# Form Builder Technical Appendix
This document provides technical implementation details for developers working with the Form Builder system.
> For user documentation and usage guidelines, please refer to [Form Builder Documentation](FORM_BUILDER_DOCUMENTATION.md)
## Architecture Overview
### Technology Stack
- **Frontend Framework**: Nuxt 3 / Vue 3
- **State Management**: Pinia
- **Form Library**: FormKit
- **UI Framework**: Tailwind CSS
- **Icons**: Material Design Icons
- **Drag & Drop**: vuedraggable
### Key Dependencies
```json
{
"@formkit/nuxt": "^1.0.0",
"@pinia/nuxt": "^0.4.11",
"vuedraggable": "^4.1.0",
"@vueuse/core": "^10.1.2",
"tailwindcss": "^3.3.2"
}
```
## Project Structure
```
pages/
├── form-builder/
│ ├── index.vue # Main builder interface
│ └── manage.vue # Form management
components/
├── FormBuilderComponents.vue # Component library
├── FormBuilderCanvas.vue # Form canvas
├── FormBuilderConfiguration.vue # Component config
└── ComponentPreview.vue # Preview renderer
stores/
└── formBuilder.js # State management
composables/
└── useToast.js # Toast notifications
types/
└── form-builder.d.ts # TypeScript definitions
```
## Component Architecture
### Core Components
1. **FormBuilderComponents.vue**
```vue
```
2. **FormBuilderCanvas.vue**
```vue
```
## State Management
### Pinia Store Structure
```typescript
interface FormState {
formComponents: FormComponent[];
selectedComponentId: string | null;
formName: string;
formDescription: string;
isDraggingOver: boolean;
savedForms: SavedForm[];
}
export const useFormBuilderStore = defineStore('formBuilder', {
state: (): FormState => ({
formComponents: [],
selectedComponentId: null,
formName: 'New Form',
formDescription: '',
isDraggingOver: false,
savedForms: []
}),
getters: {
selectedComponent: (state) => // Implementation
formConfig: (state) => // Implementation
},
actions: {
addComponent(component: FormComponent) // Implementation
updateComponent(id: string, updates: Partial) // Implementation
deleteComponent(id: string) // Implementation
moveComponent(oldIndex: number, newIndex: number) // Implementation
}
});
```
## Form Component Types
### Type Definitions
```typescript
interface BaseComponent {
id: string;
type: string;
name: string;
category: ComponentCategory;
icon: string;
props: BaseComponentProps;
}
interface BaseComponentProps {
name: string;
label: string;
help?: string;
validation?: string;
width?: number;
}
interface InputComponent extends BaseComponent {
props: InputComponentProps;
}
interface SelectComponent extends BaseComponent {
props: SelectComponentProps;
}
// Additional type definitions...
```
## Validation System
### Implementation
```typescript
const validationRules = {
required: 'Value is required',
email: 'Invalid email format',
min: (min: number) => `Minimum value is ${min}`,
max: (max: number) => `Maximum value is ${max}`,
between: (min: number, max: number) =>
`Value must be between ${min} and ${max}`,
pattern: (pattern: string) =>
`Value must match pattern: ${pattern}`
};
const validateField = (value: any, rules: string) => {
// Validation implementation
};
```
## Grid System
### Implementation
```typescript
const gridSystem = {
columns: 12,
breakpoints: {
sm: 640,
md: 768,
lg: 1024,
xl: 1280
},
calculateSpan: (width: number) =>
Math.min(Math.max(1, Math.round(width * 12)), 12)
};
```
## Event Handling
### Component Events
```typescript
const componentEvents = {
onAdd: (event: DragEvent) => void;
onUpdate: (event: UpdateEvent) => void;
onSelect: (id: string) => void;
onDelete: (id: string) => void;
onDuplicate: (id: string) => void;
onValidate: (component: FormComponent) => ValidationResult;
};
```
## Performance Optimization
### Implementation Details
1. **Component Lazy Loading**
```typescript
const ComponentPreview = defineAsyncComponent(() =>
import('./ComponentPreview.vue')
);
```
2. **Virtual Scrolling**
```typescript
const virtualScroller = {
itemSize: 50,
minItemsPerPage: 10,
maxBufferPx: 200
};
```
3. **Debounced Updates**
```typescript
const debouncedSave = useDebounceFn(() => {
saveFormToStorage();
}, 500);
```
## Development Guidelines
### Component Development
1. Follow Vue 3 Composition API patterns
2. Implement proper TypeScript types
3. Use props validation
4. Emit typed events
5. Document component API
### State Management
1. Use Pinia for global state
2. Implement proper actions and getters
3. Use computed properties for derived state
4. Handle side effects in actions
### Styling
1. Use Tailwind utility classes
2. Follow BEM for custom CSS
3. Implement responsive design
4. Use CSS variables for theming
### Testing
1. Write unit tests for components
2. Test store actions and mutations
3. Implement E2E tests for critical paths
4. Test responsive behavior
## Error Handling
### Implementation
```typescript
const errorHandler = {
handleValidationError: (error: ValidationError) => {
// Handle validation errors
},
handleDragError: (error: DragError) => {
// Handle drag and drop errors
},
handleStateError: (error: StateError) => {
// Handle state management errors
}
};
```
## Security Considerations
1. **Input Sanitization**
```typescript
const sanitizeInput = (input: string): string => {
// Sanitization implementation
};
```
2. **Form Validation**
```typescript
const validateForm = async (form: FormData): Promise => {
// Validation implementation
};
```
## Build and Deployment
### Build Configuration
```javascript
// nuxt.config.ts
export default defineNuxtConfig({
// Configuration details
});
```
### Development Setup
```bash
# Installation
npm install
# Development
npm run dev
# Build
npm run build
# Preview
npm run preview
```
---
For user documentation and usage guidelines, please refer to [Form Builder Documentation](FORM_BUILDER_DOCUMENTATION.md).
Last updated: April 9, 2025