how to create a read more/less button in react-ag捕鱼王app官网

when building a web application, sometimes we need to display some long text. in this case, a smart design is to display only part of the text and add a show more button for the user to expand the text if needed. when the text is expanded and fully displayed, there is a show lessbutton to collapse it.

the complete example below shows you how to do this.

app preview

code

1. create a new react project:

$ npx create-react-app kindacode-example

a bunch of files and folders will be automatically generated. anyway, we only care about 2 files: src/app.js and src/app.css.

2. in src/app.js , we created a expandabletextreusable component called (we can put it in a separate file to keep things organized). this component can take 2 props: children (the text) and descriptionlength (the maximum number of characters to display initially). here is the full source code and explanation of src/app.js:

// jiyik.com
// src/app.js
import { usestate } from 'react';
import './app.css';

// createa reusable read more/less component
const expandabletext = ({ children, descriptionlength }) => {
  const fulltext = children;

  // set the initial state of the text to be collapsed
  const [isexpanded, setisexpanded] = usestate(false);

  // this function is called when the read more/less button is clicked
  const toggletext = () => {
    setisexpanded(!isexpanded);
  };

  return (
    <pclassname='text'>
      {isexpanded ? fulltext : `${fulltext.slice(0, descriptionlength)}...`}
      <spanonclick={toggletext}classname='toggle-button'>
        {isexpanded ? 'show less' : 'show more'}
      span>p>
  );
};

// main app
functionapp() {
  return (
    <><divclassname='container'><divclassname='card'><h1classname='title'>welcome to jiyik.comh1><p>
            {/* only show 120 characters in the beginning */}
            <expandabletextdescriptionlength={120}>
              lorem ipsum dolor sit amet, consectetur adipiscing elit. donec ut
              egestas mauris. maecenas leo mauris, accumsan vel velit ac,
              blandit lobortis est. vivamus in erat ac magna faucibus placerat
              eget non ligula. aliquam consequat rhoncus turpis a convallis.
              pellentesque ac sapien rhoncus, congue nibh eget, finibus turpis.
              aenean volutpat malesuada augue, at lacinia dolor volutpat congue.
              ut sit amet nunc ac arcu imperdiet iaculis. mauris sit amet quam
              ut nisi blandit blandit congue nec lorem. mauris viverra, quam non
              aliquet pellentesque, lorem risus fermentum mi, a mollis turpis
              velit vitae nulla. proin auctor, elit a rhoncus vulputate, est
              magna facilisis ipsum, non mattis sem odio in neque. cras at
              ultricies eros. ut risus turpis, consequat sed auctor nec, rutrum
              id mauris.
            expandabletext>p>div><divclassname='card'><h1classname='title'>just a dummy titleh1><p>
            {/* show 200 characters in the beginning */}
            <expandabletextdescriptionlength={200}>
              aliquam maximus, purus vel tempus luctus, libero ipsum consectetur
              purus, eu efficitur mi nunc sed purus. etiam tristique sit amet
              nisi vel rhoncus. vestibulum porta, metus sit amet tincidunt
              malesuada, dui sapien egestas magna, quis viverra turpis sapien a
              dolor. fusce ultrices eros eget tincidunt viverra. ut a dapibus
              erat, vel cursus odio. phasellus erat enim, volutpat vel lacus eu,
              aliquam sodales turpis. fusce ipsum ex, vehicula tempor accumsan
              nec, gravida at eros. in aliquam, metus id mollis interdum, nunc
              sem dignissim quam, non iaculis tortor erat nec eros. nunc
              sollicitudin ac dolor eget lobortis. aenean suscipit rutrum dolor
              in euismod. curabitur quis dapibus lectus. mauris enim leo,
              condimentum ac elit sit amet, iaculis vulputate sem.
            expandabletext>p>div>div>
  );
}
exportdefaultapp;

css is an important part of this demo. delete all the default code in src/app.css and add the following: /* src/app.css */

.container {
  width: 80%;
  margin: 50px auto;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
}

.card {
  width: 43%;
  padding: 15px 20px;
  background: #fffde7;
  box-shadow: 0 2px 4px 0 rgba(0, 0, 0, 0.2);
  border-radius: 10px;
}

.text {
  width: 100%;
}

/* style the read more/less button */
.toggle-button {
  margin-left: 7px;
  color: blue;
  cursor: pointer;
}

.toggle-button:hover {
  color: red;
  text-decoration: underline;
}

done. now let's get our application up and running and move on http://localhost:3000 to testing it.