DomCrawler eases DOM navigation for HTML and XML documents.
If you are familiar with jQuery, DomCrawler is a PHP equivalent:
use Symfony\Component\DomCrawler\Crawler;
$crawler = new Crawler();
$crawler->addContent('<html><body><p>Hello World!</p></body></html>');
print $crawler->filterXPath('descendant-or-self::body/p')->text();
If you are also using the CssSelector component, you can use CSS Selectors instead of XPath expressions:
use Symfony\Component\DomCrawler\Crawler;
$crawler = new Crawler();
$crawler->addContent('<html><body><p>Hello World!</p></body></html>');
print $crawler->filter('body > p')->text();
You can run the unit tests with the following command:
$ cd path/to/Symfony/Component/DomCrawler/
$ composer.phar install
$ phpunit