react-number-format

What is react-number-format?

The react-number-format package is a React component designed for formatting number input fields. It allows users to format numbers as currency, percentages, decimals, phone numbers, credit card numbers, and other custom formats. It also supports features like custom prefix, suffix, and thousand separator, masking, and custom formatting.

What are react-number-format's main functionalities?

Number Formatting

This feature allows you to format numbers with thousands separators and add a prefix. In this example, the number 2456981 is formatted as currency with a dollar sign prefix and commas as thousand separators, displayed as $2,456,981.

import NumberFormat from 'react-number-format';

<NumberFormat value={2456981} displayType={'text'} thousandSeparator={true} prefix={'$'} />

Custom Format

This feature enables custom formatting for inputs. Here, the format prop defines the pattern for a phone number and the mask prop is used for placeholder characters, allowing users to enter a phone number in the format ###-###-####.

import NumberFormat from 'react-number-format';

<NumberFormat format="###-###-####" mask="_" />

Currency Formatting

This feature is used to format input as currency. It includes a thousand separator, a dollar sign prefix, and ensures that there are always two decimal places.

import NumberFormat from 'react-number-format';

<NumberFormat thousandSeparator={true} prefix={'$'} decimalScale={2} fixedDecimalScale={true} />

Other packages similar to react-number-format

cleave.js

Cleave.js is a library that can format input text content when you are typing. It provides similar functionalities to react-number-format, such as number formatting, credit card formatting, phone number formatting, and date formatting. It differs in that it is not React-specific and can be used with plain JavaScript or other frameworks.

numeral

Numeral is a library for formatting and manipulating numbers. It's similar to react-number-format in that it can format numbers as currency, percentages, and other formats. However, it is not a React component and does not handle input fields directly. It is more focused on number manipulation and formatting in general JavaScript applications.

currency.js

Currency.js is a small and lightweight library for working with currency values. It allows you to perform arithmetic operations and formatting on currency numbers. While it provides similar currency formatting capabilities, it does not come as a React component and is more suited for general arithmetic and formatting operations rather than handling user input.

README

react-number-format

React component to format number in an input or as a text

Features

1. Prefix, suffix and thousand separator.
2. Custom format pattern.
3. Masking.
4. Custom formatting handler.
5. Format number in an input or format as a simple text.

Install

Through npm npm install react-number-format --save

Or get compiled development and production version from ./dist

Usage

ES6

import NumberFormat from 'react-number-format';

ES5

const NumberFormat = require('react-number-format');

Typescript

import NumberFormat from 'react-number-format';
//or
import { default as NumberFormat } from 'react-number-format';

In typescript you also have to enable "esModuleInterop": true in your tsconfig.json (https://www.typescriptlang.org/docs/handbook/compiler-options.html).

Props

Props	Options	Default	Description
thousandSeparator	mixed: single character string or boolean true (true is default to ,)	none	Add thousand separators on number.
decimalSeparator	single character string	.	Support decimal point on a number.
thousandsGroupStyle	One of ['thousand', 'lakh', 'wan']	thousand	Define the thousand grouping style, It support three types. thousand style (thousand) : 123,456,789, indian style (lakh) : 12,34,56,789, chinese style (wan) : 1,2345,6789.
decimalScale	number	none	If defined it limits to given decimal scale.
fixedDecimalScale	boolean	false	If true it add 0s to match given decimalScale.
allowNegative	boolean	true	allow negative numbers (Only when format option is not provided).
allowEmptyFormatting	boolean	false	Apply formatting to empty inputs.
allowLeadingZeros	boolean	false	Allow leading zeros at beginning of number.
prefix	String (ex : $)	none	Add a prefix before the number.
suffix	String (ex : /-)	none	Add a suffix after the number.
value	Number or String	null	Value to the number format. It can be a float number, or formatted string. If value is string representation of number (unformatted), isNumericString props should be passed as true.
defaultValue	Number or String	null	Value to be used as default value if value is not provided. The format of defaultValue should be similar as defined for the value.
isNumericString	boolean	false	If value is passed as string representation of numbers (unformatted) then this should be passed as true.
displayType	String: text / input	input	If input it renders a input element where formatting happens as you input characters. If text it renders it as a normal text in a span formatting the given value.
type	One of ['text', 'tel', 'password']	text	Input type attribute.
format	String : Hash based ex (#### #### #### ####) Or Function	none	If format given as hash string allow number input inplace of hash. If format given as function, component calls the function with unformatted number and expects formatted number.
removeFormatting	(formattedValue) => numericString	none	If you are providing custom format method and it add numbers as format you will need to add custom removeFormatting logic.
mask	String (ex : _)	' '	If mask defined, component will show non entered placed with masked value.
customInput	Component Reference	input	This allow supporting custom inputs with number format.
onValueChange	(values, sourceInfo) => {}	none	onValueChange handler accepts values object.
isAllowed	(values) => true or false	none	A checker function to check if input value is valid or not. If this function returns false, the onChange method will not get triggered.
renderText	(formattedValue, customProps) => React Element	null	A renderText method useful if you want to render formattedValue in different element other than span. It also returns the custom props that are added to the component which can allow passing down props to the rendered element.
getInputRef	(elm) => void	null	Method to get reference of input, span (based on displayType prop) or the customInput's reference. See Getting reference.
allowedDecimalSeparators	array of char	none	Characters which when pressed result in a decimal separator. When missing, decimal separator and '.' are used.
customNumerals	array of string	none	an array of 10 single-character strings with represent numerals in different locales. ranging from 0 - 9. the result will be converted to english numeral and treated as number

