Resolving warning: “You provided ‘value’ prop to a form field without onChange handler” in React will be helpful for you when you make a form. Using onChange
attribute or removing value
attribute are usually the commonly used solutions. So how to do it? Let’s go into detail.
The reason for the warning: “You provided ‘value’ prop to a form field without onChange handler”
This warning happened because you made a static value for your form. Let’s see the example below:
import { useState } from 'react'; function App() { const [value, setValue] = useState('Hello From Learn Share IT'); return ( <div className="App"> <form> <h1></h1> <input type={'text'} value={value}></input> </form> </div> ); } export default App;
The warning:
Warning: You provided a `value` prop to a form field without an `onChange` handler. This will render a read-only field. If the field should be mutable, use `defaultValue`. Otherwise, set either `onChange` or `readOnly`.
at input
at form
at div
Here I get a warning because I set the value
attribue to the value
state without an onChange
handler, and the value
state is a static value. It means that the value in my input cannot change when the user interacts with UI. So React will recommend we use onChange
. Below are some solutions for this warning.
Solutions for this warning
Use onChange attribute
The obvious solution for this error is using the onChange
attribute for our input element. Then, every time input gets some new value. It can get logic to change the input value.
Example:
import { useState } from 'react'; function App() { const [value, setValue] = useState('Hello From Learn Share IT'); const handleValue = (e) => { setValue(e.target.value); }; return ( <div className="App"> <form> <input type={'text'} value={value} onChange={handleValue}></input> </form> </div> ); } export default App;
Output:
Here I make an onChange
and pass in the handleValue
function that sets the value
to the value
state every time the user changes the input value.
Remove value attribute
If you don’t want use the onChange
attribute and want to show the user some text, you can use it this way.
Use placeholder
import { useState } from 'react'; function App() { const [value, setValue] = useState('Type your name'); return ( <div className="App"> <form> <h1></h1> <input type={'text'} placeholder={value}></input> </form> </div> ); } export default App;
Output:
Here I make a placeholder
attribute to remind the user what this input is used for.
Use defaultValue
The input element also provided defaultValue
attribute to set a value as default for input.
Example:
import { useState } from 'react'; function App() { const [value, setValue] = useState('Type your name'); return ( <div className="App"> <form> <h1></h1> <input type={'text'} defaultValue={value}></input> </form> </div> ); } export default App;
Output:
Ignore the warning
You can ignore the warning if you know your purpose and what you are doing.
Summary:
In this article, I’ve shown you how to solve the warning: “You provided ‘value’ prop to a form field without onChange handler”. You can add an onChange
attribute, use defaultValue
or placeholder
attribute to follow your purpose. Or you can ignore it. Let’s try these methods!
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Hello, guys! I hope that my knowledge in HTML, CSS, JavaScript, TypeScript, NodeJS, ReactJS, MongoDB, Python, MySQL, and npm computer languages may be of use to you. I’m Brent Johnson, a software developer.
Name of the university: HOU
Major: IT
Programming Languages: HTML, CSS, JavaScript, TypeScript, NodeJS, ReactJS, MongoDB, PyThon, MySQL, npm