Category: React Answers

Sometimes, we want to clear an input field with React.

In this article, we’ll look at how to clear an input field with React.

Clear an Input Field with React

To clear an input field with React, we can set the state that’s used as the input value to an empty string.

For instance, we can write:

import React, { useState } from "react";

export default function App() {
  const [firstName, setFirstName] = useState("");

  const handleSubmit = (e) => {
    e.preventDefault();
    if (firstName) {
      console.log(firstName);
      setFirstName("");
    }
  };

  return (
    <>
      <form onSubmit={handleSubmit}>
        <label htmlFor="firstName">Name </label>
        <input
          type="text"
          value={firstName}
          onChange={(e) => setFirstName(e.target.value)}
        />
        <button type="submit">add person</button>
      </form>
    </>
  );
}

We have the firstName state that we created with the useState hook. It’s set as the value of the value prop of the input.

Then we have the handleSubmit function that calls e.preventDefault to prevent server-side form submission.

And we call setFirstName with an empty string to clear the input.

Next, we have an input with the onChange prop set to a function that calls setFirstName with e.target.value to set the firstName state to the inputted value.

And we set onSubmit prop to handleSubmit to call it when we click on the button.

Conclusion

To clear an input field with React, we can set the state that’s used as the input value to an empty string.

Sometimes, we want to use the clsx Library to set class names dynamically in React.

In this article, we’ll look at how to use the clsx Library to set class names dynamically in React.

Use the Clsx Library to Set Class Names Dynamically in React

To use the clsx Library to set class names dynamically in React, we call the clsx function with an object that has the class names as the property names.

And the values of the properties would be the condition of which the class names will be applied.

For instance, we can write:

import clsx from "clsx";
import React from "react";

const menuStyle = clsx({
  root: true,
  menuOpen: false
});

export default function App() {
  return <div className={menuStyle}></div>;
}

We call clsx with:

{
  root: true,
  menuOpen: false
}

to add the root class and skip the menuOpen class.

We pass the returned string as the value of the className prop to set the class names.

Conclusion

To use the clsx Library to set class names dynamically in React, we call the clsx function with an object that has the class names as the property names.

And the values of the properties would be the condition of which the class names will be applied.

Sometimes, we want to update meta tags in React.

In this article, we’ll look at how to update meta tags in React.

Update Meta Tags in React

To update meta tags in React, we can use the react-document-meta library.

To install it, we run:

npm i react-document-meta

Then we can change the meta tags by writing:

import React from "react";
import DocumentMeta from "react-document-meta";

const meta = {
  title: "Some Meta Title",
  description: "I am a description, and I can create multiple tags",
  canonical: "http://example.com/path/to/page",
  meta: {
    charset: "utf-8",
    name: {
      keywords: "react,meta,document,html,tags"
    }
  }
};

export default function App() {
  return (
    <div>
      <DocumentMeta {...meta} />
    </div>
  );
}

We set the title meta tag with the title property.

We set the description meta tag with the description property.

We set the canonical meta tag with the canonical property.

And we set the other meta tags with the meta property.

We spread the meta object as the props for the DocumentMeta component to set the meta tags.

Conclusion

To update meta tags in React, we can use the react-document-meta library.

Sometimes, we want to cancel or abort ajax requests in Axios in a React app.

In this article, we’ll look at how to cancel or abort ajax requests in Axios in a React app.

Cancel or Abort Ajax Requests in Axios in a React App

To cancel or abort ajax requests in Axios in a React app, we can use the Axios cancel token feature.

For instance, we can write:

import React, { useRef, useState } from "react";
import axios from "axios";

export default function App() {
  const [answer, setAnswer] = useState({});
  const cancelTokenSource = useRef();

  const request = async () => {
    try {
      setAnswer({});
      cancelTokenSource.current = axios.CancelToken.source();
      const { data } = await axios.get("https://yesno.wtf/api", {
        cancelToken: cancelTokenSource.current.token
      });
      setAnswer(data);
    } catch (error) {
      console.log(error);
    }
  };

  const cancel = () => {
    cancelTokenSource.current.cancel();
  };

  return (
    <div>
      <button onClick={request}>request</button>
      <button onClick={cancel}>cancel</button>
      <div>{JSON.stringify(answer)}</div>
    </div>
  );
}

We define the answer state to store the request response.

And we have the cancelTokenSource ref to store the cancellation token.

In the request function, we set the cancelTokenSource.current to the axios.CancelToken.source() which returns the cancel token object.

And then when we make the request with axios.get , we set cancelToken to the cancel token.

Next, we get the data and set it to answer .

Then we define the cancel function that calls the cancel method that comes with the cancel token to cancel the request.

Conclusion

To cancel or abort ajax requests in Axios in a React app, we can use the Axios cancel token feature.

Sometimes, we want to check if the React component is unmounted.

In this article, we’ll look at how to check if the React component is unmounted.

Check if the React Component is Unmounted

To check if the React component is unmounted, we can set a state in the callback that’s returned in the useEffect hook callback.

For instance, we can write:

import React, { useEffect, useState } from "react";

export default function App() {
  const [isMounted, setIsMounted] = useState(false);

  useEffect(() => {
    setIsMounted(true);
    return () => setIsMounted(false);
  }, []);
  return <div>{isMounted.toString()}</div>;
}

We create the isMounted state with the useState hook.

Then we call the useEffect hook with a callback that calls setIsMounted to set isMounted to true .

And since the function that’s returned in the useEffect callback runs when the component unmounts, we can call setIsMounted to set isMounted to false there.

Finally, we render the value of isMounted is the div.

Conclusion

To check if the React component is unmounted, we can set a state in the callback that’s returned in the useEffect hook callback.