# Phase 2: Form Components Implementation Complete

## Overview
Successfully implemented reusable form component abstractions for the Type-Aware Node System project.

## Components Created

All components are located in `/frontend/apps/web/src/components/forms/`

### 1. FormField.tsx (61 lines)
**Purpose:** Base wrapper component providing consistent layout with label, error handling, and help text.

**Key Features:**
- Automatic ID and ARIA attribute management
- Error and help text display logic
- Required field indicator (red asterisk)
- Accessibility-first design with aria-describedby, aria-invalid, aria-required

**Props:**
```typescript
interface FormFieldProps {
  label: string;
  htmlFor: string;
  error?: string;
  helpText?: string;
  required?: boolean;
  children: React.ReactNode;
  className?: string;
}
```

### 2. FormInput.tsx (25 lines)
**Purpose:** Text input wrapper with error state styling.

**Key Features:**
- Compatible with react-hook-form forwardRef pattern
- Red border on error state
- Uses @tracertm/ui Input component
- Tailwind CSS styling with CVA

**Props:**
```typescript
interface FormInputProps extends React.InputHTMLAttributes<HTMLInputElement> {
  error?: boolean;
}
```

### 3. FormSelect.tsx (79 lines)
**Purpose:** Dropdown select using Radix UI Select component.

**Key Features:**
- Radix UI Select primitives (SelectTrigger, SelectContent, SelectItem)
- Type-safe options array
- Placeholder support
- Error state styling
- Proper handling of optional props for exactOptionalPropertyTypes

**Props:**
```typescript
interface FormSelectOption {
  label: string;
  value: string;
}

interface FormSelectProps {
  value: string | undefined;
  onValueChange: ((value: string) => void) | undefined;
  options: FormSelectOption[];
  placeholder?: string;
  error?: boolean;
  disabled?: boolean;
  // ... ARIA props
}
```

### 4. FormTextarea.tsx (26 lines)
**Purpose:** Multi-line textarea with error state styling.

**Key Features:**
- Compatible with react-hook-form
- Red border on error
- Uses @tracertm/ui Textarea component
- Configurable rows

**Props:**
```typescript
interface FormTextareaProps extends React.TextareaHTMLAttributes<HTMLTextAreaElement> {
  error?: boolean;
}
```

### 5. FormCheckbox.tsx (37 lines)
**Purpose:** Boolean checkbox with optional label.

**Key Features:**
- Uses existing Checkbox component from @/components/ui/checkbox
- Inline label support
- Automatic ID generation
- Error state styling
- Extends CheckboxProps for full compatibility

**Props:**
```typescript
interface FormCheckboxProps extends CheckboxProps {
  label?: string;
  error?: boolean;
}
```

### 6. FormArrayField.tsx (104 lines)
**Purpose:** Dynamic array manager with add/remove buttons using react-hook-form's useFieldArray.

**Key Features:**
- Add/remove buttons with Lucide icons (Plus, Trash2)
- Min/max item constraints
- Custom render function for field content
- Empty state message
- Item counter display
- ARIA labels for accessibility
- Border and background styling for array items

**Props:**
```typescript
interface FormArrayFieldProps<T extends FieldValues> {
  control: Control<T>;
  name: ArrayPath<T>;
  label: string;
  helpText?: string;
  renderField: (index: number) => React.ReactNode;
  defaultValue?: any;
  addButtonLabel?: string;
  removeButtonLabel?: string;
  minItems?: number;
  maxItems?: number;
  className?: string;
}
```

### 7. index.ts (19 lines)
**Purpose:** Centralized exports for all form components.

**Exports:**
- All component implementations
- All TypeScript types and interfaces
- CreateItemForm (existing form)

## Technical Implementation

### TypeScript Compliance
All components compile successfully with:
- `exactOptionalPropertyTypes: true`
- `verbatimModuleSyntax: true`
- Full type safety with react-hook-form integration

### Accessibility Features
All components include:
- ARIA attributes (aria-describedby, aria-invalid, aria-required)
- Semantic HTML elements
- Keyboard navigation support
- Focus management
- Error state indicators (visual + semantic)
- Screen reader compatible labels

### Styling Approach
- Tailwind CSS for all styling
- Class Variance Authority (CVA) where appropriate
- Consistent error states: `border-red-500 focus-visible:ring-red-500`
- Muted help text: `text-xs text-muted-foreground`
- Responsive layouts where needed

### react-hook-form Integration
All components use:
- `forwardRef` pattern for ref forwarding
- Compatible with `register()` function
- Controller support for complex components (FormSelect)
- useFieldArray integration (FormArrayField)
- Proper error handling from formState

