React onSubmit placement - reactjs

I have looked at multiple sources for using onSubmit functions in React and they always place onSubmit triggers as a Form attribute, like this
import React, { Component } from "react";
import { connect } from "react-redux";
import PropTypes from "prop-types";
import { register } from "../../../actions/auth/auth.action";
import { Container } from "react-bootstrap";
import {
Button,
Form,
Label,
Input,
} from "reactstrap";
class Register extends Component {
state = {
fname: "",
lname: "",
email: "",
password: ""
};
static propTypes = {
register: PropTypes.func.isRequired
};
handleChange = e => {
this.setState({
[e.target.name]: e.target.value
});
};
handleSubmit = e => {
e.preventDefault();
const { fname, lname, email, password } = this.state;
const newUser = {
name: {
first: fname,
last: lname
},
email: {
address: email
},
password
};
// Attempt to register user
this.props.register(newUser);
};
render() {
return(
<Form onSubmit={this.handleSubmit}>
<Label for="fname">First Name</Label>
<Input
type="text"
name="fname"
id="fname"
placeholder="Enter first name"
className="mb-3"
onChange={this.handleChange}
/>
<Label for="lname">Last Name</Label>
<Input
type="text"
name="lname"
id="lname"
placeholder="Enter last name"
className="mb-3"
onChange={this.handleChange}
/>
<Label for="email">Email</Label>
<Input
type="email"
name="email"
id="email"
placeholder="Enter email"
className="mb-3"
onChange={this.handleChange}
/>
<Label for="password">Password</Label>
<Input
type="password"
name="password"
id="password"
placeholder="Enter password"
className= "mb-3"
onChange={this.handleChange}
/>
<Button color="primary" style={{ marginTop: "2rem" }} block>
Register
</Button>
</Form>
);
};
};
const mapStateToProps = state => ({
error: state.error
});
export default connect(
mapStateToProps,
{ register }
)
(Register);
However, when I try this there is no way to call the function. (Ie. how does the button "know" when to call the onSubmit function when the call is a Form attrbute) I even tried added a type="submit" attribute to the button but that doesn't work either.

Just declare type="submit" in your button <button type="submit">send stuff</button> The type attribute is what onSubmit form is waiting for :) and remove e.preventDefault from your handleSubmit method and try again

The function will be called when submit event occurred.
Below code shows actions that trigger submit event.
class FormComponent extends React.Component {
handleSubmit = e => {
e.preventDefault();
console.log('submitted');
}
render() {
return (
<form onSubmit={this.handleSubmit}>
<input type="submit" /><br />
<button>Button with no attribute</button><br />
<button type="submit">submit typed Button</button><br />
<button type="button">button typed Button (no submit)</button><br />
<input type="text" value="Press enter to submit" />
</form>
);
}
}
ReactDOM.render(
<FormComponent />,
document.getElementById("react")
);
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.4/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.4/umd/react-dom.production.min.js"></script>
<div id="react"></div>

Related

How to use useFormik hook with async await in onSubmit event?

I'm trying to find how to use async-await with useFormik hooks in onSubmit event.
I want to use axios library inside onSubmit event but with async await, but I'm not able to find the way how to use async await inside onSubmit event.
import React from 'react';
import { useFormik } from 'formik';
const SignupForm = () => {
const formik = useFormik({
initialValues: {
firstName: '',
lastName: '',
email: '',
},
onSubmit: values => {
alert(JSON.stringify(values, null, 2));
},
});
return (
<form onSubmit={formik.handleSubmit}>
<label htmlFor="firstName">First Name</label>
<input
id="firstName"
name="firstName"
type="text"
onChange={formik.handleChange}
value={formik.values.firstName}
/>
<label htmlFor="lastName">Last Name</label>
<input
id="lastName"
name="lastName"
type="text"
onChange={formik.handleChange}
value={formik.values.lastName}
/>
<label htmlFor="email">Email Address</label>
<input
id="email"
name="email"
type="email"
onChange={formik.handleChange}
value={formik.values.email}
/>
<button type="submit">Submit</button>
</form>
);
};
The onSubmit event receives a callback function, it can be a normal function or async function:
...
onSubmit: async (values) => {
// await something here...
},
...
Declare your "await" inside onSubmit function, and then call the api using axios after "await" keyword.
EXAMPLE: https://codesandbox.io/s/jovial-wescoff-uh2e3b
CODE:
import React from "react";
import ReactDOM from "react-dom";
import { Formik, Field, Form } from "formik";
import axios from "axios";
const Example = () => (
<div>
<h1>Sign Up</h1>
<Formik
initialValues={{
firstName: "",
lastName: "",
email: "",
password: ""
}}
onSubmit={async (values) => {
const user = await axios.get("https://reqres.in/api/login", {
email: values.email,
password: values.password
});
alert(JSON.stringify(user, null, 2));
}}
>
{({ isSubmitting }) => (
<Form>
<label htmlFor="firstName">First Name</label>
<Field name="firstName" placeholder="Eve" />
<label htmlFor="lastName">Last Name</label>
<Field name="lastName" placeholder="Holt" />
<label htmlFor="email">Email</label>
<Field name="email" placeholder="eve.holt#reqres.in" type="email" />
<label htmlFor="password">Password</label>
<Field name="password" placeholder="cityslicka" type="password" />
<button type="submit" disabled={isSubmitting}>
Submit
</button>
</Form>
)}
</Formik>
</div>
);
ReactDOM.render(<Example />, document.getElementById("root"));

