Can I use Goutte to scrape data from multiple pages in parallel?

Goutte is a PHP web scraping library that acts like a browser to make requests to websites and then allows you to navigate the DOM and extract the content you need. However, Goutte itself does not have built-in support for asynchronous or parallel requests that you would typically use to scrape multiple pages at the same time.

To scrape data from multiple pages in parallel while using Goutte, you would need to combine it with a tool that supports concurrency. One common approach is to use a multi-threading or multi-processing library in PHP, such as pthreads for threading (which is no longer maintained as of PHP 7.4) or pcntl for processes.

A popular way to handle concurrency in PHP for web scraping and other tasks is to use a library like ReactPHP or Amp. These libraries allow you to write asynchronous code using promises and event loops, which can handle multiple HTTP requests concurrently.

Here is an example of how you might use Amp with Goutte to scrape multiple pages in parallel:

<?php
require 'vendor/autoload.php';

use Goutte\Client;
use Amp\Loop;
use Amp\Promise;
use Amp\Http\Client\Pool\Http1Pool;
use Amp\Http\Client\Request;

// Create a Goutte client
$client = new Client();

// Use Amp's event loop to handle concurrency
Loop::run(function () use ($client) {
    // URLs to scrape
    $urls = [
        'http://example.com/page1',
        'http://example.com/page2',
        'http://example.com/page3',
        // ... more URLs
    ];

    // Create an array to hold promises
    $promises = [];

    // Create a new closure that performs the request and scraping
    $scrapePage = function ($url) use ($client) {
        return Amp\call(function () use ($client, $url) {
            // Perform the request with Goutte
            $crawler = $client->request('GET', $url);

            // Scrape the data you need
            $data = $crawler->filter('selector')->each(function ($node) {
                return $node->text();
            });

            return $data;
        });
    };

    // Loop through the URLs and add promises to the array
    foreach ($urls as $url) {
        $promises[] = $scrapePage($url);
    }

    // Wait for all promises to resolve
    $results = yield Promise\all($promises);

    // Handle the results
    foreach ($results as $result) {
        print_r($result);
    }
});

In this example, we define a list of URLs to scrape and then use Amp\call to create a coroutine for each URL, which runs the request and scraping logic. We collect the promises returned by these coroutines and then use Promise\all to wait for all of them to complete. Finally, we print out the results.

Keep in mind that when you're scraping websites, you should always respect the site's robots.txt file and their terms of service. Additionally, making too many requests in a short period of time can put a heavy load on the target server and might be considered abusive behavior. Always scrape responsibly and consider the impact on the target website.