PostHTML

PostHTML is a tool for transforming HTML/XML with JS plugins. PostHTML itself is very small. It includes only a HTML parser, a HTML node tree API and a node tree stringifier.

All HTML transformations are made by plugins. And these plugins are just small plain JS functions, which receive a HTML node tree, transform it, and return a modified tree.

For more detailed information about PostHTML in general take a look at the docs.

Dependencies

Name	Status	Description
posthtml-parser		Parser HTML/XML to PostHTMLTree
posthtml-render		Render PostHTMLTree to HTML/XML

Create to your project

npm init posthtml

Install

npm i -D posthtml

Usage

API

Sync

import posthtml from 'posthtml'

const html = `
  <component>
    <title>Super Title</title>
    <text>Awesome Text</text>
  </component>
`

const result = posthtml()
  .use(require('posthtml-custom-elements')())
  .process(html, { sync: true })
  .html

console.log(result)

<div class="component">
  <div class="title">Super Title</div>
  <div class="text">Awesome Text</div>
</div>

⚠️ Async Plugins can't be used in sync mode and will throw an Error. It's recommended to use PostHTML asynchronously whenever possible.

Async

import posthtml from 'posthtml'

const html = `
  <html>
    <body>
      <p class="wow">OMG</p>
    </body>
  </html>
`

posthtml(
  [
    require('posthtml-to-svg-tags')(),
    require('posthtml-extend-attrs')({
      attrsTree: {
        '.wow' : {
          id: 'wow_id',
          fill: '#4A83B4',
          'fill-rule': 'evenodd',
          'font-family': 'Verdana'
        }
      }
    })
  ])
  .process(html/*, options */)
  .then((result) =>  console.log(result.html))

<svg xmlns="http://www.w3.org/2000/svg">
  <text
    class="wow"
    id="wow_id"
    fill="#4A83B4"
    fill-rule="evenodd" font-family="Verdana">
      OMG
  </text>
</svg>

Directives

import posthtml from 'posthtml'

const php = `
  <component>
    <title><?php echo $title; ?></title>
    <text><?php echo $article; ?></text>
  </component>
`

const result = posthtml()
  .use(require('posthtml-custom-elements')())
  .process(html, {
    directives: [
      { name: '?php', start: '<', end: '>' }
    ]
  })
  .html

console.log(result)

<div class="component">
  <div class="title"><?php echo $title; ?></div>
  <div class="text"><?php echo $article; ?></div>
</div>

CLI

npm i posthtml-cli

"scripts": {
  "posthtml": "posthtml -o output.html -i input.html -c config.json"
}

npm run posthtml

Gulp

npm i -D gulp-posthtml

import tap from 'gulp-tap'
import posthtml from 'gulp-posthtml'
import { task, src, dest } from 'gulp'

task('html', () => {
  let path

  const plugins = [ require('posthtml-include')({ root: `${path}` }) ]
  const options = {}

  src('src/**/*.html')
    .pipe(tap((file) => path = file.path))
    .pipe(posthtml(plugins, options))
    .pipe(dest('build/'))
})

Check project-stub for an example with Gulp

Grunt

npm i -D grunt-posthtml

posthtml: {
  options: {
    use: [
      require('posthtml-doctype')({ doctype: 'HTML 5' }),
      require('posthtml-include')({ root: './', encoding: 'utf-8' })
    ]
  },
  build: {
    files: [
      {
        dot: true,
        cwd: 'html/',
        src: ['*.html'],
        dest: 'tmp/',
        expand: true,
      }
    ]
  }
}

Webpack

npm i -D html-loader posthtml-loader

v1.x

webpack.config.js

const config = {
  module: {
    loaders: [
      {
        test: /\.html$/,
        loader: 'html!posthtml'
      }
    ]
  },
  posthtml: (ctx) => ({
    parser: require('posthtml-pug'),
    plugins: [
      require('posthtml-bem')()
    ]
  })
}

export default config

v2.x

webpack.config.js

import { LoaderOptionsPlugin } from 'webpack'

const config = {
  module: {
    rules: [
      {
        test: /\.html$/,
        use: [
          {
            loader: 'html-loader',
            options: { minimize: true }
          },
          {
            loader: 'posthtml-loader'
          }
        ]
      }
    ]
  },
  plugins: [
    new LoaderOptionsPlugin({
      options: {
        posthtml(ctx) {
          return {
            parser: require('posthtml-pug'),
            plugins: [
              require('posthtml-bem')()
            ]
          }
        }
      }
    })
  ]
}

export default config

Rollup

$ npm i rollup-plugin-posthtml -D
# or
$ npm i rollup-plugin-posthtml-template -D

import { join } from 'path';

import posthtml from 'rollup-plugin-posthtml-template';
// or
// import posthtml from 'rollup-plugin-posthtml';

import sugarml from 'posthtml-sugarml';  // npm i posthtml-sugarml -D
import include from 'posthtml-include';  // npm i posthtml-include -D

export default {
  entry: join(__dirname, 'main.js'),
  dest: join(__dirname, 'bundle.js'),
  format: 'iife',
  plugins: [
    posthtml({
      parser: sugarml(),
      plugins: [include()],
      template: true  // only rollup-plugin-posthtml-template
    })
  ]
};

Parser

import pug from 'posthtml-pug'

posthtml().process(html, { parser: pug(options) }).then((result) => result.html)

Name	Status	Description
posthtml-pug		Pug Parser
sugarml		SugarML Parser

Plugins

In case you want to develop your own plugin, we recommend using posthtml-plugin-starter to get started.

