node-crawlervsspidr
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
Spidr is a Ruby gem that provides a simple and flexible way to spider and scrape websites. It allows you to easily navigate through a website, following links and scraping data as you go. 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 Spidr is its ability to spider a website, following all the links on a page and visiting all the pages of a website. This allows you to easily and quickly scrape large amounts of data from a website, without having to manually specify which pages to visit.
In addition to its spidering capabilities, Spidr also provides a variety of other features that can simplify the web scraping process. It can automatically filter which links to follow and which pages to visit, it can handle cookies and authentication, and it can automatically store the scraped data in a database or file. 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 'spidr'
Spidr.start_at("http://example.com") do |spider|
spider.every_page do |page|
puts "Visiting: #{page.url}"
# Extract data from the page using Nokogiri
doc = Nokogiri::HTML(page.body)
title = doc.css("title").text
puts "Title: #{title}"
end
end