gocrawlvscrwlr-crawler
Gocrawl is a polite, slim and concurrent web crawler library written in Go. It is designed to be simple and easy to use, while still providing a high degree of flexibility and control over the crawling process.
One of the key features of Gocrawl is its politeness, which means that it obeys the website's robots.txt file and respects the crawl-delay specified in the file. It also takes into account the website's last modified date, if any, to avoid recrawling the same page. This helps to reduce the load on the website and prevent any potential legal issues. Gocrawl is also highly concurrent, which allows it to efficiently crawl large numbers of pages in parallel. This helps to speed up the crawling process and reduce the time required to complete the task.
The library also offers a high degree of flexibility in customizing the crawling process. It allows you to specify custom callbacks and handlers for handling different types of pages, such as error pages, redirects, and so on. This allows you to handle and process the pages as per your requirement. Additionally, Gocrawl provides various functionalities such as support for cookies, user-agent, auto-detection of links, and auto-detection of sitemaps.
This library provides kind of a framework and a lot of ready to use, so-called steps, that you can use as building blocks, to build your own crawlers and scrapers with.
Some features: - Crawler Politeness innocent (respecting robots.txt, throttling,...) - Load URLs using - a (PSR-18) HTTP client (default is of course Guzzle) - or a headless browser (chrome) to get source after Javascript execution - Get absolute links from HTML documents link - Get sitemaps from robots.txt and get all URLs from those sitemaps - Crawl (load) all pages of a website spider - Use cookies (or don't) cookie - Use any HTTP methods (GET, POST,...) and send any headers or body - Iterate over paginated list pages repeat - Extract data from: - HTML and also XML (using CSS selectors or XPath queries) - JSON (using dot notation) - CSV (map columns) - Extract schema.org structured data in JSON-LD format from HTML documents - Keep memory usage low by using PHP Generators muscle - Cache HTTP responses during development, so you don't have to load pages again and again after every code change - Get logs about what your crawler is doing (accepts any PSR-3 LoggerInterface)
Example Use
// Only enqueue the root and paths beginning with an "a"
var rxOk = regexp.MustCompile(`http://duckduckgo\.com(/a.*)?$`)
// Create the Extender implementation, based on the gocrawl-provided DefaultExtender,
// because we don't want/need to override all methods.
type ExampleExtender struct {
gocrawl.DefaultExtender // Will use the default implementation of all but Visit and Filter
}
// Override Visit for our need.
func (x *ExampleExtender) Visit(ctx *gocrawl.URLContext, res *http.Response, doc *goquery.Document) (interface{}, bool) {
// Use the goquery document or res.Body to manipulate the data
// ...
// Return nil and true - let gocrawl find the links
return nil, true
}
// Override Filter for our need.
func (x *ExampleExtender) Filter(ctx *gocrawl.URLContext, isVisited bool) bool {
return !isVisited && rxOk.MatchString(ctx.NormalizedURL().String())
}
func ExampleCrawl() {
// Set custom options
opts := gocrawl.NewOptions(new(ExampleExtender))
// should always set your robot name so that it looks for the most
// specific rules possible in robots.txt.
opts.RobotUserAgent = "Example"
// and reflect that in the user-agent string used to make requests,
// ideally with a link so site owners can contact you if there's an issue
opts.UserAgent = "Mozilla/5.0 (compatible; Example/1.0; +http://example.com)"
opts.CrawlDelay = 1 * time.Second
opts.LogFlags = gocrawl.LogAll
// Play nice with ddgo when running the test!
opts.MaxVisits = 2
// Create crawler and start at root of duckduckgo
c := gocrawl.NewCrawlerWithOptions(opts)
c.Run("https://duckduckgo.com/")
// Remove "x" before Output: to activate the example (will run on go test)
// xOutput: voluntarily fail to see log output
}
<?php
require_once 'vendor/autoload.php';
use Crwlr\Crawler;
$crawler = new Crawler();
$crawler->get('https://example.com', ['User-Agent' => 'webscraping.fyi']);
// more links can be followed:
$crawler->followLinks();
// and current page can be parsed:
$response = $crawler->response();
$title = $crawler->filter('title')->text();
echo $response->getContent();