React JS Form button calling

I am try trying to submit the form once the button is clicked, but the function is not triggering in React.
The only enquiry is on the submit button onclick=submitform.
So I can get the value and update it to the json arry
import React, { Component } from "react";
class Createcomponent extends Component {
constructor() {
super()
this.state={
firstname:"",
lastname:"",
phonenumber:""
}
this.ontextchange=this.ontextchange.bind(this)
this.submitform=this.submitform.bind(this)
}
componentDidMount() {
console.log("Component Mounted");
}
ontextchange(event) {
if(event.target.id==='fname') {
this.setState({firstname: event.target.value})
}
}
submitform() {
alert("trigger");
//console.log(this.state)
}
render(){
return (
<div>
<label for="fname">First name:</label>
<input type="text" id="fname" onChange={this.ontextchange} value={this.state.firstname} name="fname"/><br/>
<label for="lname">Last name:</label>
<input type="text" id="lname" onChange={this.ontextchange} value={this.state.lastname} name="lname"/><br/>
<label for="lname">PhoneNumber:</label>
<input type="text" id="phone" onChange={this.ontextchange} value={this.state.phonenumber} name="lname"/><br/>
<input type="submit" value="Submit"/>
<button onClick={this.submitform}>Submit</button>
</div>
);
}
}
export default Createcomponent
You have two "Submit" buttons. Clicking the right "Submit" button triggers the alert correctly using your code as it is.
The left "Submit" button, which is setup as a form submit by setting type = submit, doesn't do anything because there actually is no <form> in use. Setting up a form as I've added it to your code below, the left "Submit" button works too. I've also created this CodeSandbox for demonstration.
import React, { Component } from "react";
class Createcomponent extends Component {
constructor() {
super();
this.state = {
firstname: "",
lastname: "",
phonenumber: ""
};
this.ontextchange = this.ontextchange.bind(this);
this.submitform = this.submitFormButton.bind(this);
}
componentDidMount() {
console.log("Component Mounted");
}
ontextchange(event) {
if (event.target.id === "fname") {
this.setState({ firstname: event.target.value });
}
}
submitFormButton() {
alert("trigger");
//console.log(this.state)
}
submitFormOnSubmit(e) {
e.preventDefault();
alert("trigger");
}
render() {
return (
<form onSubmit={this.submitFormOnSubmit}>
<label for="fname">First name:</label>
<input
type="text"
id="fname"
onChange={this.ontextchange}
value={this.state.firstname}
name="fname"
/>
<br />
<label for="lname">Last name:</label>
<input
type="text"
id="lname"
onChange={this.ontextchange}
value={this.state.lastname}
name="lname"
/>
<br />
<label for="lname">PhoneNumber:</label>
<input
type="text"
id="phone"
onChange={this.ontextchange}
value={this.state.phonenumber}
name="lname"
/>
<br />
<input type="submit" value="Submit" />
<button onClick={this.submitFormButton}>Submit</button>
</form>
);
}
}
export default Createcomponent;
Make sure to use htmlFor instead of for in React on your label element.

