How to add multiple classes to a ReactJS Component?

Question

I am new to ReactJS and JSX and I am having a little problem with the code below.

I am trying to add multiple classes to the className attribute on eac

Answer 1

You can create an element with multiple class names like this, I tryed these both way, its working fine...

If you importing any css then you can follow this way : Way 1:

import React, { Component, PropTypes } from 'react';
import csjs from 'csjs';
import styles from './styles';
import insertCss from 'insert-css';
import classNames from 'classnames';
insertCss(csjs.getCss(styles));
export default class Foo extends Component {
  render() {
    return (
      <div className={[styles.class1, styles.class2].join(' ')}>
        { 'text' }
      </div>
    );
  }
}

way 2:

import React, { Component, PropTypes } from 'react';
import csjs from 'csjs';
import styles from './styles';
import insertCss from 'insert-css';
import classNames from 'classnames';
insertCss(csjs.getCss(styles));
export default class Foo extends Component {
  render() {
    return (
      <div className={styles.class1 + ' ' + styles.class2}>
        { 'text' }
      </div>
    );
  }
}

**

If you applying css as internal :

const myStyle = {
  color: "#fff"
};

// React Element using Jsx
const myReactElement = (
  <h1 style={myStyle} className="myClassName myClassName1">
    Hello World!
  </h1>
);

ReactDOM.render(myReactElement, document.getElementById("app"));

.myClassName {
  background-color: #333;
  padding: 10px;
}
.myClassName1{
  border: 2px solid #000;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.4.0/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.4.0/umd/react-dom.production.min.js"></script>
<div id="app">
  
</div>

Answer 2

I use classnames when there is a fair amount of logic required for deciding the classes to (not) use. An overly simple example:

...
    var liClasses = classNames({
      'main-class': true,
      'activeClass': self.state.focused === index
    });

    return (<li className={liClasses}>{data.name}</li>);
...

That said, if you don't want to include a dependency then there are better answers below.

Answer 3

This can be achieved with ES6 template literals:

<input className={`class1 ${class2}`}>

Answer 4

When I have many varying classes, I have found the following to be useful.

The filter removes any of the null values and the join puts all the remaining values into a space separated string.

const buttonClasses = [
    "Button", 
    disabled ? "disabled" : null,
    active ? "active" : null
].filter((class) => class).join(" ")

<button className={buttonClasses} onClick={onClick} disabled={disabled ? disabled : false}>

Answer 5

You could do the following:

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

A short and simple solution, hope this helps.

Answer 6

I use ES6 template literals. For example:

const error = this.state.valid ? '' : 'error'
const classes = `form-control round-lg ${error}`

And then just render it:

<input className={classes} />

One-liner version:

<input className={`form-control round-lg ${this.state.valid ? '' : 'error'}`} />