Requisito previo: Leer conceptos básicos de XML
La función SimpleXMLElement::xpath() es una función incorporada en PHP que ejecuta la consulta XPath en el documento XML.
Sintaxis:
SimpleXMLElement::xpath( $path )
Parámetros: esta función acepta un único parámetro $ruta que se requiere. Se utiliza para especificar la ruta XPath del documento XML.
Valor de retorno: Devuelve una array de SimpleXMLElements en caso de éxito o False en caso de error.
Nota: Esta función está disponible en PHP 5.2.0 y versiones posteriores.
Ejemplo:
<?php
// Loading XML document to $user
$user = <<<XML
<user>
<id>12345</id>
<username>Geeks123</username>
<name>GeeksforGeeks</name>
<phone>+91-XXXXXXXXXX</phone>
<detail font-color="blue" font-size="24px">
Noida India
</detail>
</user>
XML;
// Loading string as simple xml object
$xml = simplexml_load_string($user);
// Retrieving xpaths
$result = $xml->xpath("username");
// Printing output
print_r($result);
?>
Producción:
Array
(
[0] => SimpleXMLElement Object
(
[0] => Geeks123
)
)
Ejemplo 2:
<?php
// Loading XML document to $user
$user = <<<XML
<user xmlns:user_id="http://geeksforgeeks.org/user">
<single_user id="1">
<user_id:id>12345</user_id:id>
<username>Geeks123</username>
<name>GeeksforGeeks</name>
<phone>+91-XXXXXXXXXX</phone>
<detail font-color="blue" font-size="24px">
Noida India
</detail>
</single_user>
<single_user id="2">
<user_id:id>15980</user_id:id>
<username>Geeks54321</username>
<name>Geeks</name>
<phone>+91-XXXXXXXXXX</phone>
<detail font-color="blue" font-size="24px">
Noida India
</detail>
</single_user>
</user>
XML;
// Loading string as simple xml object
$xml = simplexml_load_string($user);
// Registering xpath namespace
$xml->registerXPathNamespace('u', 'http://geeksforgeeks.org/user');
// Retrieving xpaths
$result = $xml->xpath('//u:id');
// Printing output
foreach ($result as $id) {
echo $id . "<br>";
}
?>
Producción:
12345
15980
Ejemplo 3:
<?php
// Loading XML document to $user
$user = <<<XML
<user xmlns:user_id="http://geeksforgeeks.org/user">
<single_user id="1" xmlns:name="http://geeksforgeeks.org/user/name">
<user_id:id>12345</user_id:id>
<username>rakesh123</username>
<name:firstname>Rakesh</name:firstname>
<name:lastname>Kumar</name:lastname>
<phone>+91-XXXXXXXXXX</phone>
<detail>Noida India</detail>
</single_user>
<single_user id="2" xmlns:name="http://geeksforgeeks.org/user/name">
<user_id:id>57833</user_id:id>
<username>man123</username>
<name:firstname>Manjeet</name:firstname>
<name:lastname>Singh</name:lastname>
<phone>+91-XXXXXXXXXX</phone>
<detail>Kolkata, India</detail>
</single_user>
<single_user id="3" xmlns:name="http://geeksforgeeks.org/user/name">
<user_id:id>98944</user_id:id>
<username>ak98</username>
<name:firstname>Ak</name:firstname>
<name:lastname>Singh</name:lastname>
<phone>+91-XXXXXXXXXX</phone>
<detail>Noida India</detail>
</single_user>
</user>
XML;
// Loading string as simple xml object
$xml = simplexml_load_string($user);
// Registering xpath namespace
$xml->registerXPathNamespace('u', 'http://geeksforgeeks.org/user');
$xml->registerXPathNamespace('un', 'http://geeksforgeeks.org/user/name');
// Retrieving xpaths
$result = $xml->xpath('//u:id');
$result_f_name = $xml->xpath('//un:firstname');
$result_l_name = $xml->xpath('//un:lastname');
// Printing output
foreach ($result as $id) {
echo $id . "<br>";
}
foreach ($result_f_name as $f_name) {
echo $f_name . "<br>";
}
foreach ($result_l_name as $l_name) {
echo $l_name . "<br>";
}
?>
Producción:
12345
57833
98944
Rakesh
Manjeet
Ak
Kumar
Singh
Singh
Referencia: https://www.php.net/manual/en/simplexmlelement.xpath.php