清除和重置表单输入字段

The answer here depends on whether or not your inputs are controlled or uncontrolled. If you are unsure or need more info on this, check out what the official docs say about controlled components and uncontrolled components. Thanks @Dan-Esparza for providing the links.

Also, please note that using string literals in ref is deprecated. Use the standard callback method instead.

Clearing a form with uncontrolled fields

You can clear the entire form rather than each form field individually.

cancelCourse = () => {
document.getElementById("create-course-form").reset();
}


render() {
return (
<form id="create-course-form">
<input />
<input />
...
<input />
</form>
);
}

If your form didn't have an id attribute you could use a ref as well:

cancelCourse = () => {
this.myFormRef.reset();
}


render() {
return (
<form ref={(el) => this.myFormRef = el;}>
<input />
<input />
...
<input />
</form>
);
}

Clearing a form with controlled fields

If you are using controlled form fields, you may have to explicitly reset each component inside your form, depending on how your values are stored in the state.

If they are declared individually, you need to reset each one explicitly:

cancelCourse = () => {
this.setState({
inputVal_1: "",
inputVal_2: "",
...
inputVal_n: "",
});
}


render() {
return (
<input value={this.state.inputVal_1} onChange={this.handleInput1Change}>
<input value={this.state.inputVal_2} onChange={this.handleInput2Change}>
...
<input value={this.state.inputVal_n} onChange={this.handleInputnChange}>
);
}

Demo below:

class MyApp extends React.Component {
constructor() {
super();
this.state = {
inputVal_1: "",
inputVal_2: "",
inputVal_3: "",
inputVal_4: "",
inputVal_5: "",
inputVal_6: "",
inputVal_7: "",
inputVal_8: "",
inputVal_9: "",
inputVal_10: ""
};
}
  

handleInput1Change = (e) => {
this.setState({inputVal_1: e.target.value});
}
  

handleInput2Change = (e) => {
this.setState({inputVal_2: e.target.value});
}
  

handleInput3Change = (e) => {
this.setState({inputVal_3: e.target.value});
}
  

handleInput4Change = (e) => {
this.setState({inputVal_4: e.target.value});
}
  

handleInput5Change = (e) => {
this.setState({inputVal_5: e.target.value});
}
  

handleInput6Change = (e) => {
this.setState({inputVal_6: e.target.value});
}
  

handleInput7Change = (e) => {
this.setState({inputVal_7: e.target.value});
}
  

handleInput8Change = (e) => {
this.setState({inputVal_8: e.target.value});
}
  

handleInput9Change = (e) => {
this.setState({inputVal_9: e.target.value});
}
  

handleInput10Change = (e) => {
this.setState({inputVal_10: e.target.value});
}
  

cancelCourse = () => {
this.setState({
inputVal_1: "",
inputVal_2: "",
inputVal_3: "",
inputVal_4: "",
inputVal_5: "",
inputVal_6: "",
inputVal_7: "",
inputVal_8: "",
inputVal_9: "",
inputVal_10: ""
});
}
  

render() {
return (
<form>
<input value={this.state.inputVal_1} onChange={this.handleInput1Change} />
<input value={this.state.inputVal_2} onChange={this.handleInput2Change} />
<input value={this.state.inputVal_3} onChange={this.handleInput3Change} />
<input value={this.state.inputVal_4} onChange={this.handleInput4Change} />
<input value={this.state.inputVal_5} onChange={this.handleInput5Change} />
<input value={this.state.inputVal_6} onChange={this.handleInput6Change} />
<input value={this.state.inputVal_7} onChange={this.handleInput7Change} />
<input value={this.state.inputVal_8} onChange={this.handleInput8Change} />
<input value={this.state.inputVal_9} onChange={this.handleInput9Change} />
<input value={this.state.inputVal_10} onChange={this.handleInput10Change} />
<input type="submit" name="saveCourse" value="Create" />
<input type="button" name="cancelCourse" value="cancel" onClick={this.cancelCourse} />
</form>
);
}
}


ReactDOM.render(<MyApp />, document.getElementById("app"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="app"></div>

There is a cleaner way to do this though. Rather than having n state properties and n event handlers, one for each input, with some clever coding we can reduce the code dramatically.

