example_simple.php

<?php

use Example\StatsHandler;
use VDB\Spider\Discoverer\XPathExpressionDiscoverer;
use Symfony\Contracts\EventDispatcher\Event;
use VDB\Spider\Event\SpiderEvents;
use VDB\Spider\Spider;

require_once('example_complex_bootstrap.php');

// Create Spider
$seed = 'https://www.dmoz-odp.org/';
$spider = new Spider($seed);

// Add a URI discoverer. Without it, the spider does nothing. In this case, we want <a> tags from a certain <div>
$spider->getDiscovererSet()->set(new XPathExpressionDiscoverer("//div[@id='catalogs']//a"));

// Set some sane options for this example. In this case, we only get the first 10 items from the start page.
$spider->getDiscovererSet()->maxDepth = 1;
$spider->getQueueManager()->maxQueueSize = 10;

// Let's add something to enable us to stop the script
$spider->getDispatcher()->addListener(
    SpiderEvents::SPIDER_CRAWL_USER_STOPPED,
    function (Event $event) {
        echo "\nCrawl aborted by user.\n";
        exit();
    }
);

// Add a listener to collect stats to the Spider and the QueueMananger.
// There are more components that dispatch events you can use.
$statsHandler = new StatsHandler();
$spider->getQueueManager()->getDispatcher()->addSubscriber($statsHandler);
$spider->getDispatcher()->addSubscriber($statsHandler);

// Execute crawl
$spider->crawl();

// Build a report
echo "\n  ENQUEUED:  " . count($statsHandler->getQueued());
echo "\n  SKIPPED:   " . count($statsHandler->getFiltered());
echo "\n  FAILED:    " . count($statsHandler->getFailed());
echo "\n  PERSISTED:    " . count($statsHandler->getPersisted());

// Finally we could do some processing on the downloaded resources
// In this example, we will echo the title of all resources
echo "\n\nDOWNLOADED RESOURCES: ";
foreach ($spider->getDownloader()->getPersistenceHandler() as $resource) {
    echo "\n - " . $resource->getCrawler()->filterXpath('//title')->text();
}