Headless UI का परिचय

# Install for React
npm install @headlessui/react

# Install for Vue
npm install @headlessui/vue

# Available components:
# Menu, Dialog, Listbox, Combobox,
# Switch, Disclosure, Popover, RadioGroup,
# Tab (Tabs, TabGroup, TabList, TabPanel)

import { Menu, Dialog, Listbox } from '@headlessui/react';

import { Switch } from '@headlessui/react';
import { useState } from 'react';

function ToggleSwitch() {
  const [enabled, setEnabled] = useState(false);

  return (
    <Switch
      checked={enabled}
      onChange={setEnabled}
      className={cn(
        'relative inline-flex h-6 w-11 items-center rounded-full transition-colors',
        enabled ? 'bg-blue-600' : 'bg-gray-200'
      )}
    >
      <span className={cn(
        'inline-block h-4 w-4 transform rounded-full bg-white transition-transform',
        enabled ? 'translate-x-6' : 'translate-x-1'
      )} />
    </Switch>
  );
}

import { Menu } from '@headlessui/react';

function UserMenu() {
  return (
    <Menu as='div' className='relative'>
      <Menu.Button className='flex items-center gap-2 rounded-lg px-3 py-2 hover:bg-gray-100'>
        <img src='/avatar.png' className='h-8 w-8 rounded-full' alt='User' />
        <span className='text-sm font-medium'>John Doe</span>
      </Menu.Button>

      <Menu.Items className='absolute right-0 mt-2 w-48 rounded-xl bg-white shadow-lg ring-1 ring-black/5 focus:outline-none'>
        <div className='p-1'>
          <Menu.Item>
            {({ active }) => (
              <button className={cn('w-full text-left px-3 py-2 text-sm rounded-lg', active && 'bg-gray-100')}>
                Profile
              </button>
            )}
          </Menu.Item>
        </div>
      </Menu.Items>
    </Menu>
  );
}

// Render props expose internal state
<Menu.Button>
  {({ open }) => (
    <span className={cn(
      'flex items-center gap-2 px-4 py-2 rounded-lg',
      open ? 'bg-blue-50 text-blue-600' : 'text-gray-700 hover:bg-gray-100'
    )}>
      Options
      <ChevronDownIcon className={cn(
        'h-4 w-4 transition-transform',
        open && 'rotate-180'
      )} />
    </span>
  )}
</Menu.Button>

// Menu.Item with active state
<Menu.Item>
  {({ active, disabled }) => (
    <button className={cn(
      'w-full px-3 py-2 text-sm text-left rounded',
      active && 'bg-blue-600 text-white',
      disabled && 'opacity-50 cursor-not-allowed'
    )}>
      Edit
    </button>
  )}
</Menu.Item>

import { Dialog } from '@headlessui/react';

function ConfirmModal({ isOpen, onClose }) {
  return (
    <Dialog open={isOpen} onClose={onClose} className='relative z-50'>
      {/* Backdrop */}
      <div className='fixed inset-0 bg-black/40' aria-hidden='true' />

      {/* Center the panel */}
      <div className='fixed inset-0 flex items-center justify-center p-4'>
        <Dialog.Panel className='bg-white rounded-2xl shadow-xl max-w-md w-full p-6'>
          <Dialog.Title className='text-lg font-semibold text-gray-900'>
            Confirm Action
          </Dialog.Title>
          <Dialog.Description className='mt-2 text-sm text-gray-600'>
            Are you sure you want to continue?
          </Dialog.Description>
          <div className='mt-6 flex gap-3 justify-end'>
            <button onClick={onClose} className='px-4 py-2 text-sm rounded-lg border'>Cancel</button>
            <button className='px-4 py-2 text-sm rounded-lg bg-blue-600 text-white'>Confirm</button>
          </div>
        </Dialog.Panel>
      </div>
    </Dialog>
  );
}

import { Disclosure } from '@headlessui/react';

function FAQItem({ question, answer }) {
  return (
    <Disclosure as='div' className='border-b border-gray-200 py-4'>
      {({ open }) => (
        <>
          <Disclosure.Button className='flex w-full justify-between items-center text-left'>
            <span className='font-medium text-gray-900'>{question}</span>
            <ChevronDownIcon className={cn(
              'h-5 w-5 text-gray-500 transition-transform',
              open && 'rotate-180'
            )} />
          </Disclosure.Button>

