HTML Build Attributes

ES2018, TypeScript 5, Node 16

---

Generate a string of HTML attributes.

Install

Using NPM:

npm install @mcaskill/html-build-attributes

Upgrade

This package follows semantic versioning, which means breaking changes may occur between major releases.

Usage

Browse /examples for a list of demonstrations and enhancements.

The following example demonstrates the default module:

import {
  composeAttribute,
  composeAttributes,
  escapeAttributeValue,
  filterAttributeValue,
} from '@mcaskill/html-build-attributes/default.js';

const inputAttrs = {
  'type':           'file',
  'name':           'avatar',
  'multiple':       true,
  'disabled':       false,
  'accept':         [ 'image/png', 'image/jpeg' ],
  'data-type':      null,
  'data-max-files': 3,
};

console.log(`<input ${composeAttributes(inputAttrs)}>`);
// → <input type="file" name="avatar" multiple accept="image/png,image/jpeg" data-max-files="3">

const buttonAttrs = {
  'type':              'button',
  'id':                'ThemeLight',
  'aria-labelledby':   [ 'ThemeLight', 'ThemeLbl' ],
  'aria-pressed':      false,
  'data-toggle-theme': true,
};

console.log(`<button ${composeAttributes(buttonAttrs)}>Light</button>`);
// → <button type="button" id="ThemeLight" aria-labelledby="ThemeLight ThemeLbl" aria-pressed="false" data-toggle-theme>Light</button>

composeAttributes({ class: [], disabled: false });
// → null

composeAttribute('class', 'avatar');
// → class="avatar"

composeAttribute('aria-hidden', true);
// → aria-hidden="true"

composeAttribute('required', true);
// → required

composeAttribute('required', false);
// → null

filterAttributeValue({ id: 1, name: 'Tim' });
// → {"id":1,"name":"Tim"}

escapeAttributeValue('{"id":1,"name":"Tim"}');
// → {&quot;id&quot;:1,&quot;name&quot;:&quot;Tim&quot;}

API

View API documentation

Default Module

@mcaskill/html-build-attributes/default.js

A preset instance of Composer is available (featured above). It's equiped with basic filters and escape of common HTML entities, which should cover most HTML tags.

• composeAttribute(name: string, value: unknown): string|null

  A reference to Composer#composeAttribute() from which you can generate a string of one HTML attribute.

• composeAttributes(attributes: object<string, unknown>): string|null

  A reference to Composer#composeAttributes() from which you can generate a string of many HTML attributes.

• escapeAttributeValue(value: string): string

  A reference to Composer#escapeAttributeValue() from which you can convert special characters to their corresponding HTML entities.

• filterAttributeValue(value: unknown, name?: string): string|boolean|null

  A reference to Composer#filterAttributeValue() from which you can approve, reject, and parse a value for an HTML attribute.

Benchmarks

Via the /benchmarks directory with Node 16.15.1.

Below are results between the current and original implementations against a few simple use cases that cover most HTML attributes:

# Set #1
  Original  x 1,327,189 ops/sec ±0.14% (94 runs sampled)
  Current   x 995,463 ops/sec ±0.09% (98 runs sampled)

# Set #2
  Original  x 1,643,401 ops/sec ±0.08% (101 runs sampled)
  Current   x 1,191,994 ops/sec ±0.13% (101 runs sampled)

# Set #3
  Original  x 947,281 ops/sec ±0.07% (101 runs sampled)
  Current   x 924,929 ops/sec ±0.06% (98 runs sampled)

Implementations in other languages

• mcaskill/php-html-build-attributes — A PHP implementation of this package.

Related

• classnames — A simple utility for conditionally joining CSS class names together.
• clsx — A faster & smaller drop-in replacement for the classnames module.
• he — A robust HTML entity encoder/decoder.
• lodash.escape — A basic HTML entity encoder.
• posthtml-attrs-parser — A PostHTML helper that provides an improved API to work with a tag's attributes.
• fabianmichael/kirby-template-attributes — A PHP plugin for Kirby that provides a helper to compose attribute in templates.

See Also

• Ambiguous ampersands, 2011, by Mathias Bynens