hooks

Instruction file imported from joshcristopher/Lovable.Boilerplate (.cursor/rules/hooks.mdc). Copyright stays with the author.

Custom Hooks Rules

Hook Organization Patterns

Data Fetching Hooks

// hooks/useUsers.ts
export const useUsers = () => {
  return useQuery({
    queryKey: ['users'],
    queryFn: () => userService.getAllUsers(),
    staleTime: 5 * 60 * 1000, // 5 minutes
  })
}

export const useUser = (id: string) => {
  return useQuery({
    queryKey: ['users', id],
    queryFn: () => userService.getUser(id),
    enabled: !!id,
  })
}

Form Hooks

// hooks/useUserForm.ts
export const useUserForm = (initialData?: Partial<User>) => {
  const form = useForm<UserFormData>({
    resolver: zodResolver(userSchema),
    defaultValues: initialData || {},
  })

  const { mutate: saveUser, isPending } = useMutation({
    mutationFn: userService.updateUser,
    onSuccess: () => toast.success('User saved'),
    onError: (error) => toast.error(error.message),
  })

  return { form, saveUser, isPending }
}

UI State Hooks

// hooks/useDisclosure.ts
export const useDisclosure = (initialState = false) => {
  const [isOpen, setIsOpen] = useState(initialState)
  
  const open = useCallback(() => setIsOpen(true), [])
  const close = useCallback(() => setIsOpen(false), [])
  const toggle = useCallback(() => setIsOpen(prev => !prev), [])
  
  return { isOpen, open, close, toggle }
}

Local Storage Hook

// hooks/useLocalStorage.ts
export const useLocalStorage = <T>(key: string, initialValue: T) => {
  const [storedValue, setStoredValue] = useState<T>(() => {
    try {
      const item = window.localStorage.getItem(key)
      return item ? JSON.parse(item) : initialValue
    } catch (error) {
      return initialValue
    }
  })

  const setValue = useCallback((value: T | ((val: T) => T)) => {
    try {
      const valueToStore = value instanceof Function ? value(storedValue) : value
      setStoredValue(valueToStore)
      window.localStorage.setItem(key, JSON.stringify(valueToStore))
    } catch (error) {
      console.error(error)
    }
  }, [key, storedValue])

  return [storedValue, setValue] as const
}

Hook Naming Conventions

• Data: useUsers, useUser, useProducts
• Forms: useUserForm, useProductForm
• UI State: useDisclosure, useToggle, useLocalStorage
• Business Logic: useAuth, useCart, useNotifications

Hook Extraction Rules

Extract Logic When:

• Same logic used in 2+ components
• Component exceeds 100 lines due to logic
• Complex state management patterns
• API interaction patterns

Don't Extract When:

• Logic is component-specific
• Only used once
• Simple useState patterns