Semantic UI React (SUIR) Form with only a Form.Dropdown won't submit on Enter

I am trying to build a form with a dropdown and a submit button with SUIR. The form is submitted when I click the button but not when I press Enter.
<Form onSubmit={this.onSubmit}>
<Button type='submit'>
Submit
</Button>
<Form.Dropdown
fluid
selection
options={options}
onChange={onChange}
value={value}
/>
</Form>
What is the best way to get both to work ?
You can add an event Listener "keydown":
If your are developing Function component with hooks api you can do something like:
import { Button, Checkbox, Form } from "semantic-ui-react";
import { useEffect } from "react";
const MyForm = () => {
useEffect(() => {
const handleKeyDown = (event) => {
if (event.keyCode === 13) {
//13 is the Enter key code
onSubmit();
}
};
document.addEventListener("keydown", handleKeyDown);
return () => {
document.removeEventListener("keydown", handleKeyDown);
};
}, []);
function onSubmit() {
console.log("submit function");
}
return (
<Form onSubmit={onSubmit}>
<Form.Field>
<label>First Name</label>
<input placeholder="First Name" />
</Form.Field>
<Form.Field>
<label>Last Name</label>
<input placeholder="Last Name" />
</Form.Field>
<Form.Field>
<Checkbox label="I agree to the Terms and Conditions" />
</Form.Field>
<Button type="submit">Submit</Button>
</Form>
);
};
export default MyForm;
Or if you are using class component :
import "./styles.css";
import "semantic-ui-css/semantic.min.css";
import { Button, Checkbox, Form } from "semantic-ui-react";
import React from "react";
export default class FormClass extends React.Component {
onSubmit() {
console.log("submit class");
}
handleKeyDown = (event) => {
if (event.keyCode === 13) {
//13 is the Enter key code
this.onSubmit();
}
};
componentDidMount() {
document.addEventListener("keydown", this.handleKeyDown);
}
componentWillUnmount() {
document.removeEventListener("keydown", this.handleKeyDown);
}
render() {
return (
<Form onSubmit={this.onSubmit}>
<Form.Field>
<label>First Name</label>
<input placeholder="First Name" />
</Form.Field>
<Form.Field>
<label>Last Name</label>
<input placeholder="Last Name" />
</Form.Field>
<Form.Field>
<Checkbox label="I agree to the Terms and Conditions" />
</Form.Field>
<Button type="submit">Submit</Button>
</Form>
);
}
}
An other solution is to use the onKeyPressprops this solution add another feature that to be execute on key the component need to be focus (the two other solution add an eventListner on all the document):
for example in a Class component (works too in a function component):
export default class FormClassKeyPress extends React.Component {
onSubmit() {
console.log("submit class on key press");
}
handleKeyDown = (event) => {
if (event.keyCode === 13) {
//13 is the Enter key code
this.onSubmit();
}
};
render() {
return (
<Form onSubmit={this.onSubmit} onKeyPress={this.handleKeyDown}>
<Form.Field>
<label>First Name</label>
<input placeholder="First Name" />
</Form.Field>
<Form.Field>
<label>Last Name</label>
<input placeholder="Last Name" />
</Form.Field>
<Form.Field>
<Checkbox label="I agree to the Terms and Conditions" />
</Form.Field>
<Button type="submit">Submit</Button>
</Form>
);
}
}
here you can see a codeSandbox example of both component type and onKeyPress

Open a new component when the register button is clicked

Open as a new page and the user goes inside the page when the button is clicked. How can I do it in react functional component? I want to navigate from Register to another MyProfile component when button is clicked. The code for Register component is as below:
import React, { useState } from 'react'
import './Register.css'
import axios from 'axios'
import { useHistory } from 'react-router-dom'
function Register() {
const history = useHistory();
const [data, setData] = useState({
name: "",
email: "",
password: "",
confirmpassword: "",
});
const register = (e) => {
e.preventDefault();
history.push("/myprofile")
}
const InputEvent = (event) => {
const { name, value } = event.target;
setData((preVal) => {
return {
...preVal,
[name]: value,
};
});
};
const formSubmit = (e) => {
e.preventDefault();
};
return (
<div className="signup__container">
<div className="signup__containerInfo">
<h1 className="h1__swari">swari</h1>
<hr />
</div>
<form4 onSubmit={formSubmit}>
<h5 className="h5__form"> Name</h5>
<input type="text" placeholder="Full Name" name="name" value={data.name} onChange={InputEvent} />
<h5 className="h5__form"> Email-Address </h5>
<input type="Email" placeholder="Email" name="email" value={data.email} onChange={InputEvent} />
<h5 className="h5__form"> Password </h5>
<input type="Password" placeholder="Password" name="password" value={data.password} onChange={InputEvent} />
<h5 className="h5__form"> Confirm Password </h5>
<input type="Password" placeholder="Confirm Password" name="confirmpassword" value={data.confirmpassword} onChange={InputEvent} />
<p>
<button onClick={register} type="submit" className="signup__registerButton" >Register Now</button>
</p>
</form4>
</div>
)
}
export default Register
Make a separate component of History.js
import { createBrowserHistory } from 'history';
export default createBrowserHistory();
Then in Register component.
import history from "../Shared/history";
const formSubmit = e => {
e.preventDefault();
history.push("/SomeComponent", {
someData: true,
otherData:{},
});
};
In Routes:
<Route path="/SomeComponent" component={Component} />

