previews	Prevent automatic URL previews
Default show links	Default setting for new users
Help text language	Auto-detect or select specific language

Requirements

• Rocket.Chat 6.0 or newer
• Apps Framework enabled
• Administrator access for installation

Troubleshooting

App doesn't appear after upload

• Make sure Enable development mode is set to True in Settings → General → Apps
• Try refreshing the page after enabling

Tables not rendering

• Check that the app is enabled in Administration → Apps → Private Apps
• Verify the app status shows "Enabled"
• Make sure your table has the separator row (e.g., |---|---|)

SVG tables not displaying

• Ensure you're using Cards mode in app settings
• Some older Rocket.Chat versions may not support data URL images

Changelog

v1.15.0

• User style override - Users can now choose their own table style via /tableprefs style ascii/unicode/cards
• Admin setting becomes the default, individual users can override with their preference
• Run /tableprefs style default to go back to using the admin setting

v1.14.0

• Fixed large table rendering - Tables with 3+ columns now render correctly
• Compressed SVG output - Uses CSS classes and shorter attributes to reduce base64 URL length
• Rocket.Chat compatibility - Fixes issue where long data URLs broke markdown parsing

v1.13.1

• Reverted nested markdown approach - Rocket.Chat doesn't support [![img](url)](link) syntax

v1.13.0

• Fixed click behavior - Tables now link to # when clicked, preventing the data URL popup
• Reverted attachment approach - Back to inline images for better rendering in desktop clients

v1.12.0

• Non-clickable tables - SVG tables rendered as attachments (reverted in v1.13.0 due to rendering issues in desktop client)

v1.11.0

• Column alignment in SVG - Left, center, and right alignment now works in Cards mode
• Fixed anchor links - Links like [Link](#) no longer cause rendering issues

v1.10.0

• Bold/italic/code support - Formatted text now renders correctly in SVG tables
• Text with **bold**, *italic*, or `code` displays with proper styling

v1.9.7

• Fixed SVG rendering when tables contain links
• Improved URL deduplication
• Links displayed before table image for proper rendering

v1.9.0

• Cards mode - SVG table rendering
• Clickable links - URLs extracted and shown below tables
• /tableprefs command - User preferences
• Multilingual help text - 11 languages supported

v1.8.0

• Extract and display clickable links below tables
• Support both markdown links and plain URLs
• Add setting to toggle link display

License

MIT

Author

bamsejon - https://github.com/bamsejon