svelte-currency-format-input

An interactive form input that instantly transforms numerical entries into localized currency formats while you type

Features

• Utilizes Intl.NumberFormat to incorporate localization for currency denominations and implements input masking.
• Formats values can be positive and negative.
• Basic default styling, simple to customize.
• Simple PROPS.

Usage

npm install @adityarizqi/svelte-currency-format-input --save

or if you are using yarn

yarn add @adityarizqi/svelte-currency-format-input

Then you need to import this library into your application.

<script lang="ts">
  import CurrencyFormatInput from '@adityarizqi7/svelte-currency-format-input';
</script>

<CurrencyFormatInput name="total" placeholder='Your Placeholder' value={666} locale="id-ID" currency="IDR" />

How it works

Upon form submission, you obtain either unformatted or formatted values from two <input /> elements. This is essentially the underlying structure of <CurrencyFormatInput />:

<div class="currencyInput">
  <!-- Unformatted value -->
  <input
    class="currencyInput__unformatted"
    type="hidden"
    name="total"
    value="-322.76"
  />

  <!-- Formatted value -->
  <input
    class="currencyInput__formatted"
    type="text"
    name="formatted-total"
    value="€ -322,76"
  />
</div>

PROPS

Option | Type | Default | Description | ----------------- | --------------- | ----------- | ----------- | value | number | undefined | Initial value. If left undefined a formatted value of 0 is visible as a placeholder | locale | string | en-US | Overrides default locale. Examples | currency | string | USD | Overrides default currency. Examples | name | string | total | Applies the name to the input fields for unformatted (e.g [name=total]) and formatted (e.g. [name=formatted-total]) values | fractionDigits | number | 2 | Sets maximumFractionDigits in Intl.NumberFormat() constructor used for formatting the currency. Supported digits: 0 to 20 | placeholder | string number null | 0 | A string will override the default placeholder. A number will override it by formatting it to the set currency. Setting it to null will not show a placeholder | inputClasses | object | See below | Selectively overrides any class names passed | required | boolean | false | Marks the inputs as required | disabled | boolean | false | Marks the inputs as disabled | isZeroNullish | boolean | false | If true and when the value is 0, it will override the default placeholder and render the formatted value in the field like any other value. autocomplete | string | undefined | Sets the autocomplete attribute. Accepts any valid HTML autocomplete attribute values | isNegativeInput | boolean | true | If false, forces formatting only to positive values and ignores --positive and --negative styling modifiers | onValueChange | Callback | undefined | Runs a callback function after the value changes |

Styling Component

There are two methods for customizing the styling of the input:

1. Providing your own CSS classes
2. Modifying the styles by overriding the existing class names

You have the ability to override any of the class names by passing an object to inputClasses that includes one or more of these properties:

interface InputClasses {
  wrapper?: string; // The <div> encapsulates the two <input> elements.
  unformatted?: string; // The <input type="hidden"> element encapsulates the unformatted value.
  formatted?: string; // The <input type="text"> element encapsulates the formatted value.
  formattedPositive?: string; // Class applied when the formatted input represents a positive value.
  formattedNegative?: string; // Class applied when the formatted input represents a negative value.
  formattedZero?: string; // Class applied when the formatted input represents a zero value.
}

You can usage (with Tailwind CSS as an example):

<CurrencyFormatInput name="total" value="{322.76}" inputClasses={
  { 
    wrapper: "py-1 text-sm text-gray-800 border border-gray-300 rounded-md",
    formatted: 'text-gray-800 border-0 bg-white max-w-full',
    formattedPositive: 'text-green-700',
    formattedNegative: 'text-red-700'
  }
} />

Alternatively you can write your own CSS by overriding the default styles which use BEM naming conventions. To do so apply your styles as shown below:

<div class="my-currency-input">
  <CurrencyFormatInput name="total" value="{420.69}" />
</div>

<style>
  /* Container */
  div.my-currency-input :global(div.currencyInput) { /* ... */ }

  /* Formatted input */
  div.my-currency-input :global(input.currencyInput__formatted) { /* ... */ }

  /* Formatted input when the it's disabled */
  div.my-currency-input :global(input.currencyInput__formatted:disabled) { /* ... */ }

  /* Formatted input when the value is zero */
  div.my-currency-input :global(input.currencyInput__formatted--zero) { /* ... */ }

  /* Formatted input when the value is positive */
  div.my-currency-input :global(input.currencyInput__formatted--positive) { /* ... */ }

  /* Formatted input when the value is negative */
  div.my-currency-input :global(input.currencyInput__formatted--negative) { /* ... */ }
</style>

Contributing

Here are ways you can contribute:

• Discovered a bug? Create a new issue
• Provide comments or upvote existing issues
• Submit a pull request

Developing

This package was generated with SvelteKit. Install dependencies with npm install, then start a development server:

npm run dev

# or start the server and open the app in a new browser tab
npm run dev -- --open

Integration tests

The component is tested using Playwright. You can find the tests in tests/svelte-currency-format-input.test.ts

To run all tests on Chromium, Firefox and Webkit:

npm run test

To run all tests on a specific browser (e.g. Webkit):

npx playwright test --project=webkit

Additional debug commands can be found on Playwright's documentation.