In the constructor we just declare an empty object, which will be used to hold input values. We use only one input handler and pass it the index of the input element we want to change the value of. This means that the value of an individual input is generated the moment we start typing into it.

To reset the form, we only need to set our input object back to being empty again.

The input value is this.state.inputVal[i]. If i doesn't exist (we haven't typed anything yet into that input) we want the value to be an empty string (instead of null).

cancelCourse = () => {
this.setState({inputVal: {}});
}


render() {
return (
<form>
{[...Array(n)].map(
(item, i) => <input value={this.state.inputVal[i] || ""} onChange={this.handleInputChange.bind(this, i)} />
)}
</form>
);
}

Demo below:

class MyApp extends React.Component {
constructor() {
super();
this.state = {
inputVal: {}
};
}
  

handleInputChange = (idx, {target}) => {
this.setState(({inputVal}) => {
inputVal[idx] = target.value;
return inputVal;
});
}
  

cancelCourse = () => {
this.setState({inputVal: {}});
}
  

render() {
return(
<form>
{[...Array(10)].map(  //create an array with a length of 10
(item, i) => <input value={this.state.inputVal[i] || ""} onChange={this.handleInputChange.bind(this, i)} />  //bind the index to the input handler
)}
<input type="submit" name="saveCourse" value="Create" />
<input type="button" name="cancelCourse" value="cancel" onClick={this.cancelCourse} />
</form>
);
}
}


ReactDOM.render(<MyApp />, document.getElementById("app"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="app"></div>

Following code should reset the form in one click.

import React, { Component } from 'react';


class App extends Component {
constructor(props){
super(props);
this.handleSubmit=this.handleSubmit.bind(this);
}
handleSubmit(e){
this.refs.form.reset();
}
render(){
return(
<div>
<form onSubmit={this.handleSubmit} ref="form">
<input type="text" placeholder="First Name!" ref='firstName'/><br/<br/>
<input type="text" placeholder="Last Name!" ref='lastName'/><br/><br/>
<button type="submit" >submit</button>
</form>
</div>
}
}

Very easy:

handleSubmit(e){
e.preventDefault();
e.target.reset();
}

// If using class component
<form onSubmit={this.handleSubmit.bind(this)}>
...
</form>


// If using function component
<form onSubmit={handleSubmit}>
...
</form>

Good luck :)

To clear your form, admitted that your form's elements values are saved in your state, you can map through your state like that :

  // clear all your form
Object.keys(this.state).map((key, index) => {
this.setState({[key] : ""});
});

If your form is among other fields, you can simply insert them in a particular field of the state like that:

 state={
form: {
name:"",
email:""}
}


// handle set in nested objects
handleChange = (e) =>{
e.preventDefault();


const newState = Object.assign({}, this.state);
newState.form[e.target.name] = e.target.value;
this.setState(newState);
}


// submit and clear state in nested object
onSubmit = (e) =>{
e.preventDefault();


var form =   Object.assign({}, this.state.form);
Object.keys(form).map((key, index) => {
form[key] = "" ;
});


this.setState({form})
}

Using event.target.reset() only works for uncontrolled components, which is not recommended. For controlled components you would do something like this:

import React, { Component } from 'react'


class MyForm extends Component {
initialState = { name: '' }


state = this.initialState


handleFormReset = () => {
this.setState(() => this.initialState)
}


render() {


return (
<form onReset={this.handleFormReset}>
<div>
<label htmlFor="name">Name</label>
<input
type="text"
placeholder="Enter name"
name="name"
value={name}
onChange={this.handleInputOnChange}
/>
</div>
<div>
<input
type="submit"
value="Submit"
/>
<input
type="reset"
value="Reset"
/>
</div>
</form>
)
}
}


ContactAdd.propTypes = {}


export default MyForm

state={
name:"",
email:""
}


handalSubmit = () => {
after api call
let resetFrom = {}
fetch('url')
.then(function(response) {
if(response.success){
resetFrom{
name:"",
email:""
}
}
})
this.setState({...resetFrom})
}

I don't know if this is still relevant. But when I had similar issue this is how I resolved it.