## Dependencies

### External Packages
- `react` - Core React library
- `react-hook-form` - Form state management
- `@tracertm/ui` - UI component library (Input, Select, Textarea, Button, Label)
- `lucide-react` - Icons (Plus, Trash2)
- `class-variance-authority` - Styling variants

### Internal Dependencies
- `@/lib/utils` - cn() utility for classname merging
- `@/components/ui/checkbox` - Checkbox component

## File Structure
```
frontend/apps/web/src/components/forms/
├── FormField.tsx          # Base wrapper (61 lines)
├── FormInput.tsx          # Text input (25 lines)
├── FormSelect.tsx         # Dropdown (79 lines)
├── FormTextarea.tsx       # Textarea (26 lines)
├── FormCheckbox.tsx       # Checkbox (37 lines)
├── FormArrayField.tsx     # Array manager (104 lines)
├── index.ts               # Exports (19 lines)
├── README.md              # Documentation
└── [existing forms...]
```

## Code Statistics
- **New Components:** 6 form abstractions
- **Total Lines:** 351 lines of implementation code
- **Documentation:** Complete README with examples
- **Type Safety:** 100% TypeScript coverage
- **Export File:** Centralized index.ts

## Usage Example

```tsx
import { useForm, Controller } from "react-hook-form";
import { zodResolver } from "@hookform/resolvers/zod";
import { z } from "zod";
import {
  FormField,
  FormInput,
  FormSelect,
  FormTextarea,
  FormCheckbox,
  FormArrayField,
} from "@/components/forms";

const schema = z.object({
  title: z.string().min(1),
  category: z.string(),
  description: z.string().optional(),
  isPublic: z.boolean(),
  tags: z.array(z.object({ name: z.string() })),
});

function MyForm() {
  const { register, control, handleSubmit, formState: { errors } } = useForm({
    resolver: zodResolver(schema),
  });

  return (
    <form onSubmit={handleSubmit(onSubmit)}>
      <FormField label="Title" htmlFor="title" error={errors.title?.message} required>
        <FormInput {...register("title")} error={!!errors.title} />
      </FormField>

      <FormField label="Category" htmlFor="category" required>
        <Controller
          name="category"
          control={control}
          render={({ field }) => (
            <FormSelect
              value={field.value}
              onValueChange={field.onChange}
              options={[{ label: "Feature", value: "feature" }]}
            />
          )}
        />
      </FormField>

      <FormTextarea {...register("description")} rows={3} />

      <FormCheckbox {...register("isPublic")} label="Make public" />

      <FormArrayField
        control={control}
        name="tags"
        label="Tags"
        defaultValue={{ name: "" }}
        renderField={(index) => <FormInput {...register(`tags.${index}.name`)} />}
      />
    </form>
  );
}
```

## Testing Recommendations

### Unit Tests
- Test FormField ARIA attribute generation
- Test error state styling application
- Test FormArrayField add/remove functionality
- Test FormCheckbox label association
- Test FormSelect option rendering

### Integration Tests
- Test with react-hook-form validation
- Test keyboard navigation
- Test screen reader announcements
- Test error state transitions

### Accessibility Tests
- Run axe-core accessibility checks
- Test keyboard-only navigation
- Test with screen readers (VoiceOver, NVDA)
- Verify ARIA attributes with accessibility inspector

## Next Steps (Phase 3)

With these reusable form components ready, the next phase can:
1. Create type-specific node editors using these components
2. Implement dynamic form generation based on node schemas
3. Build form builders for custom node types
4. Add form validation patterns
5. Implement auto-save functionality

## Verification

TypeScript compilation: ✅ All form components compile without errors
Exports: ✅ All components properly exported from index.ts
Documentation: ✅ Complete README with usage examples
Accessibility: ✅ ARIA attributes and semantic HTML
react-hook-form: ✅ Full integration with forwardRef pattern
Styling: ✅ Consistent Tailwind CSS with error states

## Files Created

1. `/frontend/apps/web/src/components/forms/FormField.tsx`
2. `/frontend/apps/web/src/components/forms/FormInput.tsx`
3. `/frontend/apps/web/src/components/forms/FormSelect.tsx`
4. `/frontend/apps/web/src/components/forms/FormTextarea.tsx`
5. `/frontend/apps/web/src/components/forms/FormCheckbox.tsx`
6. `/frontend/apps/web/src/components/forms/FormArrayField.tsx`
7. `/frontend/apps/web/src/components/forms/index.ts`
8. `/frontend/apps/web/src/components/forms/README.md`

---

**Implementation Status:** ✅ COMPLETE
**Phase:** 2 of Type-Aware Node System
**Date:** 2026-01-30
