tailwind-components（Tailwind CSS 组件）

Tailwind CSS - Component Patterns

While Tailwind is utility-first, you'll often want to extract common patterns into reusable components. This skill covers strategies for building maintainable component architectures with Tailwind.

Key Concepts

Component Extraction Strategies

There are several approaches to creating reusable components with Tailwind:

1. Template/Component Abstraction (Recommended)
2. CSS @apply Directive (Use sparingly)
3. JavaScript/TypeScript Component Classes
4. Tailwind Plugins

Template Component Abstraction

The most maintainable approach is to extract components at the template level:

// Button.tsx
interface ButtonProps {
  variant?: 'primary' | 'secondary' | 'outline'
  size?: 'sm' | 'md' | 'lg'
  children: React.ReactNode
  onClick?: () => void
}

export function Button({
  variant = 'primary',
  size = 'md',
  children,
  onClick
}: ButtonProps) {
  const baseClasses = 'font-semibold rounded transition-colors focus:ring-2 focus:ring-offset-2'

  const variantClasses = {
    primary: 'bg-blue-500 hover:bg-blue-600 text-white focus:ring-blue-300',
    secondary: 'bg-gray-500 hover:bg-gray-600 text-white focus:ring-gray-300',
    outline: 'border-2 border-blue-500 text-blue-500 hover:bg-blue-50 focus:ring-blue-300',
  }

  const sizeClasses = {
    sm: 'px-3 py-1.5 text-sm',
    md: 'px-4 py-2 text-base',
    lg: 'px-6 py-3 text-lg',
  }

  return (
    <button
      className={`${baseClasses} ${variantClasses[variant]} ${sizeClasses[size]}`}
      onClick={onClick}
    >
      {children}
    </button>
  )
}

Best Practices

1. Use Class Variance Authority (CVA)

For complex component variants, use cva for better type safety:

import { cva, type VariantProps } from 'class-variance-authority'

const button = cva(
  // Base classes
  'font-semibold rounded transition-colors focus:ring-2',
  {
    variants: {
      intent: {
        primary: 'bg-blue-500 hover:bg-blue-600 text-white',
        secondary: 'bg-gray-500 hover:bg-gray-600 text-white',
        danger: 'bg-red-500 hover:bg-red-600 text-white',
      },
      size: {
        small: 'text-sm px-3 py-1.5',
        medium: 'text-base px-4 py-2',
        large: 'text-lg px-6 py-3',
      },
      disabled: {
        true: 'opacity-50 cursor-not-allowed',
      },
    },
    compoundVariants: [
      {
        intent: 'primary',
        size: 'medium',
        className: 'uppercase',
      },
    ],
    defaultVariants: {
      intent: 'primary',
      size: 'medium',
    },
  }
)

interface ButtonProps extends VariantProps<typeof button> {
  children: React.ReactNode
}

export function Button({ intent, size, disabled, children }: ButtonProps) {
  return (
    <button className={button({ intent, size, disabled })}>
      {children}
    </button>
  )
}

2. Use clsx/cn for Conditional Classes

Combine multiple class strings efficiently:

import { clsx, type ClassValue } from 'clsx'
import { twMerge } from 'tailwind-merge'

export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs))
}

// Usage
<div className={cn(
  'base-classes',
  isActive && 'active-classes',
  isDisabled && 'disabled-classes',
  className // Allow props override
)} />

3. Create Compound Components

Build flexible component APIs:

// Card.tsx
interface CardProps {
  children: React.ReactNode
  className?: string
}

export function Card({ children, className }: CardProps) {
  return (
    <div className={cn(
      'bg-white rounded-lg shadow-md overflow-hidden',
      className
    )}>
      {children}
    </div>
  )
}

Card.Header = function CardHeader({ children, className }: CardProps) {
  return (
    <div className={cn('px-6 py-4 border-b border-gray-200', className)}>
      {children}
    </div>
  )
}

Card.Body = function CardBody({ children, className }: CardProps) {
  return (
    <div className={cn('px-6 py-4', className)}>
      {children}
    </div>
  )
}

Card.Footer = function CardFooter({ children, className }: CardProps) {
  return (
    <div className={cn('px-6 py-4 bg-gray-50 border-t border-gray-200', className)}>
      {children}
    </div>
  )
}

// Usage
<Card>
  <Card.Header>
    <h2 className="text-xl font-bold">Title</h2>
  </Card.Header>
  <Card.Body>
    <p>Content goes here</p>
  </Card.Body>
  <Card.Footer>
    <button>Action</button>
  </Card.Footer>
</Card>

4. Use @apply Sparingly

Only use @apply for truly reusable base styles:

/* globals.css */
@layer components {
  .btn {
    @apply px-4 py-2 rounded font-semibold transition-colors;
  }

  .btn-primary {
    @apply bg-blue-500 hover:bg-blue-600 text-white;
  }

  .btn-secondary {
    @apply bg-gray-500 hover:bg-gray-600 text-white;
  }
}

Note: Prefer component abstraction over @apply to maintain Tailwind's utility-first benefits.