Where you need to clear an uncontrolled form you simply do this after submission.

this.<ref-name-goes-here>.setState({value: ''});

Hope this helps.

You can also do it by targeting the current input, with anything.target.reset() . This is the most easiest way!

handleSubmit(e){
e.preventDefault();
e.target.reset();
}


<form onSubmit={this.handleSubmit}>
...
</form>

This one works best to reset the form.

import React, { Component } from 'react'
class MyComponent extends Component {
constructor(props){
super(props)
this.state = {
inputVal: props.inputValue
}
// preserve the initial state in a new object
this.baseState = this.state ///>>>>>>>>> note this one.
}
resetForm = () => {
this.setState(this.baseState) ///>>>>>>>>> note this one.
}
submitForm = () => {
// submit the form logic
}
updateInput = val => this.setState({ inputVal: val })
render() {
return (
<form>
<input
onChange={this.updateInput}
type="text
value={this.state.inputVal} />
<button
onClick={this.resetForm}
type="button">Cancel</button>
<button
onClick={this.submitForm}
type="submit">Submit</button>
</form>
)
}
}

/* See newState and use of it in eventSubmit() for resetting all the state. I have tested it is working for me. Please let me know for mistakes */

import React from 'react';
    

const newState = {
fullname: '',
email: ''
}
    

class Form extends React.Component {
constructor(props) {
super(props);
this.state = {
fullname: ' ',
email: ' '
}
    

this.eventChange = this
.eventChange
.bind(this);
this.eventSubmit = this
.eventSubmit
.bind(this);
}
eventChange(event) {
const target = event.target;
const value = target.type === 'checkbox'
? target.type
: target.value;
const name = target.name;
    

this.setState({[name]: value})
}
    

eventSubmit(event) {
alert(JSON.stringify(this.state))
event.preventDefault();
this.setState({...newState});
}
    

render() {
return (
<div className="container">
<form className="row mt-5" onSubmit={this.eventSubmit}>
<label className="col-md-12">
Full Name
<input
type="text"
name="fullname"
id="fullname"
value={this.state.fullname}
onChange={this.eventChange}/>
</label>
<label className="col-md-12">
email
<input
type="text"
name="email"
id="email"
value={this.state.value}
onChange={this.eventChange}/>
</label>
<input type="submit" value="Submit"/>
</form>
</div>
)
}
}
    

export default Form;
    

Why not use HTML-controlled items such as <input type="reset">

the easiest way is doing it regularly with just HTML and using the button type "reset" there is no need to mess with anything in react at all, no state, no nothing.

import React, {useState} from 'react'


function HowReactWorks() {
  

return (
<div>
<form>
<div>
<label for="name">Name</label>
<input type="text" id="name" placeholder="name" />
</div>
<div>
<label for="password">Password</label>
<input type="password" id="password" placeholder="password" />
</div>
<button type="reset">Reset</button>
<button>Submit</button>
</form>
</div>
)
}


export default HowReactWorks

• edited for the people that don't know how to include HTML in react

When the form is submitted, the 'event' will be passed as an argument to the handleSubmit method, and if that you can access the <form> element by typing event.target. then you just need to reset the form using .reset() form method.

https://developer.mozilla.org/en-US/docs/Web/API/HTMLFormElement/reset

  handleSubmit = (event)=>{
event.preventDefault()
....


event.target.reset()
}


render() {
return (
<>
<form onSubmit={this.handleSubmit}>
<label htmlFor='movieTitle'>Title</label>
<input name='movieTitle' id='movieTitle' type='text' />


