simplexml and xpath, read sibling

Question

I have the following XML file :

    
        [...]
             


        

Answer 1

$xpath = './/wp:meta_key[text()="_yoast_wpseo_title"]/following-sibling::wp:meta_value[1]/text()';
$items = $xml->channel->item;
foreach( $items as $item ) {
  $result = $item->xpath($xpath);
  print "$result[0]\n";
}

// => item-1-title
// => item-2-title

Explanation of the XPath expression:

.                               - from the current node...
//wp:meta_key                   - get all descendant wp:meta_key nodes
[text()="_yoast_wpseo_title"]   - whose text content is _yoast_wpseo_title
/following-sibling::            - then get the siblings that come after this
wp:meta_value[1]                - with tag wp:meta_value; only take the first
/text()                         - and read its text

Answer 2

This solution includes reference to the Wordpress XML namespace:

$doc = new SimpleXmlElement($xml);
$doc->registerXPathNamespace ('wp', 'http://wordpress.org/export/1.0/');

$wp_meta_title = $doc->xpath("//wp:postmeta[wp:meta_key = '_yoast_wpseo_title']/wp:meta_value");

foreach ($wp_meta_title as $title) {
    echo (string)$title . "\n";
}

result:

item-1-title
item-2-title

See http://ideone.com/qjOfIW

The path //wp:postmeta[wp:meta_key = '_yoast_wpseo_title']/wp:meta_value is pretty straight-forward, I don't think it needs special explanation.