# Lit Migration Summary ## Components Migrated (12 total) ### Layout Components (4) 1. **ct-vgroup** - Vertical group with gap management 2. **ct-hgroup** - Horizontal group with gap management 3. **ct-hscroll** - Horizontal scroll container with fade edges 4. **ct-vscroll** - Vertical scroll container with fade edges ### Form/Input Components (5) 1. **ct-aspect-ratio** - Maintains aspect ratio for content 2. **ct-collapsible** - Expandable/collapsible content section 3. **ct-progress** - Progress bar with determinate/indeterminate states 4. **ct-input-otp** - One-time password input with individual digits 5. **ct-radio-group** - Radio button group container ### Interactive Components (3) 1. **ct-toggle** - Toggle button with pressed state 2. **ct-toggle-group** - Toggle group for single/multiple selection 3. **ct-scroll-area** - Custom scrollable area with styled scrollbars ## Migration Pattern Applied For each component, the following changes were made: 1. **Imports** - Added Lit imports: `html`, `css`, `PropertyValues` - Added decorators: `@customElement`, `@property`, `@query`, `@state` - Added directives as needed: `classMap`, `styleMap`, `repeat` 2. **Class Declaration** - Added `@customElement` decorator - Changed styles to static with `css` template literal - Removed `observedAttributes` (handled by `@property`) 3. **Properties** - Converted getters/setters to `@property` with `accessor` keyword - Added appropriate types and options (reflect, attribute names) - Removed manual attribute management 4. **Lifecycle Methods** - `onConnect()` → `connectedCallback()` + `firstUpdated()` - `onDisconnect()` → `disconnectedCallback()` - `onAttributeChange()` → `updated(changedProperties)` - `onRender()` → `firstUpdated()` or `updated()` 5. **Templates** - `template()` → `render()` with `html` template literal - String concatenation → template expressions - Class manipulation → `classMap` directive - Style manipulation → `styleMap` directive - Array rendering → `repeat` directive where appropriate 6. **Event Handling** - Preserved all event handlers - Updated property references from `this._prop` to `this.prop` - Maintained custom event emission with `this.emit()` 7. **DOM Queries** - Manual queries → `@query` decorator for persistent references - `@queryAll` for NodeLists ## Benefits Achieved 1. **Type Safety** - Full TypeScript support with decorators 2. **Reactive Updates** - Automatic re-rendering on property changes 3. **Better Performance** - Lit's efficient rendering and diffing 4. **Cleaner Code** - Less boilerplate, more declarative 5. **Standard Compliance** - Following web component best practices