<input type='submit' value='Find Movie Info' />
</form>
</>
)
}

You can use this method as well

const resetData = (e) => {
e.preventDefault();
settitle("");
setdate("");
};
    

<input type="text" onChange={(e) => settitle(e.target.value)} value={title} />
    

<input type="date" onChange={(e) => setdate(e.target.value)} value={date} />
    

<button onClick={resetData}>Reset Data</button>

This is the solution that worked for me, in the case of parent component triggering reset of child controlled input components:

const ParentComponent = () => {
const [reset, setReset] = useState()


const submitHandler = (e) => {
e.preventDefault()
//do your stuff
setReset(Date.now()) // pass some value to trigger update
}


return (
<form onSubmit={submitHandler}>
<ChildInputComponent reset={reset} />
<ChildInputComponent reset={reset} />
</form>
)
}


const ChildInputComponent = ({reset}) => {
const [value, setValue] = useState()


useEffect(() => {
setValue('')
}, [reset])


return <input value={value} onChange={(e) => setValue(e.target.value)} />
}

Here's an update to Chris's answer above, using modern React hooks.

Same high level idea; your form can be either a Controlled or Uncontrolled component.

Uncontrolled components:

Uncontrolled components leave state management up to the browser. That means you have to ask the browser to reset the form inputs. To do that, capture the form element as a ref, and then call the submit() method on that element.

export default function Form() {
const ref = React.useRef();


function reset(ev) {
ev.preventDefault();
ref.current.reset();
}


return (
<form ref={ref}>
<label htmlFor="email">Email Address</label>
<input id="email" type="email" name="email" />
<label htmlFor="message">Message</label>
<textarea id="message" name="message" />
<button type="submit">Submit</button>
<button onClick={reset}>Reset</button>
</form>
);
}

Controlled components:

With a controlled component, you manage the state in React. That means you have to create the initial state, and update it every time an input changes. In this world, resetting the form is just a matter of setting the form state back to its initial state.

export default function Form() {
const [state, setState] = React.useState({ email: "", message: "" });


function reset(ev) {
ev.preventDefault();
setState({ email: "", message: "" });
}


return (
<form className="Form">
<label htmlFor="email">Email Address</label>
<input
id="email"
type="email"
name="email"
value={state.email}
onChange={(ev) => {
setState({ ...state, email: ev.target.value });
}}
/>
<label htmlFor="message">Message</label>
<textarea
id="message"
name="message"
value={state.message}
onChange={(ev) => {
setState({ ...state, message: ev.target.value });
}}
/>
<button type="submit">Submit</button>
<button onClick={reset}>Reset</button>
</form>
);
}

Full example at https://codesandbox.io/s/reactformreset-10cjn3

Assuming you declared

const [inputs, setInputs] = useState([]);

As multiple parameters. You can actually reset the items using this syntax:

setInputs([]);

Just in case, this how you define handleChange.

You can use this form or any ways you want.

const handleChange = (event) => {
const name = event.target.name;
const email = event.target.email;
const message = event.target.message;
const value = event.target.value;
setInputs(values => ({...values, [name]: value, [email]: value, [message]: value}))
}

You can use this form as an example.

<form onSubmit={handleSubmit}>
<div className="fields">
<div className="field half">
<label for="name">Name</label>
<input value={inputs.name || ''} type="text" name="name" id="nameId" onChange={handleChange} maxLength="30" />
</div>
<div className="field half">
<label for="email">Email</label>
<input value={inputs.email || ''} type="text" name="email" id="emailId" onChange={handleChange} maxLength="40"/>
</div>
<div className="field">
<label for="message">Message</label>
<textarea value={inputs.message || ''} name="message" id="messageId" rows="6" onChange={handleChange} maxLength="400" />
</div>
</div>
<ul className="actions">
<li><input type="submit" value="Send Message" className="primary" /></li>
<li><input onClick={resetDetails} type="reset" value="Clear" /></li>
</ul>
</form>

This is just one of many ways to declare forms. Good luck!