Get form data in React

I have a simple form in my render function, like so:
render : function() {
return (
<form>
<input type="text" name="email" placeholder="Email" />
<input type="password" name="password" placeholder="Password" />
<button type="button" onClick={this.handleLogin}>Login</button>
</form>
);
},
handleLogin: function() {
// How can I access email and password here?
}
What should I write in my handleLogin: function() { ... } to access Email and Password fields?
There are a few ways to do this:
1) Get values from array of form elements by index
handleSubmit = (event) => {
event.preventDefault();
console.log(event.target[0].value)
}
2) Using name attribute in html
handleSubmit = (event) => {
event.preventDefault();
console.log(event.target.elements.username.value) // from elements property
console.log(event.target.username.value) // or directly
}
<input type="text" name="username"/>
3) Using refs
handleSubmit = (event) => {
console.log(this.inputNode.value)
}
<input type="text" name="username" ref={node => (this.inputNode = node)}/>
Full example
class NameForm extends React.Component {
handleSubmit = (event) => {
event.preventDefault()
console.log(event.target[0].value)
console.log(event.target.elements.username.value)
console.log(event.target.username.value)
console.log(this.inputNode.value)
}
render() {
return (
<form onSubmit={this.handleSubmit}>
<label>
Name:
<input
type="text"
name="username"
ref={node => (this.inputNode = node)}
/>
</label>
<button type="submit">Submit</button>
</form>
)
}
}
Use the change events on the inputs to update the component's state and access it in handleLogin:
handleEmailChange: function(e) {
this.setState({email: e.target.value});
},
handlePasswordChange: function(e) {
this.setState({password: e.target.value});
},
render : function() {
return (
<form>
<input type="text" name="email" placeholder="Email" value={this.state.email} onChange={this.handleEmailChange} />
<input type="password" name="password" placeholder="Password" value={this.state.password} onChange={this.handlePasswordChange}/>
<button type="button" onClick={this.handleLogin}>Login</button>
</form>);
},
handleLogin: function() {
console.log("EMail: " + this.state.email);
console.log("Password: " + this.state.password);
}
Working fiddle.
Also, read the docs, there is a whole section dedicated to form handling: Forms
Previously you could also use React's two-way databinding helper mixin to achieve the same thing, but now it's deprecated in favor of setting the value and change handler (as above):
var ExampleForm = React.createClass({
mixins: [React.addons.LinkedStateMixin],
getInitialState: function() {
return {email: '', password: ''};
},
handleLogin: function() {
console.log("EMail: " + this.state.email);
console.log("Password: " + this.state.password);
},
render: function() {
return (
<form>
<input type="text" valueLink={this.linkState('email')} />
<input type="password" valueLink={this.linkState('password')} />
<button type="button" onClick={this.handleLogin}>Login</button>
</form>
);
}
});
Documentation is here: Two-way Binding Helpers.
Adding on to Michael Schock's answer:
class MyForm extends React.Component {
constructor() {
super();
this.handleSubmit = this.handleSubmit.bind(this);
}
handleSubmit(event) {
event.preventDefault();
const data = new FormData(event.target);
console.log(data.get('email')); // Reference by form input's `name` tag
fetch('/api/form-submit-url', {
method: 'POST',
body: data,
});
}
render() {
return (
<form onSubmit={this.handleSubmit}>
<label htmlFor="username">Enter username</label>
<input id="username" name="username" type="text" />
<label htmlFor="email">Enter your email</label>
<input id="email" name="email" type="email" />
<label htmlFor="birthdate">Enter your birth date</label>
<input id="birthdate" name="birthdate" type="text" />
<button>Send data!</button>
</form>
);
}
}
See this Medium article: How to Handle Forms with Just React
This method gets form data only when the Submit button is pressed. It is much cleaner, IMO!
For those who don't want to use ref and reset the state with OnChange event, you can just use simple OnSubmit handle and loop through the FormData object.
Note that you cannot access formData.entries() directly since it is an iterable, you have to loop over it.
This example is using React Hooks:
const LoginPage = () => {
const handleSubmit = (event) => {
const formData = new FormData(event.currentTarget);
event.preventDefault();
