XML Form Renderer Documentation

Project Overview

The XML Form Renderer is a React Native application that parses XML-based form definitions and renders them as interactive forms. The application supports various form elements including text fields, date/time inputs, radio buttons, and signature drawing fields.

Project Structure

XMLFormRenderer/
├── components/
│   ├── FormRenderer.js
│   ├── TextField.js
│   ├── DateTimeField.js
│   ├── RadioButtons.js
│   └── DrawingField.js
├── utils/
│   ├── xmlParser.js
│   └── validation.js
└── App.js

Component Documentation

App.js

The root component that sets up the application environment.

// Main application wrapper
export default function App() {
  return (
    <SafeAreaProvider>
      <GestureHandlerRootView style={{ flex: 1 }}>
        <HomeScreen />
      </GestureHandlerRootView>
    </SafeAreaProvider>
  );
}

Purpose: Provides necessary providers and root layout for the application.

FormRenderer.js

The main component responsible for rendering the form based on parsed XML data.

Key Functions:

const FormRenderer = ({ xml }) => {
  // State management for form data
  const [formFields, setFormFields] = useState([]);
  const [formData, setFormData] = useState({});
}

Responsibilities:

• Parses XML input using xmlParser
• Manages form state
• Renders appropriate form components
• Handles form data changes
• Provides form validation

TextField.js

Handles character-by-character text input with auto-progression.

Key Features:

const TextField = ({ label, value, onChangeText, length = 20 }) => {
  const inputRefs = useRef(Array(length).fill(null));
  
  const handleCharChange = (text, index) => {
    // Auto-progression logic
  };
}

Functionality:

• Individual character inputs
• Automatic cursor progression
• Backspace handling
• Character validation
• Visual formatting

DateTimeField.js

Provides date and time input functionality.

Implementation:

const DateTimeField = ({ label, value, onChange }) => {
  const formattedDate = value ? new Date(value) : new Date();
  
  return (
    <DateTimePicker
      value={formattedDate}
      mode="date"
      // ...
    />
  );
}

Features:

• Native date picker integration
• Date formatting
• Date validation
• Default value handling

RadioButtons.js

Implements radio button group functionality.

Core Logic:

const RadioButtons = ({ label, options, selectedValue, onSelect }) => {
  return (
    <View style={styles.container}>
      {options.map((option, index) => (
        <TouchableOpacity
          onPress={() => onSelect(option.value)}
          // ...
        />
      ))}
    </View>
  );
}

Features:

• Multiple option support
• Custom styling
• Selection state management
• Accessibility support

DrawingField.js

Provides signature or drawing functionality.

Implementation:

const DrawingField = ({ label, onDrawingChange }) => {
  const pathRef = useRef('');
  const pointsRef = useRef([]);

  const pan = Gesture.Pan()
    .onBegin((e) => {
      // Drawing logic
    });
}

Features:

• Gesture handling
• SVG path drawing
• Real-time updates
• Drawing state management

Utility Functions

xmlParser.js

Handles XML parsing and form field extraction.

Key Functions:

export const parseXML = (xml) => {
  return new Promise((resolve, reject) => {
    // XML parsing logic
  });
}

Responsibilities:

• XML string cleanup
• Structure parsing
• Field extraction
• Label finding
• Radio button label handling

validation.js

Provides form validation functionality.

Implementation:

export const validateField = (field, value) => {
  const errors = [];
  // Validation logic per field type
  return errors;
};

Validation Types:

• Required field validation
• Length validation
• Date format validation
• Option validation

XML Structure

The application expects XML in the following format:

<div>
  <div class="formSide">
    <svg>
      <!-- Form elements defined here -->
      <g fdtType="iso">
        <!-- Text input definition -->
      </g>
      <g fdtType="radioList">
        <!-- Radio button definition -->
      </g>
      <!-- Other form elements -->
    </svg>
  </div>
</div>

Usage Example

// In your screen component
import FormRenderer from './components/FormRenderer';

const HomeScreen = () => {
  return (
    <FormRenderer xml={yourXMLString} />
  );
};

Dependencies

• @react-native-community/datetimepicker: ^7.6.1
• react-native-gesture-handler: ~2.14.0
• react-native-svg: ^14.1.0

Error Handling

The application includes comprehensive error handling:

• XML parsing errors
• Validation errors
• Input errors
• State management errors

Performance Considerations

• Uses refs for optimized input handling
• Implements proper React state management
• Optimizes re-renders
• Handles memory management for drawing operations

Accessibility

The application implements accessibility features:

• Screen reader support
• Keyboard navigation
• Focus management
• Clear labeling

Working Application SneekPeek