我是ReactJS和JSX的新手,我对下面的代码有一个小问题。

我试图在每个li上添加多个类到className属性:

<li key={index} className={activeClass, data.class, "main-class"}></li>

我的React组件是:

var AccountMainMenu = React.createClass({
  getInitialState: function() {
    return { focused: 0 };
  },

  clicked: function(index) {
    this.setState({ focused: index });
  },

  render: function() {
    var self = this;
    var accountMenuData = [
      {
        name: "My Account",
        icon: "icon-account"
      },
      {
        name: "Messages",
        icon: "icon-message"
      },
      {
        name: "Settings",
        icon: "icon-settings"
      }
    /*{
        name:"Help &amp; Support &nbsp; <span class='font-awesome icon-support'></span>(888) 664.6261",
        listClass:"no-mobile last help-support last"
      }*/
    ];

    return (
      <div className="acc-header-wrapper clearfix">
        <ul className="acc-btns-container">
          {accountMenuData.map(function(data, index) {
            var activeClass = "";

            if (self.state.focused == index) {
              activeClass = "active";
            }

            return (
              <li
                key={index}
                className={activeClass}
                onClick={self.clicked.bind(self, index)}
              >
                <a href="#" className={data.icon}>
                  {data.name}
                </a>
              </li>
            );
          })}
        </ul>
      </div>
    );
  }
});

ReactDOM.render(<AccountMainMenu />, document.getElementById("app-container"));

当前回答

香草JS

不需要外部库-只需使用ES6模板字符串:

<i className={`${styles['foo-bar-baz']} fa fa-user fa-2x`}/>

其他回答

使用字符串连接来连接CSS类是个坏主意。在很多情况下,这是非常令人困惑和压倒性的。最好添加一些简单的帮助器,将所有这些连接到一个字符串中。这里有一个例子:

import isString from 'lodash/isString';
import isObject from 'lodash/isObject';
/**
 * Helper function for conditionally creating css class strings.
 *
 * Example usage:
 *   classNames('foo', ['bar', ''], { baz: false, bob: true });
 *   => 'foo bar bob'
 *
 * @module helpers/classNames
 * @param {...(String|String[]|Object)} args
 * @returns {String}
 */
export default function classNames(...args) {
  const classes = [];
  for (const arg of args) {
    if (arg !== null && typeof arg !== 'undefined') {
        if (isString(arg)) {
          classes.push(arg);
        } else if (Array.isArray(arg)) {
          classes.push(classNames(...arg));
        } else if (isObject(arg)) {
          classes.push(classNames(...Object.keys(arg).filter(k => arg[k])));
        }
    }
  }
  return classes.join(' ');
}

(来自https://tomsoir.medium.com/react-css-classnames-concatenation-pattern-fd0fa1f31143)

香草JS

不需要外部库-只需使用ES6模板字符串:

<i className={`${styles['foo-bar-baz']} fa fa-user fa-2x`}/>

只需将join(' ')函数与空格链接到数组,例如:

<p className={['alert','red',condIsTrue ? 'up' : 'down'].join(' ')}>something...</p>

我使用rc-classnames包。

// ES6
import c from 'rc-classnames';

// CommonJS
var c = require('rc-classnames');

<button className={c('button', {
  'button--disabled': isDisabled,
  'button--no-radius': !hasRadius
})} />

你可以添加任何格式的类(数组,对象,参数)。数组或参数中的所有真值加上对象中等于true的键将合并在一起。

例如:

ReactClassNames('a', 'b', 'c') // => "a b c"
ReactClassNames({ 'a': true, 'b': false, c: 'true' }) // => "a c"
ReactClassNames(undefined, null, 'a', 0, 'b') // => "a b"

使用jbcn模块。(本支持)

https://www.npmjs.com/package/jbcn

例子:

const classNames = jbcn({ 
    btn: { 
        alpha: true, 
        beta: true, 
        gamma: false 
    } 
});

// ==> "btn btn--alpha btn--beta"
const classNames = jbcn({
    expand: true,
    hide: false,

    btn: { 
        alpha: true, 
        beta: true, 
        gamma: false 
    } 
});

// ==> "expand btn btn--alpha btn--beta"