Postcss-rtl-logical-properties NPM

🌍 postcss-rtl-logical-properties

✨ postcss-rtl-logical-properties is a PostCSS plugin that replaces physical CSS properties (left, right, margin-left, padding-right, etc.) with logical CSS properties (start, end, margin-inline-start, etc.) for better RTL support with reduced CSS size.

🚀 Features

Converts physical direction properties to logical properties automatically.
Reduces final CSS size by eliminating redundant LTR/RTL selector duplication.
Compatible with postcss-rtl and rtlcss for comprehensive RTL support.
ESM & CommonJS support for modern environments.
Zero dependencies – lightweight and fast.

📦 Installation

npm install postcss-rtl-logical-properties --save-dev

🔧 Usage

ESM Example

Add the plugin to your PostCSS configuration:

import postcss from "postcss";
import postcssRtlLogicalProperties from "postcss-rtl-logical-properties";
import postcssRTL from "postcss-rtl";

const css = `
.foo {
    margin-left: 10px;
    margin-right: 20px;
    border-radius: 5px 10px 15px 20px;
    }
`;

postcss([
  plugin,
  postcssRTL({
    blacklist: plugin.ignoreDeclarationList,
  }),
])
  .process(css, { from: false })
  .then((result) => {
    console.log(result.css);
  });

const postcssRtlLogicalProperties = require("postcss-rtl-logical-properties");

module.exports = {
  plugins: [postcssRtlLogicalProperties()],
};

🌍 Usage with `postcss-rtl`

For multi-direction support (LTR + RTL) using the [dir] attribute:

import postcss from "postcss";
import plugin from "postcss-rtl-logical-properties";
import postcssRTL from "postcss-rtl";

const css = `
.foo {
    margin-left: 10px;
    margin-right: 20px;
    border-radius: 5px 10px 15px 20px;
}
`;

postcss([plugin, postcssRTL({ blacklist: plugin.ignoreDeclarationList })])
  .process(css, { from: false })
  .then((result) => console.log(result.css));

⚡ CommonJS Example (One-Way Direction Support)

const postcssRtlLogicalProperties = require("postcss-rtl-logical-properties");
const rtlcss = require("rtlcss");
const postcss = require("postcss");

const result = postcss([postcssRtlLogicalProperties(), rtlcss()]).process(`
    .test {
        padding-left: 10px;
        border-right: 20px;
        margin: 10px 1px 10px 29px;
    }
`);

console.log(result.css);

🛠 Plugin Options

Option	Description	Default
`hDirection`	Sets the horizontal writing direction (LTR/RTL)	`LeftToRight`
`vDirection`	Sets the vertical writing direction (TTB/BTB)	`TopToBottom`

🎯 Supported Properties

This plugin replaces the following physical properties with their logical counterparts:

Padding: padding-left, padding-right
Margin: margin-left, margin-right
Border: border-left, border-right, border-left-width, border-right-width, border-left-color, border-right-color, border-left-style, border-right-style
Radius: border-bottom-left-radius, border-bottom-right-radius, border-top-left-radius, border-top-right-radius
Positioning: left, right
Float & Clear: float, clear
Text Alignment: text-align

🌍 Browser Support

✅ Global support: ~89% (Can I Use)

❗ Note: This plugin does not transform complex properties like transform, background-position, or border-radius. For these, use rtlcss.

🤔 Why Use This Plugin?

Many RTL processors like postcss-rtlcss generate duplicate selectors with [dir] attributes, significantly increasing CSS file size. This plugin eliminates redundant rules by leveraging native logical properties, reducing final CSS size while maintaining full RTL support.