for (let [key, value] of formData.entries()) {
console.log(key, value);
}
};
return (
<div>
<form onSubmit={handleSubmit}>
<input type="text" name="username" placeholder="Email" />
<input type="password" name="password" placeholder="Password" />
<button type="submit">Login</button>
</form>
</div>
);
};
And if you're using TypeScript:
export const LoginPage: React.FC<{}> = () => {
const handleSubmit: React.FormEventHandler<HTMLFormElement> = (event) => {
const formData = new FormData(event.currentTarget);
event.preventDefault();
for (let [key, value] of formData.entries()) {
console.log(key, value);
}
};
return (
<div>
<form onSubmit={handleSubmit}>
<input type="text" name="username" placeholder="Email" />
<input type="password" name="password" placeholder="Password" />
<button type="submit">Login</button>
</form>
</div>
);
};
An alternative approach is to use the ref attribute and reference the values with this.refs. Here is a simple example:
render: function() {
return (<form onSubmit={this.submitForm}>
<input ref="theInput" />
</form>);
},
submitForm: function(e) {
e.preventDefault();
alert(React.findDOMNode(this.refs.theInput).value);
}
More info can be found in the React docs:
https://facebook.github.io/react/docs/more-about-refs.html#the-ref-string-attribute
For a lot of the reasons described in How do I use radio buttons in React? this approach isn't always the best, but it does present a useful alternative in some simple cases.
There isn't any need to use refs. You can access it using an event:
function handleSubmit(e) {
e.preventDefault()
const {username, password } = e.target.elements
console.log({username: username.value, password: password.value })
}
<form onSubmit={handleSubmit}>
<input type="text" id="username"/>
<input type="text" id="password"/>
<input type="submit" value="Login" />
</form>
An easy way to deal with refs:
class UserInfo extends React.Component {
constructor(props) {
super(props);
this.handleSubmit = this.handleSubmit.bind(this);
}
handleSubmit(e) {
e.preventDefault();
const formData = {};
for (const field in this.refs) {
formData[field] = this.refs[field].value;
}
console.log('-->', formData);
}
render() {
return (
<div>
<form onSubmit={this.handleSubmit}>
<input ref="phone" className="phone" type='tel' name="phone"/>
<input ref="email" className="email" type='tel' name="email"/>
<input type="submit" value="Submit"/>
</form>
</div>
);
}
}
export default UserInfo;
You could switch the onClick event handler on the button to an onSubmit handler on the form:
render : function() {
return (
<form onSubmit={this.handleLogin}>
<input type="text" name="email" placeholder="Email" />
<input type="password" name="password" placeholder="Password" />
<button type="submit">Login</button>
</form>
);
},
Then you can make use of FormData to parse the form (and construct a JSON object from its entries if you want).
handleLogin: function(e) {
const formData = new FormData(e.target)
const user = {}
e.preventDefault()
for (let entry of formData.entries()) {
user[entry[0]] = entry[1]
}
// Do what you will with the user object here
}
If all your inputs / textarea have a name, then you can filter all from event.target:
onSubmit(event){
const fields = Array.prototype.slice.call(event.target)
.filter(el => el.name)
.reduce((form, el) => ({
...form,
[el.name]: el.value,
}), {})
}
Totally uncontrolled form 😊 without onChange methods, value, defaultValue...
I would suggest the following approach:
import {Autobind} from 'es-decorators';
export class Form extends Component {
#Autobind
handleChange(e) {
this.setState({[e.target.name]: e.target.value});
}
#Autobind
add(e) {
e.preventDefault();
this.collection.add(this.state);
this.refs.form.reset();
}
shouldComponentUpdate() {
return false;
}
render() {
return (
<form onSubmit={this.add} ref="form">
<input type="text" name="desination" onChange={this.handleChange}/>
<input type="date" name="startDate" onChange={this.handleChange}/>
<input type="date" name="endDate" onChange={this.handleChange}/>
<textarea name="description" onChange={this.handleChange}/>
<button type="submit">Add</button>
</form>
)
}
}
Here is the shortest way to get data from the form and the best way to avoid id and ref just by using FormData:
import React, { Component } from 'react'
class FormComponent extends Component {
formSubmit = (event) => {
event.preventDefault()
var data = new FormData(event.target)
let formObject = Object.fromEntries(data.entries())
console.log(formObject)
}
render() {
return (
<div>
