React input mask TS

npm install react-input-mask-ts

yarn add react-input-mask-ts

pnpm add react-input-mask-ts

Usage

import React from 'react'
import InputMask from 'react-input-mask-ts'

function DateInput(props) {
  return (
    <InputMask
      mask="99/99/9999"
      onChange={props.onChange}
      value={props.value}
    />
  );
}

Properties

mask

Mask format. Can be either a string or array of characters and regular expressions.

<InputMask mask="99/99/99" />

Simple masks can be defined as strings. The following characters will define mask format:

Any format character can be escaped with a backslash.

More complex masks can be defined as an array of regular expressions and constant characters.

// Canadian postal code mask
const firstLetter = /(?!.*[DFIOQU])[A-VXY]/i;
const letter = /(?!.*[DFIOQU])[A-Z]/i;
const digit = /[0-9]/;
const mask = [firstLetter, digit, letter, " ", digit, letter, digit];
return <InputMask mask={mask} />;

maskPlaceholder

// Will be rendered as 12/--/--
<InputMask mask="99/99/99" maskPlaceholder="-" value="12" />

// Will be rendered as 12/mm/yy
<InputMask mask="99/99/99" maskPlaceholder="dd/mm/yy" value="12" />

// Will be rendered as 12/
<InputMask mask="99/99/99" maskPlaceholder={null} value="12" />

Character or string to cover unfilled parts of the mask. Default character is "_". If set to null or empty string, unfilled parts will be empty as in a regular input.

alwaysShowMask

If enabled, mask prefix and placeholder will be displayed even when input is empty and has no focus.

beforeMaskedStateChange

In case you need to customize masking behavior, you can provide beforeMaskedStateChange function to change masked value and cursor position before it's applied to the input.

It receieves an object with previousState, currentState and nextState properties. Each state is an object with value and selection properites where value is a string and selection is an object containing start and end positions of the selection.

1. previousState: Input state before change. Only defined on change event.
2. currentState: Current raw input state. Not defined during component render.
3. nextState: Input state with applied mask. Contains value and selection fields.

Selection positions will be null if input isn't focused and during rendering.

beforeMaskedStateChange must return a new state with value and selection.

// Trim trailing slashes
function beforeMaskedStateChange({ nextState }) {
  let { value } = nextState;
  if (value.endsWith('/')) {
    value = value.slice(0, -1);
  }

  return {
    ...nextState,
    value
  };
}

return (
  <InputMask
    mask="99/99/99"
    maskPlaceholder={null}
    beforeMaskedStateChange={beforeMaskedStateChange}
  />
);

Please note that beforeMaskedStateChange executes more often than onChange and must be pure.

children

To use another component instead of regular <input /> provide it as children. The following properties, if used, should always be defined on the InputMask component itself: onChange, onMouseDown, onFocus, onBlur, value, disabled, readOnly.

import React from 'react';
import InputMask from 'react-input-mask-ts';
import MaterialInput from '@material-ui/core/Input';

// Will work fine
function Input(props) {
  return (
    <InputMask mask="99/99/9999" value={props.value} onChange={props.onChange}>
      <MaterialInput type="tel" disableUnderline />
    </InputMask>
  );
}

// Will throw an error because InputMask's and children's onChange props aren't the same
function InvalidInput(props) {
  return (
    <InputMask mask="99/99/9999" value={props.value}>
      <MaterialInput type="tel" disableUnderline onChange={props.onChange} />
    </InputMask>
  );
}