无法使用PHP从我的XML获取带有XPATH的节点文本

Question

Hey everybody thanks for your time, I'm trying to parse a big XML file (pic bellow) and to get the text of specific nodes using XPATH expression in PHP.

Here is my php :

<?php
echo "[Generation Starts !]
";
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);

error_reporting(E_ALL);



if (file_exists('../source/particuliers/arborescence.xml')) {


$xml = new SimpleXMLElement(file_get_contents('../source/particuliers/arborescence.xml'));

$xml->registerXPathNamespace('dc', 'http://purl.org/dc/elements/1.1/');

$themes = $xml->xpath("/Arborescence/Item[@type='Theme']/Titre/text()");

var_dump($themes);





$JSON = json_encode($themes, JSON_UNESCAPED_UNICODE);

file_put_contents('testing.json', $JSON);

echo "[Generation Done !]
";

} else {

  echo "File wasn't found
";

}

I won't put the whole XML file here as it is way too big but here is a pic so you see the structure

Using this XPATH expression /Arborescence/Item[@type='Theme']/Titre/text() I expected to get text from my nodes but I only have an empty array with the right number of elements in it but all empty.

Anything I'm doing wrong ?

Answer 1

The result of SimpleXMLElement::xpath() is always an array of SimpleXMLElement objects (or false for an invalid expression). SimpleXMLElement object represent element nodes, but the extension does some magic for text nodes and attributes.

Stripping down the code from the question into an example:

$xml = <<<'XML'
<Arborescence>
  <Item type="Theme">
    <Titre>Loisirs</Titre>
  </Item>
</Arborescence>
XML;

$xml = new SimpleXMLElement($xml);
$themes = $xml->xpath("/Arborescence/Item[@type='Theme']/Titre/text()");

var_dump($themes);

Output:

array(1) { 
  [0]=> 
  object(SimpleXMLElement)#2 (1) { 
    [0]=> 
    string(7) "Loisirs"
  }
}

The result is an array with a single SimpleXMLElement that contains the text. You can use array_map() to cast all returned objects to strings.

$xml = new SimpleXMLElement($xml);
$themes = array_map(
    function(SimpleXMLElement $element) {
        return (string)$element;
    },
    $xml->xpath("/Arborescence/Item[@type='Theme']/Titre/text()")
);

Output:

array(1) {
  [0]=> 
  string(7) "Loisirs" 
}