Input Number

Input Number - input idea for Shop systems or so.

Contents

• Overview
• Installation
• Basic usage
• Configuration Options
• JavaScript API
• Events
• Common Patterns
• License

Overview

The Input Number component provides a numeric input field with increment and decrement buttons. It's ideal for quantity selectors, cart systems, or any interface requiring numeric input with step controls.

Key Features:

• Numeric input with step controls
• Increment/decrement buttons
• Min/max value constraints
• Custom step values
• Programmatic control via JavaScript API
• Event system for value tracking
• Disabled state support

Installation

To get started, install Input Number plugin via npm, else you can skip this step if you are already using Preline UI as a package.

npm i @preline/input-number

CSS

Use @source to register the plugin's JavaScript path for Tailwind CSS scanning, then @import the plugin's CSS files into your Tailwind CSS file.

@import "tailwindcss";

/* @preline/input-number */
@source "../node_modules/@preline/input-number/*.js";
@import "./node_modules/@preline/input-number/variants.css";
@import "./node_modules/@preline/input-number/theme.css";

JavaScript

Include the JavaScript that powers the interactive elements near the end of your </body> tag:

<script src="./node_modules/@preline/input-number/index.js"></script>

Manual Initialization

Use the non-auto entry if you need manual initialization. In this mode, automatic initialization on page load is not included, so the component should be initialized explicitly.

<script type="module">
  import HSInputNumber from "@preline/input-number/non-auto.mjs";

  new HSInputNumber(document.querySelector("#input-number"));
</script>

Via Bundler

When using a bundler (Vite, webpack, etc.), import the plugin directly as an ES module.

@preline/input-number is the auto-init entry: it scans the DOM and initializes matching elements automatically.

import "@preline/input-number";

@preline/input-number/non-auto is the manual entry: use it when you want explicit control over when initialization happens, either via autoInit() or by creating a specific instance yourself.

import HSInputNumber from "@preline/input-number/non-auto";

HSInputNumber.autoInit();

// Or initialize a specific element manually
const el = document.querySelector("#input-number");
if (el) new HSInputNumber(el);

TypeScript

This package ships with TypeScript type definitions. No additional @types/ package is needed.

Basic usage

The following example demonstrates the minimal HTML structure required for an input number component. This is a base template without custom styling - you can apply your own CSS classes and styles as needed. The component includes an input field and increment/decrement buttons.

<div data-hs-input-number>
  <input type="text" aria-roledescription="Number field" value="1" data-hs-input-number-input>
  <button type="button" class="" tabindex="-1" aria-label="Decrease" data-hs-input-number-decrement>
    Minus
  </button>
  <button type="button" class="" tabindex="-1" aria-label="Increase" data-hs-input-number-increment>
    Add
  </button>
</div>

Structure Requirements:

• data-hs-input-number: Required on the container element
• data-hs-input-number-input: Required on the input element
• data-hs-input-number-increment: Required on the increment button
• data-hs-input-number-decrement: Required on the decrement button
• Proper ARIA attributes (aria-roledescription, aria-label)

Initial State:

• Input field contains the initial value (e.g., value="1")
• Buttons are enabled/disabled based on min/max constraints

Configuration Options

Data Options

Data options are specified in the data-hs-input-number attribute.

| Attribute | Target Element | Type | Default | Description | | --- | --- | --- | --- | --- | | data-hs-input-number | Container | - | - | Activate an Input Number by specifying on an element. Should be added to the container. | | :min | Inside data-hs-input-number | number | "-Infinity" | 0 | Defines the minimum possible value. -Infinity allows you to enter negative values without restrictions. | | :max | Inside data-hs-input-number | number | null | null | Defines the maximum possible value. null means no maximum limit. | | :step | Inside data-hs-input-number | number | 1 | Determines the step by which the value will increase or decrease when buttons are clicked. | | :forceBlankValue | Inside data-hs-input-number | boolean | false | Whether the input value should be blank when the value isn't set. When true, empty input shows blank instead of default value. |

Example:

<div data-hs-input-number='{
  "min": 0,
  "max": 100,
  "step": 5,
  "forceBlankValue": false
}'>
  <!-- Input and buttons -->
</div>

Required CSS Classes / Data Attributes

These data attributes define the structure and must be present for the input number to function.

| Data Attribute | Required On | Purpose | | --- | --- | --- | | data-hs-input-number-input | Input element | Identifies the numeric input field | | data-hs-input-number-increment | Button element | Identifies the increment button | | data-hs-input-number-decrement | Button element | Identifies the decrement button |

Tailwind Modifiers

| Name | Description | | --- | --- | | hs-input-number-disabled:* | A modifier that allows you to set Tailwind classes when input's value is set to zero (or minimum value). |

JavaScript API

The HSInputNumber object is available in the global window object after the plugin is loaded.

