在浏览器后退按钮上滚动到顶部单击反应

Question

I need to scroll to the top every time the URL changes in my project (and on page reload).

Everything is working but I am having a problem with the browser back button. Even if the pathname changes the page doesn't scroll to the top as it should, it works on all other cases (page reload and regular link navigation).

I tried to counter that by creating a custom hook just for the back button, but it's not behaving how I want. I also tried a bunch of other things, but nothing seems to work as for the browser back button

import { useEffect, useState } from "react";
import { useLocation } from "react-router-dom";

const ScrollToTop = () => {
  const { pathname } = useLocation();

  const useBackButton = () => {
    const [isBack, setIsBack] = useState(false);
    const handleEvent = () => {
      setIsBack(true);
    };
    useEffect(() => {
      window.addEventListener("popstate", handleEvent);
      return () => window.removeEventListener("popstate", handleEvent);
    });
    return isBack;
  };

  const backButton = useBackButton();
  console.log(backButton);

  useEffect(() => {
    window.scrollTo(0, 0);
  }, [pathname, backButton]);

  useEffect(() => {
    window.onbeforeunload = () => {
      window.scrollTo(0, 0);
    };
  }, []);

  return null;
};

export default ScrollToTop;

Answer 1

I don't think the beforeunload event is necessary here, but will include it anyway. Instead of using an event listener for the "popstate" event you can use the useNavigationType hook to expressly check for a POP event type.

Note : Use window.addEventListener for the beforeunload event so you don't pollute/mutate the window object.

Example:

import { NavigationType, useLocation, useNavigationType } from "react-router-dom";

const useBackButton = () => {
  const navType = useNavigationType();
  return navType === NavigationType.Pop;
};

const useScrollToTop = () => {
  const { pathname } = useLocation();

  const isPop = useBackButton();

  const scrollToTop = () => window.scrollTo(0, 0);

  useEffect(() => {
    scrollToTop();
  }, [pathname, isPop]);

  useEffect(() => {
    window.addEventListener("beforeunload", scrollToTop);
    return () => {
      window.removeEventListener("beforeunload", scrollToTop);
    };
  }, []);
};

Usage:

function App() {
  useScrollToTop();

  return (
    ...
  );
}

Answer 2

Here is my solution using React hooks:

const [showsScrolBtn, setShowScrolBtn] = useState(false);

useEffect(() => {
  const handleButtonVisibility = () => {
    window.pageYOffset > 300 ? setShowScrolBtn(true) : setShowScrolBtn(false);
  };

  window.addEventListener("scroll", handleButtonVisibility);
  return () => {
    window.addEventListener("scroll", handleButtonVisibility);
  };
}, []);

{
  showsScrolBtn && (
    <div
      id="scrolToTop"
      onClick={() => {
        window.scrollTo({
          top: 0,
          left: 0,
          behavior: "smooth",
        });
      }}
      style={{
        position: "fixed",
        bottom: "60px",
        right: "60px",
        color: "gray",
        textAlign: "center",
        cursor: "pointer",
        fontSize: "4em",
        lineHeight: 0,
        textDecoration: "none",
      }}
    >
      Click To Move Top
    </div>
  );
}