React Native Currency Input

A simple currency input component for both iOS and Android.

The goal of react-native-currency-input is to offer a simple and effective way to handle number inputs with custom format, usually a currency input, but it can be used for any number input case.

• Features
• Installation
• Basic Usage
• Advanced Usage
• Using custom TextInput
• Props
• Example
• FakeCurrencyInput
  • FakeCurrencyInput Usage
  • FakeCurrencyInput Props
• formatNumber
  • formatNumber Options

Features

• A simple and practical component for number inputs
• It's just a <TextInput/> component, so you can use its props and it's easy to customize
• Handle any number format with these powerful props: precision, delimiter, separator, prefix and suffix.
• It handles negative values and you can choose the position of the sign with the signPosition.
• Set minimun and maximum values with minValue and maxValue.
• Use React Native ES6 and React Hooks

BONUS

• <FakeCurrencyInput />: A fake input that hides the real TextInput in order to get rid of the flickering issue
• formatNumber(): A function that formats number

Installation

npm install react-native-currency-input

or

yarn add react-native-currency-input

Basic Usage

import CurrencyInput from 'react-native-currency-input';

function MyComponent() {
  const [value, setValue] = React.useState(2310.458); // can also be null

  return <CurrencyInput value={value} onChangeValue={setValue} />;
}

Advanced Usage

import CurrencyInput from 'react-native-currency-input';

function MyComponent() {
  const [value, setValue] = React.useState(2310.458);

  return (
    <CurrencyInput
      value={value}
      onChangeValue={setValue}
      prefix="R$"
      delimiter="."
      separator=","
      precision={2}
      minValue={0}
      showPositiveSign
      onChangeText={(formattedValue) => {
        console.log(formattedValue); // R$ +2.310,46
      }}
    />
  );
}

Using custom TextInput

import CurrencyInput from 'react-native-currency-input';
import { Input } from 'native-base';

function MyComponent() {
  const [value, setValue] = React.useState(2310.458);

  return (
    <CurrencyInput
      value={value}
      onChangeValue={setValue}
      renderTextInput={textInputProps => <Input {...textInputProps} variant='filled' />}
      renderText
      prefix="R$"
      delimiter="."
      separator=","
      precision={2}
    />
  );
}

Props

Prop	Type	Default	Description
...TextInputProps			Inherit all props of TextInput.
value	number		The value for controlled input. REQUIRED
onChangeValue	function		Callback that is called when the input's value changes. REQUIRED
prefix	string		Character to be prefixed on the value.
suffix*	string		Character to be suffixed on the value.
delimiter	string	,	Character for thousands delimiter.
separator	string	.	Decimal separator character.
precision	number	2	Decimal precision.
maxValue	number		Max value allowed. Might cause unexpected behavior if you pass a value higher than the one defined here.
minValue	number		Min value allowed. Might cause unexpected behavior if you pass a value lower than the one defined here.
signPosition	string	"afterPrefix"	Where the negative/positive sign (+/-) should be placed.
showPositiveSign	boolean	false	Set this to true to show the + character on positive values.
onChangeText	function		Callback that is called when the input's text changes. IMPORTANT: This does not control the input value, you must use onChangeValue.
renderTextInput	function		Use a custom TextInput component.

* IMPORTANT: Be aware that using the suffix implies setting the selection property of the TextInput internally. You can override the selection, but that will cause behavior problems on the component

Tip: If you don't want negative values, just use minValue={0}.

Example

See EXAMPLE

git clone https://github.com/caioquirinomedeiros/react-native-currency-input.git
cd react-native-currency-input/example
yarn
yarn android / yarn ios

FakeCurrencyInput

This component hides the TextInput and use a Text on its place, so you'll lost the cursor, but will get rid of the flickering issue. To replace the cursor it's used a pipe character (|) that will be always at the end of the text. It also have a wrapper View with position "relative" on which the TextInput is stretched over.

• Pros
  • No flickering issue as a controlled input component
  • The cursor is locked at the end, avoiding the user to mess up with the mask
• Cons
  • Lost of selection functionality. The user will still be able to copy/paste, but with a bad experience
  • The cursor is locked at the end...

FakeCurrencyInput Usage

import { FakeCurrencyInput } from 'react-native-currency-input';

function MyComponent() {
  const [value, setValue] = React.useState(0); // can also be null

  return (
    <FakeCurrencyInput
      value={value}
      onChangeValue={setValue}
      prefix="$"
      delimiter=","
      separator="."
      precision={2}
      onChangeText={(formattedValue) => {
        // ...
      }}
    />
  );
}

FakeCurrencyInput Props

It includes the same props of the CurrencyInput with the additional of the following:

Prop	Type	Default	Description
...CurrencuInputProps			Inherit all props of CurrencyInput.
containerStyle	style prop		Style for the container View that wraps the Text.
caretColor	string	#6495ed	Color of the caret. Same as caretStyle.color.
caretStyle	style prop		Style for the caret text component.

formatNumber(value, options)

import { formatNumber } from 'react-native-currency-input';

const value = -2375923.3;

const formattedValue = formatNumber(value, {
  separator: ',',
  prefix: 'R$ ',
  precision: 2,
  delimiter: '.',
  signPosition: 'beforePrefix',
});

console.log(formattedValue); // -R$ 2.375.923,30

options (optional)

Name	Type	Default	Description
prefix	string		Character to be prefixed on the value.
suffix	string		Character to be suffixed on the value.
delimiter	string	,	Character for thousands delimiter.
separator	string	.	Decimal separator character.
precision	number	2	Decimal precision.
ignoreNegative	boolean	false	Set this to true to disable negative values.
signPosition	string	"afterPrefix"	Where the negative/positive sign (+/-) should be placed.
showPositiveSign	boolean	false	Set this to true to show the + character on positive values.

Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.

License

react-native-currency-input is released under the MIT license. See LICENSE for details.

Any question or support will welcome.