Instance Methods

These methods are called on an input number instance.

| Method | Parameters | Return Type | Description | | --- | --- | --- | --- | | destroy() | None | void | Destroys the input number instance, removes all generated markup, classes, and event listeners. Use when removing input number from DOM. |

Static Methods

These methods are called directly on the HSInputNumber class.

| Method | Parameters | Return Type | Description | | --- | --- | --- | --- | | HSInputNumber.getInstance(target, isInstance) | target: HTMLElement \| string (CSS selector)isInstance: boolean (optional) | HSInputNumber \| { id: number, element: HSInputNumber } \| null | Returns the input number instance associated with the target. If isInstance is true, returns collection item object { id, element } where element is the HSInputNumber instance. If isInstance is false or omitted, returns the HSInputNumber instance directly. Returns null if input number instance is not found. |

Usage Examples

Example 1: Destroying input number instance

const instance = HSInputNumber.getInstance('#hs-input-number', true);

if (instance) {
  const { element } = instance;
  const destroyBtn = document.querySelector('#hs-destroy-btn');

  destroyBtn.addEventListener('click', () => {
    element.destroy();
  });
}

Example 2: Getting instance and accessing properties

// Get the input number instance
const instance = HSInputNumber.getInstance('#hs-input-number', true);

if (instance) {
  const { element } = instance;

  // Access instance properties
  console.log('Current value:', element.inputValue);
  console.log('Min value:', element.minInputValue);
  console.log('Max value:', element.maxInputValue);
  console.log('Step:', element.step);

  // Clean up when removing from DOM
  function removeInputNumber() {
    element.destroy();
  }
}

Example 3: Destroying input number instance

const instance = HSInputNumber.getInstance('#hs-input-number', true);

if (instance) {
  const { element } = instance;
  const removeBtn = document.querySelector('#hs-remove-btn');

  removeBtn.addEventListener('click', () => {
    // Clean up before removing from DOM
    element.destroy();
    // Now safe to remove the element
    document.querySelector('#hs-input-number').remove();
  });
}

Events

Input number instances emit events that can be listened to for value tracking and custom behavior.

| Event Name | When Fired | Callback Parameter | Description | | --- | --- | --- | --- | | on:change | When input value was changed | { inputValue: number } | Fires when the input value changes (via buttons or direct input). Returns an object with the inputValue containing the current numeric value. |

Event Usage Example

// Get input number instance
const instance = HSInputNumber.getInstance('#hs-input-number', true);

if (instance) {
  const { element } = instance;

  // Listen to change event
  element.on('change', ({ inputValue }) => {
    console.log('Input value changed:', inputValue);
    // Perform actions after value changes
    // e.g., update cart, calculate totals, validate
  });
}

Common Patterns

Pattern 1: Quantity Selector

Create a quantity selector for shopping carts.

<div data-hs-input-number='{
  "min": 1,
  "max": 99,
  "step": 1
}'>
  <input type="text" value="1" data-hs-input-number-input>
  <button data-hs-input-number-decrement>-</button>
  <button data-hs-input-number-increment>+</button>
</div>

Pattern 2: Negative Values Allowed

Allow negative values by setting min to -Infinity.

<div data-hs-input-number='{
  "min": "-Infinity",
  "max": null,
  "step": 1
}'>
  <!-- Input and buttons -->
</div>

Pattern 3: Handling Value Changes

Track value changes with event listener.

<div id="hs-input-number-first" data-hs-input-number>
  <input type="text" value="1" data-hs-input-number-input>
  <button data-hs-input-number-decrement>-</button>
  <button data-hs-input-number-increment>+</button>
</div>

<script>
  const instance = HSInputNumber.getInstance('#hs-input-number-first', true);
  
  if (instance) {
    const { element } = instance;

    element.on('change', ({ inputValue }) => {
      console.log('Quantity:', inputValue);
      // Update cart or perform other actions
    });
  }
</script>

License

Copyright (c) 2026 Preline Labs.

Licensed under the MIT License.