@foundrykit/hooks

A collection of custom React hooks for common UI patterns and functionality. Provides reusable logic for state management, user interactions, and component behavior.

Features

• Custom hooks - Reusable logic for common UI patterns
• TypeScript support - Full type safety with comprehensive definitions
• Performance optimized - Efficient implementations with proper cleanup
• Accessibility focused - Hooks that support accessibility best practices
• Framework agnostic - Works with any React setup

Installation

pnpm add @foundrykit/hooks

Available Hooks

State Management

• useLocalStorage - Persist state in localStorage
• useDebouncedValue - Debounce values for performance
• useMediaQuery - React to media query changes
• useClickOutside - Detect clicks outside elements

Form Hooks

• useForm - Form state management
• useField - Individual field management
• useValidation - Form validation logic

UI Hooks

• useDialog - Dialog/modal state management
• usePopover - Popover positioning and state
• useTooltip - Tooltip positioning and visibility

Utility Hooks

• usePrevious - Access previous value
• useInterval - Set up intervals with cleanup
• useTimeout - Set up timeouts with cleanup

Usage

State Management Hooks

useLocalStorage

Persist state in localStorage with automatic serialization:

import { useLocalStorage } from '@foundrykit/hooks';

function UserPreferences() {
  const [theme, setTheme] = useLocalStorage('theme', 'light');
  const [language, setLanguage] = useLocalStorage('language', 'en');

  return (
    <div>
      <select value={theme} onChange={e => setTheme(e.target.value)}>
        <option value='light'>Light</option>
        <option value='dark'>Dark</option>
      </select>

      <select value={language} onChange={e => setLanguage(e.target.value)}>
        <option value='en'>English</option>
        <option value='es'>Spanish</option>
      </select>
    </div>
  );
}

useDebouncedValue

Debounce values to improve performance:

import { useDebouncedValue } from '@foundrykit/hooks';

function SearchComponent() {
  const [query, setQuery] = useState('');
  const debouncedQuery = useDebouncedValue(query, 300);

  // This effect only runs when debouncedQuery changes
  useEffect(() => {
    if (debouncedQuery) {
      searchAPI(debouncedQuery);
    }
  }, [debouncedQuery]);

  return (
    <input
      value={query}
      onChange={e => setQuery(e.target.value)}
      placeholder='Search...'
    />
  );
}

useMediaQuery

React to media query changes:

import { useMediaQuery } from '@foundrykit/hooks';

function ResponsiveComponent() {
  const isMobile = useMediaQuery('(max-width: 768px)');
  const isTablet = useMediaQuery('(min-width: 769px) and (max-width: 1024px)');
  const isDesktop = useMediaQuery('(min-width: 1025px)');

  return (
    <div>
      {isMobile && <MobileLayout />}
      {isTablet && <TabletLayout />}
      {isDesktop && <DesktopLayout />}
    </div>
  );
}

UI Interaction Hooks

useClickOutside

Detect clicks outside an element:

import { useClickOutside } from '@foundrykit/hooks';

function Dropdown({ isOpen, onClose, children }) {
  const ref = useRef(null);

  useClickOutside(ref, () => {
    if (isOpen) {
      onClose();
    }
  });

  if (!isOpen) return null;

  return (
    <div ref={ref} className='dropdown'>
      {children}
    </div>
  );
}

useDialog

Manage dialog/modal state:

import { useDialog } from '@foundrykit/hooks';

function ModalExample() {
  const { isOpen, open, close, toggle } = useDialog();

  return (
    <div>
      <button onClick={open}>Open Modal</button>

      {isOpen && (
        <div className='modal-overlay' onClick={close}>
          <div className='modal-content' onClick={e => e.stopPropagation()}>
            <h2>Modal Content</h2>
            <button onClick={close}>Close</button>
          </div>
        </div>
      )}
    </div>
  );
}

Form Hooks

useForm

Complete form state management:

import { useForm } from '@foundrykit/hooks';

function ContactForm() {
  const {
    values,
    errors,
    touched,
    handleChange,
    handleBlur,
    handleSubmit,
    isSubmitting,
  } = useForm({
    initialValues: {
      name: '',
      email: '',
      message: '',
    },
    validate: values => {
      const errors = {};
      if (!values.name) errors.name = 'Name is required';
      if (!values.email) errors.email = 'Email is required';
      if (!values.message) errors.message = 'Message is required';
      return errors;
    },
    onSubmit: async values => {
      await submitForm(values);
    },
  });

  return (
    <form onSubmit={handleSubmit}>
      <input
        name='name'
        value={values.name}
        onChange={handleChange}
        onBlur={handleBlur}
        className={touched.name && errors.name ? 'error' : ''}
      />
      {touched.name && errors.name && <span>{errors.name}</span>}