<form onSubmit={this.formSubmit}>
<label>Name</label>
<input name="name" placeholder="name" />
<label>Email</label>
<input type="email" name="email" />
<input type="submit" />
</form>
</div>
)
}
}
export default FormComponent
More clear example with es6 destructing
class Form extends Component {
constructor(props) {
super(props);
this.state = {
login: null,
password: null,
email: null
}
}
onChange(e) {
this.setState({
[e.target.name]: e.target.value
})
}
onSubmit(e) {
e.preventDefault();
let login = this.state.login;
let password = this.state.password;
// etc
}
render() {
return (
<form onSubmit={this.onSubmit.bind(this)}>
<input type="text" name="login" onChange={this.onChange.bind(this)} />
<input type="password" name="password" onChange={this.onChange.bind(this)} />
<input type="email" name="email" onChange={this.onChange.bind(this)} />
<button type="submit">Sign Up</button>
</form>
);
}
}
Give your inputs ref like this
<input type="text" name="email" placeholder="Email" ref="email" />
<input type="password" name="password" placeholder="Password" ref="password" />
Then you can access it in your handleLogin like so:
handleLogin: function(e) {
e.preventDefault();
console.log(this.refs.email.value)
console.log(this.refs.password.value)
}
I use like this using React Component state:
<input type="text" name='value' value={this.state.value} onChange={(e) => this.handleChange(e)} />
handleChange(e){
this.setState({[e.target.name]: e.target.value})
}`
Also, this can be used too.
handleChange: function(state,e) {
this.setState({[state]: e.target.value});
},
render : function() {
return (
<form>
<input type="text" name="email" placeholder="Email" value={this.state.email} onChange={this.handleChange.bind(this, 'email')} />
<input type="password" name="password" placeholder="Password" value={this.state.password} onChange={this.handleChange.bind(this, 'password')}/>
<button type="button" onClick={this.handleLogin}>Login</button>
</form>
);
},
handleLogin: function() {
console.log("EMail: ", this.state.email);
console.log("Password: ", this.state.password);
}
If you are using Redux in your project, you can consider using the higher order component redux-form.
In many events in JavaScript, we have event which gives an object, including what event happened and what are the values, etc.
That's what we use with forms in React as well.
So in your code you set the state to the new value. Something like this:
class UserInfo extends React.Component {
constructor(props) {
super(props);
this.handleLogin = this.handleLogin.bind(this);
}
handleLogin(e) {
e.preventDefault();
for (const field in this.refs) {
this.setState({this.refs[field]: this.refs[field].value});
}
}
render() {
return (
<div>
<form onSubmit={this.handleLogin}>
<input ref="email" type="text" name="email" placeholder="Email" />
<input ref="password" type="password" name="password" placeholder="Password" />
<button type="button">Login</button>
</form>
</div>
);
}
}
export default UserInfo;
Also this is the form example in React v.16, just as reference for the form you creating in the future:
class NameForm extends React.Component {
constructor(props) {
super(props);
this.state = {value: ''};
this.handleChange = this.handleChange.bind(this);
this.handleSubmit = this.handleSubmit.bind(this);
}
handleChange(event) {
this.setState({value: event.target.value});
}
handleSubmit(event) {
alert('A name was submitted: ' + this.state.value);
event.preventDefault();
}
render() {
return (
<form onSubmit={this.handleSubmit}>
<label>
Name:
<input type="text" value={this.state.value} onChange={this.handleChange} />
</label>
<input type="submit" value="Submit" />
</form>
);
}
}
onChange(event){
console.log(event.target.value);
}
handleSubmit(event){
event.preventDefault();
const formData = {};
for (const data in this.refs) {
formData[data] = this.refs[data].value;
}
console.log(formData);
}
<form onSubmit={this.handleSubmit.bind(this)}>
<input type="text" ref="username" onChange={this.onChange} className="form-control"/>
<input type="text" ref="password" onChange={this.onChange} className="form-control"/>
<button type="submit" className="btn-danger btn-sm">Search</button>
</form>
Output image attached here
To improve the user experience; when the user clicks on the submit button, you can try to get the form to first show a sending message. Once we've received a response from the server, it can update the message accordingly. We achieve this in React by chaining statuses. See codepen or snippets below:
