How to make a currency mask

[lpepinelli]

• I'm submitting a ...
  [    ] bug report
  [    ] feature request
  [    ] question about the decisions made in the repository
  [ x ] question about how to use this project

• Summary
  I'm trying to make a simple number mask to currency values.

<Space direction="vertical">
  <label>Entrada</label>
    <MaskedInput
      autoComplete="off"
      placeholder = "Entrada"
      mask={
        React.useMemo<MaskType>(() => [
          {
            mask: 'R$ num',
            lazy: true,
            blocks: {
              num: {
                mask: Number,
                thousandsSeparator: '.',
                padFractionalZeros: true
              }
            }
          }
        ], [])
      }
    />
</Space>

But that way only one digit appears and throws this warning on the console. What am I doing wrong?

• Other information (e.g. detailed explanation, stacktraces, related issues, suggestions how to fix, links for us to have context, eg. StackOverflow, personal fork, etc.)

I am following this documentation: https://imask.js.org/

Thanks!

[augustosnk12]

@lpepinelli did you find any solution?

[lpepinelli]

Not with this library, not yet. But I found an alternative with typescript, regex and antd input component.

export const currencyMask = (value: string) => {
  let valueFormatted = value
  valueFormatted = valueFormatted.replace(/\D/g, '')
  valueFormatted = valueFormatted.replace(/(\d)(\d{2})$/, '$1,$2')
  valueFormatted = valueFormatted.replace(/(?=(\d{3})+(\D))\B/g, '.')
  return {
    maskedValue: valueFormatted,
    unmaskedValue: Number(valueFormatted.replace('.', '').replace(',', '.'))
  }
}

<Input
  prefix='R$'
  placeholder="Entrada"
  autoComplete='off'
  value={entradaInput}
  onChange={({ target }) => handleEntradaChange(target.value)} />

const handleEntradaChange = (value: string) => {
  setEntradaInput(currencyMask(value).maskedValue)
  const unmaskedValue = currencyMask(value).unmaskedValue
  console.log(unmaskedValue)
}

[antoniopresto]

You must use useMeme in the component body

[renerlemes]

@antoniopresto how to use the example that working of @lpepinelli with useMemo?

[renerlemes]

@lpepinelli How would this function look like when I type 1, it starts formatting from right to left, that is, it would look like this: 0.01. When I typed 15 it would format to 0.15?

[lpepinelli]

Hi @renerlemes

If you add a "padStart" to the function you will have the behavior that you want.

export const currencyMask = (value: string) => {
  let valueFormatted = value
  valueFormatted = valueFormatted.replace(/\D/g, '')

  // Add a leading zero for numbers with one or two digits
  valueFormatted = valueFormatted.padStart(3, '0')

  valueFormatted = valueFormatted.replace(/(\d{1})(\d{2})$/, '$1,$2')
  valueFormatted = valueFormatted.replace(/(?=(\d{3})+(\D))\B/g, '.')

  return {
    maskedValue: valueFormatted,
    unmaskedValue: Number(valueFormatted.replace('.', '').replace(',', '.'))
  }
}

I don't have my project working here to test, but I think it will work.

[renerlemes]

@lpepinelli the code you suggested did not work. See the image below. But I made a small change and it worked.

export const currencyMask = (value: string) => {

let valueFormatted = value;

valueFormatted = valueFormatted.replace(/\D/g, "");

valueFormatted = valueFormatted.padStart(3, "0");

valueFormatted = valueFormatted.replace(/(\d{1})(\d{2})$/, "$1,$2");
valueFormatted = valueFormatted.replace(/(?=(\d{3})+(\D))\B/g, ".");

let beforeComma = valueFormatted.split(",")[0];

if (beforeComma === "00" || (beforeComma.length === 2 && beforeComma[0] === "0" && beforeComma[1] !== "0")) {
	valueFormatted = valueFormatted.slice(1);
}

return {
    maskedValue: valueFormatted,
    unmaskedValue: Number(valueFormatted.replace('.', '').replace(',', '.'))
}