5. Design System Integration

Create a centralized design system:

// design-system/index.ts
export const colors = {
  primary: 'blue-500',
  secondary: 'gray-500',
  success: 'green-500',
  danger: 'red-500',
  warning: 'yellow-500',
}

export const spacing = {
  xs: '1',
  sm: '2',
  md: '4',
  lg: '6',
  xl: '8',
}

export const typography = {
  heading: 'font-bold tracking-tight',
  body: 'font-normal leading-relaxed',
  caption: 'text-sm text-gray-600',
}

// Usage in components
import { colors, spacing } from '@/design-system'

<button className={`bg-${colors.primary} p-${spacing.md}`}>
  Click me
</button>

Examples

Form Input Component

import { forwardRef } from 'react'
import { cn } from '@/lib/utils'

interface InputProps extends React.InputHTMLAttributes<HTMLInputElement> {
  label?: string
  error?: string
  helperText?: string
}

export const Input = forwardRef<HTMLInputElement, InputProps>(
  ({ label, error, helperText, className, ...props }, ref) => {
    return (
      <div className="w-full">
        {label && (
          <label className="block text-sm font-medium text-gray-700 mb-1">
            {label}
          </label>
        )}
        <input
          ref={ref}
          className={cn(
            'w-full px-3 py-2 border rounded-md',
            'focus:outline-none focus:ring-2 focus:ring-offset-0',
            'transition-colors',
            error
              ? 'border-red-500 focus:ring-red-300'
              : 'border-gray-300 focus:ring-blue-300',
            props.disabled && 'bg-gray-100 cursor-not-allowed',
            className
          )}
          {...props}
        />
        {error && (
          <p className="mt-1 text-sm text-red-600">{error}</p>
        )}
        {helperText && !error && (
          <p className="mt-1 text-sm text-gray-500">{helperText}</p>
        )}
      </div>
    )
  }
)

Input.displayName = 'Input'

Modal Component

import { useEffect } from 'react'
import { createPortal } from 'react-dom'
import { cn } from '@/lib/utils'

interface ModalProps {
  isOpen: boolean
  onClose: () => void
  children: React.ReactNode
  title?: string
  size?: 'sm' | 'md' | 'lg' | 'xl'
}

export function Modal({
  isOpen,
  onClose,
  children,
  title,
  size = 'md'
}: ModalProps) {
  useEffect(() => {
    if (isOpen) {
      document.body.style.overflow = 'hidden'
    } else {
      document.body.style.overflow = 'unset'
    }
    return () => {
      document.body.style.overflow = 'unset'
    }
  }, [isOpen])

  if (!isOpen) return null

  const sizeClasses = {
    sm: 'max-w-md',
    md: 'max-w-lg',
    lg: 'max-w-2xl',
    xl: 'max-w-4xl',
  }

  return createPortal(
    <div className="fixed inset-0 z-50 overflow-y-auto">
      {/* Backdrop */}
      <div
        className="fixed inset-0 bg-black bg-opacity-50 transition-opacity"
        onClick={onClose}
      />

      {/* Modal */}
      <div className="flex min-h-screen items-center justify-center p-4">
        <div
          className={cn(
            'relative bg-white rounded-lg shadow-xl',
            'w-full transform transition-all',
            sizeClasses[size]
          )}
        >
          {/* Header */}
          {title && (
            <div className="px-6 py-4 border-b border-gray-200">
              <h2 className="text-xl font-semibold">{title}</h2>
              <button
                onClick={onClose}
                className="absolute top-4 right-4 text-gray-400 hover:text-gray-600"
              >
                <svg className="w-6 h-6" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
                </svg>
              </button>
            </div>
          )}

          {/* Content */}
          <div className="px-6 py-4">
            {children}
          </div>
        </div>
      </div>
    </div>,
    document.body
  )
}