          <Disclosure.Panel className='mt-3 text-sm text-gray-600 leading-relaxed'>
            {answer}
          </Disclosure.Panel>
        </>
      )}
    </Disclosure>
  );
}

import { Listbox } from '@headlessui/react';

const people = [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }];

function PersonSelect({ value, onChange }) {
  return (
    <Listbox value={value} onChange={onChange}>
      <div className='relative'>
        <Listbox.Button className='w-full rounded-lg border border-gray-300 bg-white px-4 py-2 text-left text-sm'>
          {value.name}
        </Listbox.Button>

        <Listbox.Options className='absolute z-10 mt-1 w-full rounded-xl bg-white shadow-lg ring-1 ring-black/5'>
          {people.map(person => (
            <Listbox.Option key={person.id} value={person}>
              {({ active, selected }) => (
                <div className={cn('px-4 py-2 text-sm cursor-pointer', active && 'bg-blue-50')}>
                  {selected && <CheckIcon className='inline h-4 w-4 mr-2 text-blue-600' />}
                  {person.name}
                </div>
              )}
            </Listbox.Option>
          ))}
        </Listbox.Options>
      </div>
    </Listbox>
  );
}

import { Tab } from '@headlessui/react';

function TabbedContent() {
  return (
    <Tab.Group>
      <Tab.List className='flex gap-1 rounded-xl bg-gray-100 p-1'>
        {['Overview', 'Analytics', 'Settings'].map(tab => (
          <Tab
            key={tab}
            className={({ selected }) => cn(
              'flex-1 rounded-lg py-2 text-sm font-medium transition-colors',
              selected
                ? 'bg-white text-blue-700 shadow'
                : 'text-gray-600 hover:text-gray-900'
            )}
          >
            {tab}
          </Tab>
        ))}
      </Tab.List>

      <Tab.Panels className='mt-4'>
        <Tab.Panel className='p-4 rounded-xl bg-white'><p>Overview content</p></Tab.Panel>
        <Tab.Panel className='p-4 rounded-xl bg-white'><p>Analytics content</p></Tab.Panel>
        <Tab.Panel className='p-4 rounded-xl bg-white'><p>Settings content</p></Tab.Panel>
      </Tab.Panels>
    </Tab.Group>
  );
}

<!-- What Headless UI generates automatically -->
<!-- For Menu.Button -->
<button
  id='headlessui-menu-button-1'
  type='button'
  aria-haspopup='true'
  aria-expanded='true'
  aria-controls='headlessui-menu-items-2'
>
  Options
</button>

<!-- For Menu.Items -->
<ul
  id='headlessui-menu-items-2'
  role='menu'
  aria-labelledby='headlessui-menu-button-1'
  tabindex='-1'
>
  <li role='menuitem'>...</li>
</ul>

<!-- All generated automatically — no manual ARIA needed -->

import { Tab, Switch, Dialog } from '@headlessui/react';

// Settings page combining multiple Headless UI components
function SettingsPage() {
  return (
    <Tab.Group>
      <Tab.List class='flex gap-1 border-b border-gray-200 mb-6'>
        <Tab class={({ selected }) =>
          cn('px-4 py-2 text-sm font-medium border-b-2 -mb-px',
            selected ? 'border-blue-500 text-blue-600' : 'border-transparent text-gray-500')
        }>Profile</Tab>
        <Tab class={({ selected }) =>
          cn('px-4 py-2 text-sm font-medium border-b-2 -mb-px',
            selected ? 'border-blue-500 text-blue-600' : 'border-transparent text-gray-500')
        }>Notifications</Tab>
      </Tab.List>
      <Tab.Panels>
        <Tab.Panel>{/* Profile settings with Switch toggles */}</Tab.Panel>
        <Tab.Panel>{/* Notification settings */}</Tab.Panel>
      </Tab.Panels>
    </Tab.Group>
  );
}