How to add slick-active class in Slider dots in React Slick

Question

I used react-slick and made a carousel using Slider component. The code is bellow,

const carousel = (props) => {
    return (
        <div style={{ height: '50%', marginTop: '20px' }}>
            <Slider {...settings}>
                <div className={text__bar}>
                    <div >
                        <font>Lorum Ipsum 1</font>
                    </div>
                    <div className={slide1} />
                </div>
                <div className={text__bar}>
                    <div>
                        <font>Lorum Ipsum 2</font>
                    </div>
                    <div className={slide1} />
                </div>
                <div className={text__bar}>
                    <div>
                        <font>Lorum Ipsum 3</font>
                    </div>
                    <div className={slide1} />
                </div>
            </Slider>
            <div className={purple__bar}></div>
        </div>
    );
};

And the settings object,

const settings = {
    dots: true,
    infinite: true,
    speed: 500,
    slidesToShow: 1,
    slidesToScroll: 1,
    autoplay: true,
    autoplaySpeed: 5000,
    className: SlickMain,
    dotsClass: button__bar,
    arrows: false,
};

I have added some extra CSS to style my carousel dots (buttons) to look like bellow,

When examined by the developer tools the button related to the currently shown slide gets a CSS class injected named 'slick-active'

What I need to do is change the background color of the button corresponding to the slide, to black relapsing the current color purple.

What I did was,

.button__bar li.slick-active button {
    opacity: .75;
    color: #000
}

But it won't work. What am I missing?

.button__bar is the dotsClass I have given to dots in settings object.

Answer 1

This is happening because I'm using CSS-Modules to load my CSS file. In the following code example, you can clearly see what's happening.

https://codesandbox.io/s/1z2lnox5rq?fontsize=14

So as a solution what I did was adding bellow methods to settings object.

const settings = {
  dots: true,
  infinite: true,
  speed: 1000,
  slidesToShow: 1,
  slidesToScroll: 1,
  autoplay: true,
  autoplaySpeed: 3000,
  className: slickMain,
  dotsClass: button__bar,
  arrows: false,
  beforeChange: (prev, next) => {
    this.setState({ currentSlide: next });
  },
  // afterChange: (index) => this.setState({ currentSlide: index }),
  appendDots: dots => {
    return (
      <div>
        <ul>
          {dots.map((item, index) => {
            return (
              <li key={index}>{item.props.children}</li>
            );
          })}
        </ul>
      </div>
    )
  },
  customPaging: index => {
    return (
      <button style={index === this.state.currentSlide ? testSettings : null}>
        {index + 1}
      </button>
    )
  }
};

To solve my problem, I used beforeChange to acquire the next slide index and saved it in the state. Then using appendDots a div with a ul, li is injected to the dot-bar section which. Inside the li, a button passed as a child prop using customPaging method. When the current slide equals the index of the customPaging, which is in the state, then a class is injected with a background color.

const testSettings = {
    backgroundColor: 'rgba(255, 255, 255, 0.8)',
    outline: '0'
}

Answer 2

In case someone is using material ui here is how it could work

const settings: Settings = {
  dots: true,
  infinite: true,
  speed: 500,
  slidesToShow: 1,
  slidesToScroll: 1,
  dotsClass: `slick-dots ${classes.dots}`,
};
// your classes created with material ui
makeStyles((theme: Theme) => ({
// may not be the best way but it works
  dots: {
    bottom: 0,
    "& li.slick-active button::before": {
      color: theme.palette.primary.main,
    },
    "& li": {
      "& button::before": {
      fontSize: theme.typography.pxToRem(14),
      color: "#fff",
      opacity: 0.5,
    },
  }
}))

Here is a codesandbox link https://codesandbox.io/s/bold-snow-h9rwq?file=/src/App.tsx

Please note, that I haven't checked it with importing slick css i.e.

// Import css files
import "slick-carousel/slick/slick.css";
import "slick-carousel/slick/slick-theme.css";

but used cdn instead