Dropdown Menu Component

import { useState, useRef, useEffect } from 'react'
import { cn } from '@/lib/utils'

interface DropdownProps {
  trigger: React.ReactNode
  children: React.ReactNode
  align?: 'left' | 'right'
}

export function Dropdown({ trigger, children, align = 'left' }: DropdownProps) {
  const [isOpen, setIsOpen] = useState(false)
  const dropdownRef = useRef<HTMLDivElement>(null)

  useEffect(() => {
    function handleClickOutside(event: MouseEvent) {
      if (dropdownRef.current && !dropdownRef.current.contains(event.target as Node)) {
        setIsOpen(false)
      }
    }

    document.addEventListener('mousedown', handleClickOutside)
    return () => document.removeEventListener('mousedown', handleClickOutside)
  }, [])

  return (
    <div className="relative inline-block" ref={dropdownRef}>
      <div onClick={() => setIsOpen(!isOpen)}>
        {trigger}
      </div>

      {isOpen && (
        <div className={cn(
          'absolute z-50 mt-2 w-56',
          'bg-white rounded-md shadow-lg',
          'border border-gray-200',
          'py-1',
          align === 'right' ? 'right-0' : 'left-0'
        )}>
          {children}
        </div>
      )}
    </div>
  )
}

Dropdown.Item = function DropdownItem({
  children,
  onClick
}: {
  children: React.ReactNode
  onClick?: () => void
}) {
  return (
    <button
      className={cn(
        'w-full text-left px-4 py-2',
        'hover:bg-gray-100',
        'transition-colors'
      )}
      onClick={onClick}
    >
      {children}
    </button>
  )
}

Common Patterns

Loading States

export function LoadingButton({
  isLoading,
  children,
  ...props
}: ButtonProps & { isLoading?: boolean }) {
  return (
    <button
      className={cn(
        'relative',
        isLoading && 'cursor-not-allowed opacity-70'
      )}
      disabled={isLoading}
      {...props}
    >
      {isLoading && (
        <span className="absolute inset-0 flex items-center justify-center">
          <svg className="animate-spin h-5 w-5" viewBox="0 0 24 24">
            <circle
              className="opacity-25"
              cx="12"
              cy="12"
              r="10"
              stroke="currentColor"
              strokeWidth="4"
              fill="none"
            />
            <path
              className="opacity-75"
              fill="currentColor"
              d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"
            />
          </svg>
        </span>
      )}
      <span className={cn(isLoading && 'invisible')}>
        {children}
      </span>
    </button>
  )
}

Badge Component

const badge = cva(
  'inline-flex items-center rounded-full font-medium',
  {
    variants: {
      variant: {
        default: 'bg-gray-100 text-gray-800',
        primary: 'bg-blue-100 text-blue-800',
        success: 'bg-green-100 text-green-800',
        warning: 'bg-yellow-100 text-yellow-800',
        danger: 'bg-red-100 text-red-800',
      },
      size: {
        sm: 'px-2 py-0.5 text-xs',
        md: 'px-2.5 py-1 text-sm',
        lg: 'px-3 py-1.5 text-base',
      },
    },
    defaultVariants: {
      variant: 'default',
      size: 'md',
    },
  }
)

export function Badge({ variant, size, children }: VariantProps<typeof badge> & { children: React.ReactNode }) {
  return (
    <span className={badge({ variant, size })}>
      {children}
    </span>
  )
}

Anti-Patterns

❌ Don't Overuse @apply

/* Bad: Recreating Bootstrap */
.btn {
  @apply px-4 py-2 rounded font-semibold transition-colors focus:ring-2;
}
.btn-primary {
  @apply bg-blue-500 hover:bg-blue-600 text-white focus:ring-blue-300;
}
.btn-secondary {
  @apply bg-gray-500 hover:bg-gray-600 text-white focus:ring-gray-300;
}
.btn-sm { @apply px-3 py-1 text-sm; }
.btn-lg { @apply px-6 py-3 text-lg; }

/* Good: Component abstraction instead */

❌ Don't Create Overly Generic Components

// Bad: Too flexible, loses Tailwind benefits
<Box padding="4" margin="2" bg="blue" />

// Good: Semantic components
<Card className="p-4 m-2 bg-blue-500" />

❌ Don't Ignore Prop Overrides

// Bad: Can't override styles
export function Button({ children }: { children: React.ReactNode }) {
  return <button className="bg-blue-500 px-4 py-2">{children}</button>
}

// Good: Accept className prop
export function Button({ children, className }: { children: React.ReactNode; className?: string }) {
  return (
    <button className={cn('bg-blue-500 px-4 py-2', className)}>
      {children}
    </button>
  )
}

Related Skills

• tailwind-utility-classes: Using Tailwind's utility classes effectively
• tailwind-configuration: Customizing Tailwind config and theme
• tailwind-responsive-design: Building responsive component patterns