Extract DOM-elements from string, in PHP

user635443 picture user635443 · Feb 26, 2011 · Viewed 37.7k times · Source

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I have one string-variable in my php-script, that contains html-page. How i can extract DOM-elements from this string?

For example, in this string '<div class="someclass">text</div>', i wish get variable 'text'. How i can do this?

Answer

Pascal MARTIN picture Pascal MARTIN · Feb 26, 2011

You need to use the DOMDocument class, and, more specifically, its loadHTML method, to load your HTML string to a DOM object.

For example :

$string = <<<HTML
<p>test</p>
<div class="someclass">text</div>
<p>another</p>
HTML;

$dom = new DOMDocument();
$dom->loadHTML($string);


After that, you'll be able to manipulate the DOM, using for instance the DOMXPath class to do XPath queries on it.

For example, in your case, you could use something based on this portion of code :

$xpath = new DOMXpath($dom);
$result = $xpath->query('//div[@class="someclass"]');
if ($result->length > 0) {
    var_dump($result->item(0)->nodeValue);
}

Which, here, would get you the following output :

string 'text' (length=4)


As an alternative, instead of DOMDocument, you could also use simplexml_load_string and SimpleXMLElement::xpath -- but for complex manipulations, I generally prefer using DOMDocument.