PostHTML is a tool for transforming HTML/XML with JavaScript plugins. It allows you to process HTML files using a variety of plugins to perform tasks such as minification, templating, and more.
HTML Transformation
This feature allows you to transform HTML elements. In this example, all <div> tags are transformed into <span> tags.
const posthtml = require('posthtml');
const html = '<div class="foo">Hello World</div>';
posthtml()
.use(tree => {
tree.match({ tag: 'div' }, node => {
node.tag = 'span';
return node;
});
})
.process(html)
.then(result => console.log(result.html));HTML Minification
This feature allows you to minify HTML content. The example demonstrates how to collapse whitespace in the HTML string.
const posthtml = require('posthtml');
const html = '<div class="foo"> Hello World </div>';
const posthtmlMinifier = require('posthtml-minifier');
posthtml([posthtmlMinifier({ collapseWhitespace: true })])
.process(html)
.then(result => console.log(result.html));Templating
This feature allows you to use templating within your HTML. The example shows how to replace a placeholder with a dynamic value.
const posthtml = require('posthtml');
const expressions = require('posthtml-expressions');
const html = '<div>{{ message }}</div>';
posthtml([expressions({ locals: { message: 'Hello World' } })])
.process(html)
.then(result => console.log(result.html));html-minifier is a highly configurable, well-tested, JavaScript-based HTML minifier. It focuses on minifying HTML content, similar to the minification feature in PostHTML, but does not offer the same level of extensibility with plugins.
Cheerio is a fast, flexible, and lean implementation of core jQuery designed specifically for the server. It allows you to manipulate HTML and XML documents with a jQuery-like syntax. While it offers powerful DOM manipulation capabilities, it does not provide the same plugin-based architecture as PostHTML.
jsdom is a JavaScript implementation of the WHATWG DOM and HTML standards, primarily intended for use with Node.js. It allows you to create and manipulate a DOM tree, similar to PostHTML, but is more focused on providing a complete DOM environment rather than a plugin-based transformation system.
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.
Simple example
var posthtml = require('posthtml');
var html = '<myComponent><myTitle>Super Title</myTitle><myText>Awesome Text</myText></myComponent>';
posthtml()
.use(require('posthtml-custom-elements')())
.process(html/*, options */)
.then(function(result) {
console.log(result.html);
// <div class="myComponent"><div class="myTitle">Super Title</div><div class="myText">Awesome Text</div></div>
});
Сomplex example
var posthtml = require('posthtml');
var html = '<html><body><p class="wow">OMG</p></body></html>';
posthtml([
require('posthtml-doctype')('<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">'),
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(function(result) {
console.log(result.html);
// <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
// <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>
});
singleTagsArray tags for extend default list single tags
Default: []
Options { singleTags: ['rect', 'custom'] }
...
<div>
...
<rect>
<custom>
</div>
closingSingleTagOption to specify version closing single tags.
Accepts values: default, slash, tag.
Default: default
Options { closingSingleTag: 'default' }
<singletag>
Options { closingSingleTag: 'slash' }
<singletag/>
Options { closingSingleTag: 'tag' }
<singletag></singletag>
input HTML
<a class="animals" href="#">
<span class="animals__cat" style="background: url(cat.png)">Cat</span>
</a>
Tree in PostHTML
[{
tag: 'a',
attrs: {
class: 'animals',
href: '#'
},
content: [{
tag: 'span',
attrs: {
class: 'animals__cat',
style: 'background: url(cat.png)'
},
content: ['Cat']
}]
}]
This is a simple function with a single argument
module.exports = function (tree) {
// do something for tree
tree.match({ tag: 'img' }, function(node) {
node = Object.assign(node, { attrs: { class: 'img-wrapped' } }});
return {
tag: 'span',
attrs: { class: 'img-wrapper' },
content: node
}
});
return tree;
}
Walk for all nodes in tree, run callback.
tree.walk(function(node) {
let classes = node.attrs && node.attrs.class.split(' ') || [];
if(classes.includes(className)) {
// do something for node
return node;
}
return node;
});
Find subtree in tree, run callback.
tree.match({ tag: 'custom-tag' }, function(node) {
// do something for node
var tag = node.tag;
node = Object.assign(node, { tag: 'div', attrs: { class: tag } }});
return node
});
For each found of class run callback
tree.matchClass('class-for-delete', function(node) {
// do something for node
return ''; // delete this node in tree
});
Something more? ;)
0.2.0 (2015-09-23)
options docs write in readme (d72c274)FAQs
HTML/XML processor
The npm package posthtml receives a total of 262,001 weekly downloads. As such, posthtml popularity was classified as popular.
We found that posthtml demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 2 open source maintainers collaborating on the project.
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