Página de login do Spring Security com React

import React, { Component } from 'react'
import PropTypes from 'prop-types'

class Input extends Component {
    constructor(props){
        super(props)
        this.state = {
            value: props.value? props.value : '',
            className: props.className? props.className : '',
            error: false
        }
    }

    //...

    render () {
        const {handleError, ...opts} = this.props
        this.handleError = handleError
        return (
          
        )
    }
}

Input.propTypes = {
  name: PropTypes.string,
  placeholder: PropTypes.string,
  type: PropTypes.string,
  className: PropTypes.string,
  value: PropTypes.string,
  handleError: PropTypes.func
}

export default Input

import React, { Component } from 'react'
import PropTypes from 'prop-types'
import Input from './Input'

class Form extends Component {

    //...

    render() {
        const inputs = this.props.inputs.map(
          ({name, placeholder, type, value, className}, index) => (
            
          )
        )
        const errors = this.renderError()
        return (
            
 {this.form=fm}} >
              {inputs}
              {errors}
            
        )
    }
}

Form.propTypes = {
  name: PropTypes.string,
  action: PropTypes.string,
  method: PropTypes.string,
  inputs: PropTypes.array,
  error: PropTypes.string
}

export default Form

class Form extends Component {

    constructor(props) {
        super(props)
        if(props.error) {
            this.state = {
              failure: 'wrong username or password!',
              errcount: 0
            }
        } else {
            this.state = { errcount: 0 }
        }
    }

    handleError = (field, errmsg) => {
        if(!field) return

        if(errmsg) {
            this.setState((prevState) => ({
                failure: '',
                errcount: prevState.errcount + 1,
                errmsgs: {...prevState.errmsgs, [field]: errmsg}
            }))
        } else {
            this.setState((prevState) => ({
                failure: '',
                errcount: prevState.errcount===1? 0 : prevState.errcount-1,
                errmsgs: {...prevState.errmsgs, [field]: ''}
            }))
        }
    }

    renderError = () => {
        if(this.state.errcount || this.state.failure) {
            const errmsg = this.state.failure
              || Object.values(this.state.errmsgs).find(v=>v)
            return 
{errmsg}
        }
    }

    //...

}

class Form extends Component {

    //...

    handleSubmit = (event) => {
        event.preventDefault()
        if(!this.state.errcount) {
            const data = new FormData(this.form)
            fetch(this.form.action, {
              method: this.form.method,
              body: new URLSearchParams(data)
            })
            .then(v => {
                if(v.redirected) window.location = v.url
            })
            .catch(e => console.warn(e))
        }
    }
}

import React from 'react'
import ReactDOM from 'react-dom'
import './index.css'
import Form from './Form'

const inputs = [{
  name: "username",
  placeholder: "username",
  type: "text"
},{
  name: "password",
  placeholder: "password",
  type: "password"
},{
  type: "submit",
  value: "Submit",
  className: "btn"
}]

const props = {
  name: 'loginForm',
  method: 'POST',
  action: '/perform_login',
  inputs: inputs
}

const params = new URLSearchParams(window.location.search)

ReactDOM.render(
  
,
  document.getElementById('container'))