TEXT

Name	Status	Description
posthtml-md		Easily use context-sensitive markdown within HTML
posthtml-toc		Table of contents
posthtml-lorem		Add lorem ipsum placeholder text to any document
posthtml-retext		Extensible system for analysing and manipulating natural language
prevent-widows		Prevent widows from appearing at the end of paragraphs
posthtml-richtypo		Process HTML node text with Richtypo

HTML

Name	Status	Description
posthtml-doctype		Set !DOCTYPE
posthtml-head-elements		Include head elements from JSON file
posthtml-include		Include HTML
posthtml-modules		Include and process HTML
posthtml-extend		Extend Layout (Pug-like)
posthtml-extend-attrs		Extend Attrs
posthtml-expressions		Template Expressions
posthtml-inline-assets		Inline external scripts, styles, and images
posthtml-static-react		Render custom elements as static React components
posthtml-custom-elements		Use custom elements
posthtml-web-component		Web Component server-side rendering, Component as a Service (CaaS)
posthtml-spaceless		Remove whitespace between HTML tags
posthtml-cache		Add a nanoid to links in your tags
posthtml-highlight		Syntax highlight code elements
posthtml-pseudo		Add pseudo selector class names to elements
posthtml-noopener		Add rel="noopener noreferrer" to links that open in new tab
posthtml-noscript		Insert noscript content when JavaScript is disabled
posthtml-hash		Hash static CSS/JS assets
posthtml-insert-at		Append/prepend HTML to a selector
posthtml-plugin-remove-duplicates		Remove duplicated tags
posthtml-plugin-link-preload		Add preload/prefetch tags (or return equivalent headers)
posthtml-prism		Code syntax highlighting with Prism
posthtml-url-parameters		Add parameters to URLs
posthtml-safe-class-names		Replace escaped characters in class names and CSS selectors
posthtml-fetch		Fetch and render remote content
posthtml-mso		Makes it easy to write Outlook conditionals in HTML emails
posthtml-postcss-merge-longhand		Merge longhand inline CSS into shorthand
posthtml-markdownit		Transform Markdown using markdown-it
posthtml-extra-attributes		Add new attributes to elements in your HTML
posthtml-sri		Adds subresource integrity (SRI) attributes.

CSS

Name	Status	Description
posthtml-bem		Support BEM naming in html structure
posthtml-postcss		Use PostCSS in HTML document
posthtml-px2rem		Change px to rem in Inline CSS
posthtml-css-modules		Use CSS modules in HTML
posthtml-postcss-modules		CSS Modules in html
posthtml-classes		Get a list of classes from HTML
posthtml-prefix-class		Prefix class names
posthtml-modular-css		Make CSS modular
posthtml-inline-css		CSS Inliner
posthtml-collect-styles		Collect styles from html and put it in the head
posthtml-collect-inline-styles		Collect inline styles and insert to head tag
posthtml-style-expantion		PostHTML plugin expand link rel="stylesheet".
posthtml-style-to-file		Save HTML style nodes and attributes to CSS file
posthtml-color-shorthand-hex-to-six-digit		Enforce all hex color codes to be 6-char long
posthtml-minify-classnames		Rewrites classnames and ids inside of html and css files to reduce file size.

IMG & SVG

Name	Status	Description
posthtml-img-autosize		Auto setting the width and height of <img>
posthtml-to-svg-tags		Convert html tags to svg equivalents
posthtml-webp		Add WebP support for images
posthtml-favicons		Generate Favicons and add related tags
posthtml-inline-svg		Inline svg icons in HTML
posthtml-inline-favicon		Inline favicons in HTML

Accessibility

Name	Status	Description
posthtml-aria-tabs		Write accessible tabs with minimal markup
posthtml-alt-always		Always add alt attribute for images that don't have it
posthtml-schemas		Add microdata to your HTML

Optimization

Name	Status	Description
posthtml-shorten		Shorten URLs in HTML
posthtml-uglify		Shorten CSS in HTML
posthtml-minifier		Minify HTML
posthtml-remove-attributes		Remove attributes unconditionally or with content match
posthtml-remove-tags		Remove tags with content match
posthtml-remove-duplicates		Remove duplicate elements from your html
posthtml-transformer		Process HTML by directives in node attrs, such as inline scripts and styles, remove useless tags, concat scripts and styles etc.
htmlnano		HTML Minifier
posthtml-link-noreferrer		Add `rel="noopener"` and `rel="noreferrer"` to all links that contain the attribute `target="_blank"`
posthtml-lazyload		Add native lazyload attribute
posthtml-postcss-treeshaker		Tree shake styles for classes and ids in `style` tag
posthtml-external-link		Add `rel="external noopenner nofollow"` and `target="_blank"` to all external links

Workflow

Name	Status	Description
posthtml-load-plugins		Autoload Plugins
posthtml-load-options		Autoload Options (Parser && Render)
posthtml-load-config		Autoload Config (Plugins && Options)
posthtml-w3c		Validate HTML with W3C Validation
posthtml-hint		Lint HTML with HTML Hint
posthtml-tidy		Sanitize HTML with HTML Tidy

Middleware

Name	Status	Description
koa-posthtml		Koa Middleware
hapi-posthtml		Hapi Plugin
express-posthtml		Express Middleware
electron-posthtml		Electron Plugin
metalsmith-posthtml		Metalsmith Plugin