The following method makes the first state change:
handleSubmit(e) {
e.preventDefault();
this.setState({ message: 'Sending...' }, this.sendFormData);
}
As soon as React shows the above Sending message on screen, it will call the method that will send the form data to the server: this.sendFormData(). For simplicity I've added a setTimeout to mimic this.
sendFormData() {
var formData = {
Title: this.refs.Title.value,
Author: this.refs.Author.value,
Genre: this.refs.Genre.value,
YearReleased: this.refs.YearReleased.value};
setTimeout(() => {
console.log(formData);
this.setState({ message: 'data sent!' });
}, 3000);
}
In React, the method this.setState() renders a component with new properties. So you can also add some logic in render() method of the form component that will behave differently depending on the type of response we get from the server. For instance:
render() {
if (this.state.responseType) {
var classString = 'alert alert-' + this.state.type;
var status = <div id="status" className={classString} ref="status">
{this.state.message}
</div>;
}
return ( ...
codepen
This might help Meteor (v1.3) users:
render: function() {
return (
<form onSubmit={this.submitForm.bind(this)}>
<input type="text" ref="email" placeholder="Email" />
<input type="password" ref="password" placeholder="Password" />
<button type="submit">Login</button>
</form>
);
},
submitForm: function(e) {
e.preventDefault();
console.log( this.refs.email.value );
console.log( this.refs.password.value );
}
This is an example of dynamically added fields. Here form data will store by input name key using a React useState hook.
import React, { useState } from 'react'
function AuthForm({ firebase }) {
const [formData, setFormData] = useState({});
// On Form Submit
const onFormSubmit = (event) => {
event.preventDefault();
console.log('data', formData)
// Submit here
};
// get Data
const getData = (key) => {
return formData.hasOwnProperty(key) ? formData[key] : '';
};
// Set data
const setData = (key, value) => {
return setFormData({ ...formData, [key]: value });
};
console.log('firebase', firebase)
return (
<div className="wpcwv-authPage">
<form onSubmit={onFormSubmit} className="wpcwv-authForm">
<input name="name" type="text" className="wpcwv-input" placeholder="Your Name" value={getData('name')} onChange={(e) => setData('name', e.target.value)} />
<input name="email" type="email" className="wpcwv-input" placeholder="Your Email" value={getData('email')} onChange={(e) => setData('email', e.target.value)} />
<button type="submit" className="wpcwv-button wpcwv-buttonPrimary">Submit</button>
</form>
</div>
)
}
export default AuthForm
For TypeScript users
import react from 'react'
interface FormInterface {
[key: string]: string
}
const handleSubmit = (event: React.FormEvent<HTMLFormElement>) => {
event.preventDefault();
let formData = new FormData(event.currentTarget)
let formObj: FormInterface = {}
for (let [key, value] of Array.from(formData.entries())) {
formObj[key] = value.toString()
}
};
<form onSubmit={handleSubmit}>
<input type="text" name="email" placeholder="Email" />
<input type="password" name="password" placeholder="Password" />
<button type="submit">Login</button>
</form>
The simplest solution that came to my mind is this:
<form onSubmit={(e) => handleLogin(e)}>
<input type="text" name="email" placeholder="Email" />
<input type="password" name="password" placeholder="Password" />
<button type="submit">Login</button>
</form>
Your handle fuction:
const handleLogin = (e) => {
e.preventDefault()
const data = {
email: e.target.elements.email.value,
password: e.target.elements.password.value
}
console.log('FormData: ', data)
}
When you click on your login button you will see FormData in console in this format:
FormData: {email: 'whatever you tiped here', password: 'also whatever you tiped here'}.
e.target.elements.email.value targets elements with specific name, in your case it is email and password.
After console.log in handleLogin, you can do some verification logic and login logic.
If you have multiple occurrences of an element name, then you have to use forEach().
HTML
<input type="checkbox" name="delete" id="flizzit" />
<input type="checkbox" name="delete" id="floo" />
<input type="checkbox" name="delete" id="flum" />
<input type="submit" value="Save" onClick={evt => saveAction(evt)}></input>
JavaScript
const submitAction = (evt) => {
evt.preventDefault();
const dels = evt.target.parentElement.delete;
const deleted = [];
