react中事件处理与柯里化的实现

const Button = () => {
    const handleClick = () => {
        console.log('click')
    }
    return <button onClick={handleClick}>click button</button>
}

const Button = () => {
    return (
        <button
            onClick={() => console.log('click')}
        >
            click button
        </button>)
}

const Link = () => {
    return <a
        href="https://www.baidu.com" rel="external nofollow"  rel="external nofollow" 
        onClick={(e) => e.preventDefault()}
    >
        link
    </a>
}

const Link = () => {
    const handleClick = (e: MouseEvent) => {
        e.preventDefault()
        console.log('click')
    }
    const handleMouseEnter:MouseEventHandler = (e) => {
        console.log('mouse enter')
    }
    return <a
        href="Https://www.baidu.com" rel="external nofollow"  rel="external nofollow" 
        onMouseEnter={handleMouseEnter}
        onClick={handleClick}
    >
        link
    </a>
}

//柯里化后的单参数函数
function sumCurrying(a) {
  return (b) => {
    return (c) => {
      return a + b + c;
    };
  };
}
//普通的多参数函数
function sumNORMal(a, b, c) {
  return a + b + c
}
console.log(sumCurrying(1)(2)(3));
console.log(sumNormal(1, 2, 3));

const List = () => {
    const list = [
        { id: 1, name: 'tom' },
        { id: 2, name: 'jerry' },
        { id: 3, name: 'jack' },
        { id: 4, name: 'lily' },
    ]
    const handleClick = (id: number) => {
        console.log(id)
    }
    return <ul>
        {list.map(item => <li
                onClick={() => handleClick(item.id)}
                key={item.id}
            >
                {item.name}
            </li>
        )}
    </ul>
}

//before
const handleClick = (id: number) => {
  console.log(id)
}
//after
const handleClick = (id: number) => (e:MouseEvent) => {
  console.log(id)
}

//原始函数
const log = (date, importance, message) => {
  alert(`[${date.getHours()}:${date.getMinutes()}] [${importance}] ${message}`);
}
//柯里化
const loGCurry = (date) => (importance) => (message) => { 
  alert(`[${date.getHours()}:${date.getMinutes()}] [${importance}] ${message}`);
}

// logNow 会是带有固定第一个参数的日志的函数
let logNow = logCurry(new Date());

// 使用它
logNow("INFO", "message"); // [HH:mm] INFO message

// debugNow 会是带有固定第一个参数与第二个参数的函数
let debugNow = logNow("DEBUG");

debugNow("message"); // [HH:mm] DEBUG message

const Form = () => {
   const [form, setForm] = React.useState({});
   const update = (name) => (event) => {
     setForm({
       ...form,
       [name]: event.target.value,
     });
   }
   const handleSubmit = (event) => {
     event.preventDefault();
     alert(`${JSON.stringify(form)}`);
   }
   return (
     <div>
       <h1>柯里化表单</h1>
       <FormItem label="用户名" name='username' update={update} />
       <FormItem label="昵称" name='nickname' update={update} />
       <FormItem label="邮箱" name='email' update={update} />
       <button onClick={handleSubmit}>提交</button>
     </div>
   )
 }

 const FormItem = ({ label, name, update }) => {
   return (
     <div style={{ 'display': 'flex' }}>
       <label>{label}</label>
       <input onChange={update(name)} type="text" placeholder={`请输入${label}`} />
     </div>
   );
 };