repository·master·Indexed 26 days ago
https://github.com/inikulin/parse5A high-performance, WHATWG HTML Living Standard compliant HTML parsing and serialization toolset for Node.js. Designed to mimic browser-level parsing behavior, it includes the core parser and serializer as well as specialized packages: parse5-html-rewriting-stream for streaming transformations, parse5-htmlparser2-tree-adapter for htmlparser2 compatibility, parse5-parser-stream for streaming parsing with scripting support, parse5-plain-text-conversion-stream for converting plain text to HTML, and parse5-sax-parser for event-based parsing.
parse5-plain-text-conversion-stream package provides a stream implementation that converts plain text into an HTML document as required by the HTML specification.The parse5 ecosystem consists of several specialized packages depending on your requirements for parsing, streaming, or rewriting HTML:
htmlparser2 tree structures with parse5.To use the streaming SAX-style HTML parser, install the parse5-sax-parser package using npm.
npm install --save parse5-sax-parserTo use the streaming HTML parser with scripting support in your project, install the parse5-parser-stream package using npm.
npm install --save parse5-parser-streamInstall the parse5-html-rewriting-stream package via npm to use the streaming HTML rewriter.
npm install --save parse5-html-rewriting-streamInstall the parse5-plain-text-conversion-stream package via npm to use a stream that converts plain text into an HTML document according to the HTML specification.
npm install --save parse5-plain-text-conversion-streamInstall the parse5-htmlparser2-tree-adapter package via npm to use the htmlparser2 tree adapter with parse5.
npm install --save parse5-htmlparser2-tree-adapterTo use the parse5 HTML parser and serializer in your project, install it using npm:
npm install --save parse5The parser implements the HTML 'Adoption Agency' algorithm. This algorithm is triggered when a formatting element (like <b> or <i>) is encountered while an existing formatting element of the same type is already in scope.
When this occurs, the parser:
Developers using the parser can rely on this built-in behavior to ensure that malformed or highly nested formatting tags are parsed exactly as a web browser would handle them.
The RewritingStream class is a Node.js Transform stream that allows you to perform SAX-style HTML rewriting. It parses HTML and emits events for different token types, allowing you to intercept and modify them before pushing the results to the output stream. Because it is a Transform stream, you can pipe data through it (e.g., from an HTTP response to a file).
To rewrite HTML, listen for events like startTag, endTag, or text, modify the token if necessary, and then call the corresponding emit* method to write the modified (or original) content to the stream.
const RewritingStream = require('parse5-html-rewriting-stream');
const http = require('http');
const fs = require('fs');
const file = fs.createWriteStream('/home/google.com.html');
const rewriter = new RewritingStream();
// Replace divs with spans
rewriter.on('startTag', startTag => {
if (startTag.tagName === 'span') {
startTag.tagName = 'div';
}
rewriter.emitStartTag(startTag);
});
rewriter.on('endTag', endTag => {
if (endTag.tagName === 'span') {
endTag.tagName = 'div';
}
rewriter.emitEndTag(endTag);
});
// Wrap all text nodes with an <i> tag
rewriter.on('text', (_, raw) => {
// Use the raw representation of text without HTML entities decoding
rewriter.emitRaw(`<i>${raw}</i>`);
});
http.get('http://google.com', res => {
// Assumes response is UTF-8.
res.setEncoding('utf8');
// `RewritingStream` is a `Transform` stream, which means you can pipe
// through it.
res.pipe(rewriter).pipe(file);
});