I am in search of a way to determine if a div contains overflowing text and display a "show more" link if it does. While researching, I came across an insightful Stack Overflow answer on checking for overflow in a div. The answer suggests implementing a function that can access the styles of the element and perform checks to ascertain if it is overflowing. How can one access the styles of an element effectively? I attempted two different methods.
1. Utilizing ref
import React from "react";
import "./styles.css";
export default function App(props) {
const [showMore, setShowMore] = React.useState(false);
const onClick = () => {
setShowMore(!showMore);
};
const checkOverflow = () => {
const el = ref.current;
const curOverflow = el.style.overflow;
if (!curOverflow || curOverflow === "visible")
el.style.overflow = "hidden";
const isOverflowing = el.clientWidth < el.scrollWidth
|| el.clientHeight < el.scrollHeight;
el.style.overflow = curOverflow;
return isOverflowing;
};
const ref = React.createRef();
return (
<>
<div ref={ref} className={showMore ? "container-nowrap" : "container"}>
{props.text}
</div>
{checkOverflow() && <span className="link" onClick={onClick}>
{showMore ? "show less" : "show more"}
</span>}
</>
)
}
2. Using forward ref
Child component
export const App = React.forwardRef((props, ref) => {
const [showMore, setShowMore] = React.useState(false);
const onClick = () => {
setShowMore(!showMore);
};
const checkOverflow = () => {
const el = ref.current;
const curOverflow = el.style.overflow;
if (!curOverflow || curOverflow === "visible") el.style.overflow = "hidden";
const isOverflowing =
el.clientWidth < el.scrollWidth || el.clientHeight < el.scrollHeight;
el.style.overflow = curOverflow;
return isOverflowing;
};
return (
<>
<div ref={ref} className={showMore ? "container-nowrap" : "container"}>
{props.text}
</div>
{checkOverflow() && (
<span className="link" onClick={onClick}>
{showMore ? "show less" : "show more"}
</span>
)}
</>
);
});
Parent component
import React from "react";
import ReactDOM from "react-dom";
import { App } from "./App";
const rootElement = document.getElementById("root");
const ref = React.createRef();
ReactDOM.render(
<React.StrictMode>
<App
ref={ref}
text="Start editing to see some magic happen! Click show more to expand and show less to collapse the text"
/>
</React.StrictMode>,
rootElement
);
However, both approaches resulted in the error message -
Cannot read property 'style' of null