Security News
Combatting Alert Fatigue by Prioritizing Malicious Intent
In 2023, data breaches surged 78% from zero-day and supply chain attacks, but developers are still buried under alerts that are unable to prevent these threats.
posthtml-parser
Advanced tools
The posthtml-parser npm package is a tool used to parse HTML into an Abstract Syntax Tree (AST). This allows developers to manipulate HTML content programmatically, making it easier to perform tasks such as transforming HTML structures, extracting specific elements, and integrating with other tools in the PostHTML ecosystem.
Parsing HTML to AST
This feature allows you to parse a string of HTML into an Abstract Syntax Tree (AST). The AST can then be manipulated programmatically.
const parse = require('posthtml-parser');
const html = '<div class="example">Hello World</div>';
const ast = parse(html);
console.log(ast);
Handling HTML fragments
This feature allows you to parse HTML fragments and control parsing options such as whether to convert tag names to lowercase.
const parse = require('posthtml-parser');
const fragment = '<span>Fragment</span>';
const ast = parse(fragment, { lowerCaseTags: false });
console.log(ast);
Integration with PostHTML plugins
This feature demonstrates how to integrate the parser with PostHTML plugins to transform HTML content. In this example, a plugin is used to change all <div> tags to <section> tags.
const posthtml = require('posthtml');
const parse = require('posthtml-parser');
const html = '<div class="example">Hello World</div>';
posthtml()
.use(tree => {
tree.match({ tag: 'div' }, node => {
node.tag = 'section';
return node;
});
})
.process(html)
.then(result => console.log(result.html));
htmlparser2 is a fast and forgiving HTML/XML parser. It is similar to posthtml-parser in that it parses HTML into a tree structure, but it is more focused on speed and flexibility. It also supports streaming and can handle large documents efficiently.
parse5 is a highly compliant HTML parser that closely follows the WHATWG HTML specification. It is similar to posthtml-parser in its ability to parse HTML into an AST, but it is known for its strict adherence to web standards and comprehensive support for HTML5 features.
cheerio is a fast, flexible, and lean implementation of core jQuery designed specifically for the server. It parses HTML and XML into a DOM-like structure, allowing for jQuery-like manipulation of the document. While it offers similar parsing capabilities, it is more focused on providing a familiar API for DOM manipulation.
Parse HTML/XML to PostHTML AST. More about PostHTML
NPM install
$ npm install posthtml-parser
<a class="animals" href="#">
<span class="animals__cat" style="background: url(cat.png)">Cat</span>
</a>
const parser = require('posthtml-parser')
const fs = require('fs')
const html = fs.readFileSync('path/to/input.html').toString()
console.log(parser(html)) // Logs a PostHTML AST
<a class="animals" href="#">
<span class="animals__cat" style="background: url(cat.png)">Cat</span>
</a>
[{
tag: 'a',
attrs: {
class: 'animals',
href: '#'
},
content: [
'\n ',
{
tag: 'span',
attrs: {
class: 'animals__cat',
style: 'background: url(cat.png)'
},
content: ['Cat']
},
'\n'
]
}]
Any parser being used with PostHTML should return a standard PostHTML Abstract Syntax Tree (AST). Fortunately, this is a very easy format to produce and understand. The AST is an array that can contain strings and objects. Any strings represent plain text content to be written to the output. Any objects represent HTML tags.
Tag objects generally look something like this:
{
tag: 'div',
attrs: {
class: 'foo'
},
content: ['hello world!']
}
Tag objects can contain three keys. The tag
key takes the name of the tag as the value. This can include custom tags. The optional attrs
key takes an object with key/value pairs representing the attributes of the html tag. A boolean attribute has an empty string as its value. Finally, the optional content
key takes an array as its value, which is a PostHTML AST. In this manner, the AST is a tree that should be walked recursively.
FAQs
Parse HTML/XML to PostHTMLTree
The npm package posthtml-parser receives a total of 605,151 weekly downloads. As such, posthtml-parser popularity was classified as popular.
We found that posthtml-parser demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 3 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
In 2023, data breaches surged 78% from zero-day and supply chain attacks, but developers are still buried under alerts that are unable to prevent these threats.
Security News
Solo open source maintainers face burnout and security challenges, with 60% unpaid and 60% considering quitting.
Security News
License exceptions modify the terms of open source licenses, impacting how software can be used, modified, and distributed. Developers should be aware of the legal implications of these exceptions.