Other than this it accepts all the props which can be given to a input or span based on displayType you selected.

values object

values object is on following format

{
  formattedValue: '$23,234,235.56', //value after applying formatting
  value: '23234235.56', //non formatted value as numeric string 23234235.56, if you are setting this value to state make sure to pass isNumericString prop to true
  floatValue: 23234235.56 //floating point representation. For big numbers it can have exponential syntax
}

Its recommended to use formattedValue / value / floatValue based on the initial state (it should be same as the initial state format) which you are passing as value prop. If you are saving the value key on state make sure to pass isNumericString prop to true.

Notes and quirks

1. Value can be passed as string or number, but if it is passed as string it should be either formatted value or if it is a numeric string, you have to set isNumericString props to true.

2. Value as prop will be rounded to given decimal scale if format option is not provided.

3. If you want to block floating number set decimalScale to 0.

4. Use type as tel when you are providing format prop. This will change the mobile keyboard layout to have only numbers. In other case use type as text, so user can type decimal separator.

5. onChange no longer gets values object. You need to use onValueChange instead. onChange/onFocus/onBlur and other input events will be directly passed to the input.

6. Its recommended to use formattedValue / value / floatValue based on the initial state (it should be same as the initial state format) which you are passing as value prop. If you are saving the value key on state make sure to pass isNumericString prop to true.

7. onValueChange is not same as onChange. It gets called on whenever there is change in value which can be caused by any event like change or blur event or by a prop change. It also provides a second argument which contains the event object and the reason for this function trigger.

Examples

Prefix and thousand separator : Format currency as text.

var NumberFormat = require('react-number-format');

<NumberFormat value={2456981} displayType={'text'} thousandSeparator={true} prefix={'$'} />;

Output : $2,456,981

Custom renderText method.

var NumberFormat = require('react-number-format');

<NumberFormat
  value={2456981}
  className="foo"
  displayType={'text'}
  thousandSeparator={true}
  prefix={'$'}
  renderText={(value, props) => <div {...props}>{value}</div>}
/>;

Output : <div class="foo"> $2,456,981 </div>

Format with pattern : Format credit card as text.

<NumberFormat value={4111111111111111} displayType={'text'} format="#### #### #### ####" />

Output : 4111 1111 1111 1111

Prefix and thousand separator : Format currency in input.

<NumberFormat thousandSeparator={true} prefix={'$'} />

Indian(lakh) style and chinese(wan) style number grouping.

Indian (lakh) style grouping

<NumberFormat thousandSeparator={true} thousandsGroupStyle="lakh" prefix={'₹'} value={123456789} />

Output: ₹12,34,56,789

Chinese (wan) style grouping.

<NumberFormat thousandSeparator={true} thousandsGroupStyle="wan" prefix={'¥'} value={123456789} />

Output: ¥1,2345,6789

Maintaining change value on state

<NumberFormat
  value={this.state.profit}
  thousandSeparator={true}
  prefix={'$'}
  onValueChange={(values) => {
    const { formattedValue, value } = values;
    // formattedValue = $2,223
    // value ie, 2223
    this.setState({ profit: formattedValue });
  }}
/>

Accessing event and the source for onValueChangeTrigger

<NumberFormat
  value={this.state.profit}
  thousandSeparator={true}
  prefix={'$'}
  onValueChange={(values, sourceInfo) => {
    const { formattedValue, value } = values;
    // Event is a Synthetic Event wrapper which holds target and other information. Source tells whether the reason for this function being triggered was an 'event' or due to a 'prop' change
    const { event, source } = sourceInfo;
  }}
/>

Format with pattern : Format credit card in an input.

<NumberFormat format="#### #### #### ####" />

Format with mask : Format credit card in an input

<NumberFormat format="#### #### #### ####" mask="_" />

Format with mask as array

Mask can also be a array of string. Each item corresponds to the same index #.