dels.forEach((d) => { if (d.checked) deleted.push(d.id); });
window.alert(deleted.length);
};
Note the dels in this case is a RadioNodeList, not an array, and is not an Iterable. The forEach() is a built-in method of the list class. You will not be able to use a map() or reduce() here.
TypeScript will complain if you try Aliaksandr Sushkevich's solution. One workaround can be done using type assertions:
<form
onSubmit={(e: React.SyntheticEvent) => {
e.preventDefault();
const target = e.target as typeof e.target & {
username: { value: string };
password: { value: string };
};
const username = target.username.value; // typechecks
const password = target.password.value; // typechecks
// etc...
}}
>
<input type="text" name="username"/>
...
Though, this is still just a workaround, because here you are telling TypeScript what to expect. This will break at runtime if you add a value that doesn't have a corresponding input element.
I think this is also the answer that you need. In addition, Here I add the required attributes. onChange attributes of Each input components are functions. You need to add your own logic there.
handleEmailChange: function(e) {
this.setState({email: e.target.value});
},
handlePasswordChange: function(e) {
this.setState({password: e.target.value});
},
formSubmit : async function(e) {
e.preventDefault();
// Form submit Logic
},
render : function() {
return (
<form onSubmit={(e) => this.formSubmit(e)}>
<input type="text" name="email" placeholder="Email" value={this.state.email} onChange={this.handleEmailChange} required />
<input type="password" name="password" placeholder="Password" value={this.state.password} onChange={this.handlePasswordChange} required />
<button type="button">Login</button>
</form>);
},
handleLogin: function() {
//Login Function
}
Here is my approach for collecting multiple form inputs using single inputChangeHandler
import React from "react";
const COLORS = ["red", "orange", "yellow", "purple", "green", "white", "black"];
export default function App() {
const initialFormFields = {
name: undefined,
email: undefined,
favourite_color: undefined
};
const [formInput, setFormInput] = React.useState(initialFormFields);
function inputChangeHandler(event) {
setFormInput(prevFormState => ({
...prevFormState,
[event.target.name]: event.target.value
}))
};
return (
<div className="App">
<form>
<label>Name: <input name="name" type="text" value={formInput.name} onChange={inputChangeHandler}/></label>
<label>Email: <input name="email" type="email" value={formInput.email} onChange={inputChangeHandler}/></label>
<div>
{COLORS.map(color => <label><input type="radio" name="favourite_color" value={color} key={color} onChange={inputChangeHandler}/> {color} </label>)}
</div>
</form>
<div>
Entered Name: {formInput.name}
Entered Email: {formInput.email}
Favourite Color: {formInput.favourite_color}
</div>
</div>
);
}
This will be the easiest method:
const formValidator = (form) => {
let returnData = {}
console.log(form.length);
for (let i = 0; i < form.length; i++) {
const data = form[i]
if (data.name != null && data.name != "") {
returnData[data.name] = data.value;
}
}
return returnData
}
In the form, simply use:
<form onSubmit={(e) => {
e.preventDefault()
let data = formValidator(e.currentTarget)
}}>
<RoundTextFiled name='app-id' style={{ marginTop: '10px', borderRadius: '20px' }} label="App id" fullWidth required />
<RoundTextFiled name='api-hash' style={{ marginTop: '5px' }} label="Api hash" fullWidth required />
<RoundTextFiled name='channel-id' style={{ marginTop: '5px' }} label="Channel id" fullWidth required />
<Button type='submit' variant="contained" fullWidth style={{ padding: '10px', marginTop: '5px', borderRadius: '10px' }}>Login</Button>
</form>
<form onSubmit={handleLogin}>
<input type="text" name="email" placeholder="Email" />
<input type="text" name="password" placeholder="Password" />
<button type="submit">Login</button>
</form>
const handleLogin = (event) => {
event.preventDefault();
console.log(event.target[0].value)
console.log(event.target[1].value)
}
Use:
import { useState } from 'react'
export default function App() {
const [data, setData] = useState({})
const updateData = e => {
setData({
...data,
[e.target.name]: e.target.value
})
}
const submit = e => {
e.preventDefault()
console.log(data)
}
return (
<form onSubmit={submit}>
<input
name="email"
type="email"
onChange={updateData}
/>
<input
name="password"
type="password"
onChange={updateData}
/>
<button>Submit</button>
</form>
)
}

Resources