gocrawlvspanther
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.
Panther is a convenient standalone library to scrape websites and to run end-to-end tests using real browsers.
Panther is super powerful. It leverages the W3C's WebDriver protocol to drive native web browsers such as Google Chrome and Firefox.
Panther is very easy to use, because it implements Symfony's popular BrowserKit and DomCrawler APIs, and contains all the features you need to test your apps. It will sound familiar if you have ever created a functional test for a Symfony app: as the API is exactly the same! Keep in mind that Panther can be used in every PHP project, as it is a standalone library.
Panther automatically finds your local installation of Chrome or Firefox and launches them, so you don't need to install anything else on your computer, a Selenium server is not needed!
In test mode, Panther automatically starts your application using the PHP built-in web-server. You can focus on writing your tests or web-scraping scenario and Panther will take care of everything else.
Features:
- executes the JavaScript code contained in webpages
- supports everything that Chrome (or Firefox) implements
- allows taking screenshots
- can wait for asynchronously loaded elements to show up
- lets you run your own JS code or XPath queries in the context of the loaded page
- supports custom Selenium server installations
- supports remote browser testing services including SauceLabs and BrowserStack
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
use Symfony\Component\Panther\Client;
require __DIR__.'/vendor/autoload.php'; // Composer's autoloader
$client = Client::createChromeClient();
// Or, if you care about the open web and prefer to use Firefox
$client = Client::createFirefoxClient();
$client->request('GET', 'https://api-platform.com'); // Yes, this website is 100% written in JavaScript
$client->clickLink('Get started');
// Wait for an element to be present in the DOM (even if hidden)
$crawler = $client->waitFor('#installing-the-framework');
// Alternatively, wait for an element to be visible
$crawler = $client->waitForVisibility('#installing-the-framework');
echo $crawler->filter('#installing-the-framework')->text();
$client->takeScreenshot('screen.png'); // Yeah, screenshot!