<NumberFormat format="##/##" placeholder="MM/YY" mask={['M', 'M', 'Y', 'Y']} />

Custom format method : Format credit card expiry time

function limit(val, max) {
  if (val.length === 1 && val[0] > max[0]) {
    val = '0' + val;
  }

  if (val.length === 2) {
    if (Number(val) === 0) {
      val = '01';

      //this can happen when user paste number
    } else if (val > max) {
      val = max;
    }
  }

  return val;
}

function cardExpiry(val) {
  let month = limit(val.substring(0, 2), '12');
  let year = val.substring(2, 4);

  return month + (year.length ? '/' + year : '');
}

<NumberFormat format={cardExpiry} />;

Format phone number

<NumberFormat format="+1 (###) ###-####" mask="_" />

Custom Numeral

  const persianNumeral = ['۰', '۱', '۲', '۳', '۴', '۵', '۶', '۷', '۸', '۹']
  <NumberFormat customNumerals={persianNumeral} />;

Limit input value to a maximum limit

const MAX_VAL = 1400;
const withValueLimit = ({ floatValue }) => floatValue <= MAX_VAL;
<NumberFormat value={12} isAllowed={withValueLimit} />;

It is sensible to use floatValue in the withValueLimit check because it provides the exact value (see values object). value is rounded to your configured decimalScale; hence it may omit a part of the precision of the actual value. Given an entered value of 1400.4 and the default decimalScale, value would be transferred as 1400 in the values object and pass the above withValueLimit check. In this case, it is a false positive that can be prevented using floatValue. However, you might want to use value to automatically get the rounded number according to your decimalScale.

Visit this link for Demo: Field with value limit

Show mask on empty input

<NumberFormat format="+1 (###) ###-####" allowEmptyFormatting mask="_" />

Custom Inputs

You can easily extend your custom input with number format. But custom input should have all input props.

import TextField from 'material-ui/TextField';

<NumberFormat customInput={TextField} format="#### #### #### ####" />

Passing custom input props All custom input props and number input props are passed together.

<NumberFormat
  hintText="Some placeholder"
  value={this.state.card}
  customInput={TextField}
  format="#### #### #### ####"
/>

Getting reference

As ref is a special property in react, its not passed as props. If you add ref property it will give you the reference of NumberFormat instance. In case you need input reference. You can use getInputRef prop instead.

<NumberFormat
  getInputRef={(el) => (this.inputElem = el)}
  customInput={TextField}
  format="#### #### #### ####"
/>

Or using React.createRef()

const inputRef = React.createRef();
<NumberFormat getInputRef={inputRef} customInput={TextField} format="#### #### #### ####" />;

In case you have provided custom input you can pass there props to get the input reference (getInputRef will not work in that case). For ex in material-ui component.

<NumberFormat
  inputRef={(el) => (this.inputElem = el)}
  customInput={TextField}
  format="#### #### #### ####"
/>

If you can't get in both way you can try ReactDOM.findDOMNode. You may need to traverse if input is not the top level element.

<NumberFormat
  ref={(inst) => (this.inputElem = ReactDOM.findDOMNode(inst))}
  format="#### #### #### ####"
/>

Live Demo

http://codepen.io/s-yadav/pen/bpKNMa

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Migrate v2 to v3

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Updates

For regular updates follow me on _syadav

Major updates

v4.0.0

Breaking Changes

• onValueChange no longer receives event object as second parameter, so if you accessing it, it will break.

Feature Addition

• Support defaultValue prop.
• Trigger onValueChange if the value is formatted due to prop change.
• Allow password as type prop.
• Support indian (lakh) and chinese (wan) style thousand grouping.
• Always allow . to be typed as decimal separator, even when decimal separator is defined differently

v3.0.0

• onChange no longer gets values object. You need to use onValueChange instead. This is done because formatted value may change on onBlur event. calling onChange on onBlur doesn't feel right.
• decimalPrecision is changed to decimalScale. Precision is the number of digits in a number. Scale is the number of digits to the right of the decimal point in a number.
• decimalScale by default will not add 0s to match provided decimalScale value like decimalPrecision. You have to set fixedDecimalScale to true.
• mask can be now array of string in which case mask at specific index will be mapped with the # of the pattern.
• Value can be passed as string or number, but if it is passed as string it should be either formatted value or if it is a numeric string, you have to set isNumericString props to true.
• Added support for numbers in prefix / suffix / pattern.
• Fixed caret position and formatting issues.
• Lot of bugs and stability fixes (See release notes)

v2.0.0

• Added isAllowed prop to validate custom input and reject input based on it.
• onChange api been changed. Now it receives values object as second parameter.
• decimalSeparator no longer support boolean values
• thousandSeparator accepts only true as boolean (which defaults to ,) or thousandSeparator string
• decimalPrecision only accepts number now
• Value can be passed as string or number but if it is passed as string you should maintain the same decimal separator on the string what you provided as decimalSeparator prop.
• Added back the type prop for the input type attribute (Only text or tel is supported)
• Enforce cursor to be between prefix and suffix in focus, click or arrow navigation.
• Lot of bugs and stability fixes (See release notes)

Development

• Clone the repository or download the zip
• npm i -g yarn to download Yarn
• yarn to install dependencies
• yarn start to run example server (http://localhost:8084/)
• yarn test to test changes
• yarn bundle to bundle files

Testing

Test cases are written in jasmine and run by karma Test file : /test/test_input.js To run test : yarn test