How to use this function to grab a div - php

Question

I found this function in snipplr which grabs ra div with certain attribute. I tried to use it, but it didn't work. Is there a something wrong in my way of using it?
http://snipplr.com/view.php?codeview&id=20987
function get_tag( $attr, $value, $xml, $tag=null ) {
if( is_null($tag) )
$tag = '\w+';
else
$tag = preg_quote($tag);
$attr = preg_quote($attr);
$value = preg_quote($value);
$tag_regex = "/<(".$tag.")[^>]*$attr\s*=\s*".
"(['\"])$value\\2[^>]*>(.*?)<\/\\1>/"
preg_match_all($tag_regex,
$xml,
$matches,
PREG_PATTERN_ORDER);
return $matches[3];
}
I made a change on it to use it for a url like this:
function get_tag( $attr, $value, $page, $tag=null ) {
if( is_null($tag) )
$tag = '\w+';
else
$tag = preg_quote($tag);
$attr = preg_quote($attr);
$value = preg_quote($value);
$tag_regex = "/<(".$tag.")[^>]*$attr\s*=\s*".
"(['\"])$value\\2[^>]*>(.*?)<\/\\1>/";
$page = file_get_contents($page);
preg_match_all($tag_regex,
$page,
$matches,
PREG_PATTERN_ORDER);
return $matches[3];
}
get_tag("class","weather","http://www.masrawy.com","div");
How can I use this correctly?

Answer 1

Dont use a regex for this. Use something that can parse and query the DOM like DOMDocument, Zend_Dom_Query or SimpleHTMLDOM.
DOMDocument example:
$dom = new DomDocument();
$html = file_get_contents('http://www.masrawy.com');
$dom->loadHTML($html);
$finder = new DomXPath($dom);
$classname="weather";
$nodes = $finder->query("//div[contains(concat(' ', normalize-space(#class), ' '), ' $classname ')]");
$extracted = array();
foreach($nodes as $element)
{
// convert to html string
$extracted[] = $element->ownerDocument->saveXML($element);
}
// now iterate over extracted and output...
An Zend_Dom_Query example:
$html = file_get_contents("http://www.masrawy.com");
$dom = new Zend_Dom_Query($html);
$results = $dom->query('div.theCssClassName');
$extracted = array();
foreach($results as $element)
{
// convert to html string
$extracted[] = $element->ownerDocument->saveXML($element);
}
// now iterate over extracted and output...