README

Safe Class Names

Replace escaped characters in class names and CSS selectors

Introduction

This plugin replaces escaped characters in class names from your <style> tags and inside class="" attributes with safe characters, that do not need escaping.

By default, it replaces:

\: and \/ with -
\% with pc
\. with _

See the full list of replacements.

But... why?

So you can use those cool Tailwind CSS selectors in HTML emails. 😎

Escaped characters in CSS selectors or HTML class names are not supported by all email clients (currently Gmail being the biggest one), so you can use this plugin to replace them with safe alternatives.

Install

$ npm i posthtml posthtml-safe-class-names

Usage

Consider example.html:

<!DOCTYPE html>
<html>
<head>
  <style>
    .w-3\/5 {
      width: 60%;
    }
    
    /* JIT arbitrary values are also supported */
    .bg-\[\#1da1f1\] {
      background-color: #1da1f1;
    }

    @media (max-width: 600px) {
      .sm\:w-1\/2 {
        width: 50%;
      }
    }
  </style>
</head>
<body>
  <div class="w-3/5 sm:w-1/2 bg-[#1da1f1]">Lorem ipsum</div>
</body>
</html>

const fs = require('fs')
const posthtml = require('posthtml')
const safeClassNames = require('posthtml-safe-class-names')

const source = fs.readFileSync('./example.html')

posthtml([
    safeClassNames()
  ])
  .process(source)
  .then(result => fs.writeFileSync('./after.html', result.html))

Result:

<!DOCTYPE html>
<html>
<head>
  <style>
    .sm-w-3-5 {
      width: 60%;
    }

    .bg-_1da1f1 {
      background-color: #1da1f1;
    }

    @media (max-width: 600px) {
      .sm-w-1-2 {
        width: 50%;
      }
    }
  </style>
</head>
<body>
  <div class="w-3-5 sm-w-1-2 bg-_1da1f1">Lorem ipsum</div>
</body>
</html>

Options

`replacements`

The plugin accepts an options object where you can define character replacement mappings:

{
  ':': '-',
  '\/': '-',
  '%': 'pc',
  '.': '_',
  // ...
}