node-crawlervswombat
node-crawler is a popular web scraping library for Node.js that allows you to easily navigate and extract data from websites. It has a simple API and supports concurrency, making it efficient for scraping large numbers of pages.
Features:
- Server-side DOM & automatic jQuery insertion with Cheerio (default) or JSDOM,
- Configurable pool size and retries,
- Control rate limit,
- Priority queue of requests,
- forceUTF8 mode to let crawler deal for you with charset detection and conversion,
- Compatible with 4.x or newer version.
- Http2 support
- Proxy support
Wombat is a Ruby gem that makes it easy to scrape websites and extract structured data from HTML pages. It is built on top of Nokogiri, a popular Ruby gem for parsing and searching HTML and XML documents, and it provides a simple and intuitive API for defining and running web scraping operations.
One of the main features of Wombat is its ability to extract structured data from HTML pages using a simple, CSS-like syntax. It allows you to define a set of rules for extracting data from a page, and then automatically applies those rules to the page's HTML to extract the desired data. This makes it easy to extract data from even complex and dynamic pages, without having to write a lot of custom code.
In addition to its data extraction capabilities, Wombat also provides a variety of other features that can simplify the web scraping process. It can automatically follow links and scrape multiple pages, it can handle pagination and AJAX requests, and it can handle cookies and authentication. It also provides a built-in support for parallelism and queueing to speed up the scraping process.
Example Use
const Crawler = require('crawler');
const c = new Crawler({
maxConnections: 10,
// This will be called for each crawled page
callback: (error, res, done) => {
if (error) {
console.log(error);
} else {
const $ = res.$;
// $ is Cheerio by default
//a lean implementation of core jQuery designed specifically for the server
console.log($('title').text());
}
done();
}
});
// Queue just one URL, with default callback
c.queue('http://www.amazon.com');
// Queue a list of URLs
c.queue(['http://www.google.com/','http://www.yahoo.com']);
// Queue URLs with custom callbacks & parameters
c.queue([{
uri: 'http://parishackers.org/',
jQuery: false,
// The global callback won't be called
callback: (error, res, done) => {
if (error) {
console.log(error);
} else {
console.log('Grabbed', res.body.length, 'bytes');
}
done();
}
}]);
// Queue some HTML code directly without grabbing (mostly for tests)
c.queue([{
html: '<p>This is a <strong>test</strong></p>'
}]);
require 'wombat'
Wombat.crawl do
base_url "https://www.github.com"
path "/"
headline xpath: "//h1"
subheading css: "p.alt-lead"
what_is({ css: ".one-fourth h4" }, :list)
links do
explore xpath: '/html/body/header/div/div/nav[1]/a[4]' do |e|
e.gsub(/Explore/, "Love")
end
features css: '.nav-item-opensource'
business css: '.nav-item-business'
end
end
{
"headline"=>"How people build software",
"subheading"=>"Millions of developers use GitHub to build personal projects, support their businesses, and work together on open source technologies.",
"what_is"=>[
"For everything you build",
"A better way to work",
"Millions of projects",
"One platform, from start to finish"
],
"links"=>{
"explore"=>"Love",
"features"=>"Open source",
"business"=>"Business"
}
}