Plugin Kanban - Lazy-Loaded Kanban Board

A lazy-loaded kanban board component for Object UI based on @dnd-kit for drag-and-drop functionality.

Features

• Internal Lazy Loading: @dnd-kit libraries are loaded on-demand using React.lazy() and Suspense
• Zero Configuration: Just import the package and use type: 'kanban' in your schema
• Automatic Registration: Components auto-register with the ComponentRegistry
• Skeleton Loading: Shows a skeleton while @dnd-kit loads
• Drag and Drop: Full drag-and-drop support for cards between columns
• Column Limits: Set maximum card limits per column
• Customizable: Badge support, custom styling, and callbacks

Installation

pnpm add @object-ui/plugin-kanban

Usage

Automatic Registration (Side-Effect Import)

// In your app entry point (e.g., App.tsx or main.tsx)
import '@object-ui/plugin-kanban';

// Now you can use kanban type in your schemas
const schema = {
  type: 'kanban',
  columns: [
    {
      id: 'todo',
      title: 'To Do',
      cards: [
        { id: '1', title: 'Task 1', description: 'Description' }
      ]
    },
    {
      id: 'done',
      title: 'Done',
      cards: []
    }
  ]
};

Manual Integration

import { kanbanComponents } from '@object-ui/plugin-kanban';
import { ComponentRegistry } from '@object-ui/core';

// Manually register if needed
Object.entries(kanbanComponents).forEach(([type, component]) => {
  ComponentRegistry.register(type, component);
});

TypeScript Support

The plugin exports TypeScript types for full type safety:

import type { KanbanSchema, KanbanCard, KanbanColumn } from '@object-ui/plugin-kanban';

const card: KanbanCard = {
  id: 'task-1',
  title: 'My Task',
  description: 'Task description',
  badges: [
    { label: 'High Priority', variant: 'destructive' }
  ]
};

const column: KanbanColumn = {
  id: 'todo',
  title: 'To Do',
  cards: [card],
  limit: 5
};

const schema: KanbanSchema = {
  type: 'kanban',
  columns: [column]
};

Schema API

{
  type: 'kanban',
  columns?: KanbanColumn[],           // Array of columns
  onCardMove?: (cardId, fromColumnId, toColumnId, newIndex) => void,
  className?: string                  // Tailwind classes
}

// Column structure
interface KanbanColumn {
  id: string;
  title: string;
  cards: KanbanCard[];
  limit?: number;                     // Maximum cards allowed
  className?: string;
}

// Card structure
interface KanbanCard {
  id: string;
  title: string;
  description?: string;
  badges?: Array<{
    label: string;
    variant?: 'default' | 'secondary' | 'destructive' | 'outline';
  }>;
}

Features

• Drag and Drop: Drag cards between columns or reorder within a column
• Column Limits: Set maximum card limits and get visual feedback when full
• Card Badges: Add colored badges to cards for status/priority
• Responsive: Horizontal scrolling for many columns
• Accessible: Built on @dnd-kit with keyboard navigation support

Lazy Loading Architecture

The plugin uses a two-file pattern for optimal code splitting:

1. KanbanImpl.tsx: Contains the actual @dnd-kit imports (heavy ~100-150 KB)
2. index.tsx: Entry point with React.lazy() wrapper (light)

When bundled, Vite automatically creates separate chunks:

• index.js (~200 bytes) - The entry point
• KanbanImpl-xxx.js (~100-150 KB) - The lazy-loaded implementation

The @dnd-kit libraries are only downloaded when a kanban component is actually rendered, not on initial page load.

Bundle Size Impact

By using lazy loading, the main application bundle stays lean:

• Without lazy loading: +100-150 KB on initial load
• With lazy loading: +0.19 KB on initial load, +100-150 KB only when kanban is rendered

This results in significantly faster initial page loads for applications that don't use kanban on every page.

Development

# Build the plugin
pnpm build

# The package will generate proper ESM and UMD builds with lazy loading preserved

Example with Callbacks

const schema = {
  type: 'kanban',
  columns: [...],
  onCardMove: (cardId, fromColumnId, toColumnId, newIndex) => {
    console.log(`Card ${cardId} moved from ${fromColumnId} to ${toColumnId} at index ${newIndex}`);
    // Update your backend or state here
  }
};