React useHash Hook

Introduction

In this lab, we will learn how to use the useHash hook in React to track and update the browser's location hash value. This hook is useful for creating single-page applications where different components or sections of the page are displayed based on the hash value. By the end of this lab, you will be able to implement the useHash hook in your React projects and enhance the user experience of your web applications.

React useHash Hook

index.html and script.js have already been provided in the VM. In general, you only need to add code to script.js and style.css.

This code tracks and updates the browser's location hash value. To use it, follow these steps:

1. Use the useState() hook to lazily get the hash property of the Location object.
2. Use the useCallback() hook to create a handler that updates the hash state when the 'hashchange' event is fired.
3. Use the useEffect() hook to add a listener for the 'hashchange' event when mounting and clean it up when unmounting.
4. Use the useCallback() hook to create a function that updates the hash property of the Location object with the given value.
5. In your component, call useHash() to get the current hash value and an updateHash() function to change it.
6. Use the updateHash() function to change the hash value.
7. Render the current hash value in a component.
8. Create an input field that allows the user to change the hash value.

Here's the code:

const useHash = () => {
  const [hash, setHash] = React.useState(() => window.location.hash);

  const hashChangeHandler = React.useCallback(() => {
    setHash(window.location.hash);
  }, []);

  React.useEffect(() => {
    window.addEventListener("hashchange", hashChangeHandler);
    return () => {
      window.removeEventListener("hashchange", hashChangeHandler);
    };
  }, []);

  const updateHash = React.useCallback(
    (newHash) => {
      if (newHash !== hash) window.location.hash = newHash;
    },
    [hash]
  );

  return [hash, updateHash];
};

const MyApp = () => {
  const [hash, setHash] = useHash();

  React.useEffect(() => {
    setHash("#list");
  }, []);

  return (
    <>
      <p>Current hash value: {hash}</p>
      <p>Edit hash: </p>
      <input value={hash} => setHash(e.target.value)} />
    </>
  );
};

ReactDOM.createRoot(document.getElementById("root")).render(<MyApp />);

Please click on 'Go Live' in the bottom right corner to run the web service on port 8080. Then, you can refresh the Web 8080 Tab to preview the web page.

Summary

Congratulations! You have completed the React useHash Hook lab. You can practice more labs in LabEx to improve your skills.