      <input
        name='email'
        value={values.email}
        onChange={handleChange}
        onBlur={handleBlur}
        className={touched.email && errors.email ? 'error' : ''}
      />
      {touched.email && errors.email && <span>{errors.email}</span>}

      <textarea
        name='message'
        value={values.message}
        onChange={handleChange}
        onBlur={handleBlur}
        className={touched.message && errors.message ? 'error' : ''}
      />
      {touched.message && errors.message && <span>{errors.message}</span>}

      <button type='submit' disabled={isSubmitting}>
        {isSubmitting ? 'Sending...' : 'Send Message'}
      </button>
    </form>
  );
}

Utility Hooks

usePrevious

Access the previous value:

import { usePrevious } from '@foundrykit/hooks';

function Counter() {
  const [count, setCount] = useState(0);
  const previousCount = usePrevious(count);

  return (
    <div>
      <p>Current: {count}</p>
      <p>Previous: {previousCount}</p>
      <button onClick={() => setCount(count + 1)}>Increment</button>
    </div>
  );
}

useInterval

Set up intervals with automatic cleanup:

import { useInterval } from '@foundrykit/hooks';

function Timer() {
  const [seconds, setSeconds] = useState(0);
  const [isRunning, setIsRunning] = useState(false);

  useInterval(() => setSeconds(seconds + 1), isRunning ? 1000 : null);

  return (
    <div>
      <p>Seconds: {seconds}</p>
      <button onClick={() => setIsRunning(!isRunning)}>
        {isRunning ? 'Pause' : 'Start'}
      </button>
    </div>
  );
}

Advanced Usage

Custom Hook Composition

Combine multiple hooks for complex functionality:

import {
  useLocalStorage,
  useDebouncedValue,
  useMediaQuery,
} from '@foundrykit/hooks';

function useResponsiveSearch() {
  const [query, setQuery] = useLocalStorage('search-query', '');
  const debouncedQuery = useDebouncedValue(query, 300);
  const isMobile = useMediaQuery('(max-width: 768px)');

  const searchResults = useMemo(() => {
    if (!debouncedQuery) return [];
    return performSearch(debouncedQuery, { limit: isMobile ? 5 : 10 });
  }, [debouncedQuery, isMobile]);

  return {
    query,
    setQuery,
    debouncedQuery,
    searchResults,
    isMobile,
  };
}

Hook with Dependencies

import { useClickOutside } from '@foundrykit/hooks';

function useDropdown(initialState = false) {
  const [isOpen, setIsOpen] = useState(initialState);
  const ref = useRef(null);

  useClickOutside(ref, () => setIsOpen(false));

  const open = useCallback(() => setIsOpen(true), []);
  const close = useCallback(() => setIsOpen(false), []);
  const toggle = useCallback(() => setIsOpen(!isOpen), [isOpen]);

  return {
    isOpen,
    ref,
    open,
    close,
    toggle,
  };
}

Performance Optimization

import { useDebouncedValue } from '@foundrykit/hooks';

function OptimizedSearch() {
  const [query, setQuery] = useState('');
  const debouncedQuery = useDebouncedValue(query, 500);

  // Memoize expensive operation
  const searchResults = useMemo(() => {
    if (!debouncedQuery) return [];
    return expensiveSearch(debouncedQuery);
  }, [debouncedQuery]);

  return (
    <div>
      <input
        value={query}
        onChange={e => setQuery(e.target.value)}
        placeholder='Search...'
      />
      <SearchResults results={searchResults} />
    </div>
  );
}

TypeScript Support

All hooks include comprehensive TypeScript definitions:

import { useLocalStorage, useDebouncedValue } from '@foundrykit/hooks';

// Type-safe localStorage hook
const [user, setUser] = useLocalStorage<User>('user', null);

// Type-safe debounced value
const [searchTerm, setSearchTerm] = useState<string>('');
const debouncedSearchTerm = useDebouncedValue<string>(searchTerm, 300);

Best Practices

Hook Dependencies

// ✅ Good - Stable callback
const handleClick = useCallback(() => {
  console.log('clicked');
}, []);

// ❌ Avoid - Unstable callback
const handleClick = () => {
  console.log('clicked');
};

Cleanup

// ✅ Good - Proper cleanup
useEffect(() => {
  const timer = setTimeout(() => {
    // do something
  }, 1000);

  return () => clearTimeout(timer);
}, []);

// ❌ Avoid - Missing cleanup
useEffect(() => {
  setTimeout(() => {
    // do something
  }, 1000);
}, []);

Performance

// ✅ Good - Memoized expensive operations
const expensiveValue = useMemo(() => {
  return computeExpensiveValue(data);
}, [data]);

// ❌ Avoid - Recomputing on every render
const expensiveValue = computeExpensiveValue(data);

Contributing

When adding new hooks:

1. Follow React hooks best practices
2. Include comprehensive TypeScript definitions
3. Add JSDoc documentation
4. Write unit tests
5. Include usage examples
6. Update this README

License

MIT