OTP component

InputOTP.js

import React from 'react'
import './styles.scss'
import { elem } from '_helpers/css'

/**
 * @param {length} number -  Default value is 4
 * @param {error} string -  Default value is none
 * @param {placeholder} string -  Default value is none
 * @param {onChange} function -  Default value is none
 */

class InputOTP extends React.Component {
  state = {
    value: ['', '', '', '', '', '', '', '', ''],
    currentKey: false
  }

  componentDidMount() {
    elem(`otp${0}`) && elem(`otp${0}`).focus() // when component shows up, first input is focussed
  }

  onChange = ({ index, event }) => {
    const key = event.key
    const targetValue = event.target.value
    if (targetValue === '') {
      this.changeValue(targetValue, index)
    } else if (targetValue < 10 && targetValue !== ' ' && !isNaN(targetValue)) {
      this.changeValue(targetValue, index)
    }
  }

  changeValue = (value, index) => {
    let newArr = this.state.value
    newArr[index] = value
    this.setState({ value: newArr }, () => this.changeIndex(index, newArr))
  }

  changeIndex = (index, newArr) => {
    const currentElement = elem(`otp${index}`)
    const nextElement = elem(`otp${index + 1}`)
    const prvElement = elem(`otp${index - 1}`)
    if (currentElement.value === '') {
    } else if (
      currentElement.value &&
      nextElement &&
      nextElement.value === ''
    ) {
      nextElement.focus()
    }
    this.blur(newArr.join(''))
  }

  blur = (value) => {
    this.props.onChange(value)
  }

  onKeyDown = ({ index, event }) => {
    const currentElement = elem(`otp${index}`)
    const nextElement = elem(`otp${index + 1}`)
    const prvElement = elem(`otp${index - 1}`)
    const key = event.key
    switch (key) {
      case 'Backspace':
        if (prvElement && currentElement.value === '') {
          prvElement && prvElement.focus()
        } else {
        }
        break
      case 'ArrowRight':
        this.timeout(nextElement)
        this.setState({ currentKey: false })
        break
      case 'ArrowLeft':
        this.timeout(prvElement)
        this.setState({ currentKey: false })
        break
      case ' ':
        break
      case 'ArrowUp':
      case 'ArrowDown':
        event.preventDefault()
        break
      default:
        break
    }
  }

  timeout = (element) => {
    element &&
      setTimeout(() => {
        const x = element.value
        element.value = ''
        element.value = x
        element.focus()
      }, 1)
  }

  render() {
    const { length = 4, error, placeholder } = this.props
    let input = []
    for (let i = 0; i < length; i++) {
      input.push(
        <input
          type="number"
          id={`otp${i}`}
          key={`otp${i}`}
          className={`input ${error ? 'errorBorder' : ''}`}
          maxLength={1}
          onChange={(event) => this.onChange({ index: i, event })}
          value={this.state.value[i]}
          // onKeyUp={event => this.onKeyUp({ index: i, event })}
          onKeyDown={(event) => this.onKeyDown({ index: i, event })}
          placeholder={placeholder || ''}
          // placeholder={placeholder || '⬤'}
          autoComplete={'off'}
        />
      )
    }

    return (
      <div className="InputOTP">
        <div className="inputs">{input}</div>
        {error && <div className="error">{error}</div>}
      </div>
    )
  }
}

export default InputOTP

styles.scss

// @import "~scss/base/globals";

.InputOTP {
  width: 100%;

  .error {
    padding-left: 2px;
    font-size: 9px;
    color: #cc001a;
  }

  .input {
    width: 20px;
    outline: 0;
    border: 0;
    border: 1px solid gray;
    padding: 8px 0px 10px 0px;
    width: 38px;
    background-position: bottom;
    background-size: 50px 1px;
    background-repeat: repeat-x;
    background-position-x: 35px;
    margin: 5px;
    display: inline-block;
    // padding: 0 0 10px 0;
    text-align: center;
  }

  .input:focus {
    outline: none;
    border: 0;
    background-image: null;
    border: 1px solid black;
  }

  .input::-webkit-input-placeholder {
    /* Edge */
    color: rgba(0, 0, 0, 0.137);
    font-size: 10px;
  }

  .input:-ms-input-placeholder {
    /* Internet Explorer 10-11 */
    color: rgba(0, 0, 0, 0.137);
    font-size: 10px;
  }

  .input::placeholder {
    color: rgba(0, 0, 0, 0.137);
    font-size: 10px;
    line-height: normal;
  }
  input[type='number']::-webkit-outer-spin-button,
  input[type='number']::-webkit-inner-spin-button {
    -webkit-appearance: none;
    margin: 0;
  }

  input[type='number'] {
    -moz-appearance: textfield;
  }
}