ConFoo 2025

SimpleXMLElement::__construct

(PHP 5, PHP 7, PHP 8)

SimpleXMLElement::__construct Crée un nouvel objet SimpleXMLElement

Description

public SimpleXMLElement::__construct(
    string $data,
    int $options = 0,
    bool $dataIsURL = false,
    string $namespaceOrPrefix = "",
    bool $isPrefix = false
)

Crée un nouvel objet SimpleXMLElement.

Liste de paramètres

data

Une chaîne de caractères XML bien formée ou le chemin d'accès ou un URL pointant à un document XML si dataIsURL vaut true.

options

Optionnellement utilisé pour spécifier des paramètres Libxml additionnels, qui affecte la lecture de documents XML. Les options affectant la sortie des documents XML (par exemple LIBXML_NOEMPTYTAG) sont ignorée silencieusement.

Note:

Il peut être nécessaire de passer LIBXML_PARSEHUGE pour pouvoir traiter des nœuds de texte profondément imbriqués ou très volumineux.

dataIsURL

Par défaut, dataIsURL vaut false. Utilisez true pour spécifier que le paramètre data est un chemin d'accès ou un URL pointant à un document XML au lieu d'une chaîne de caractères de données.

namespaceOrPrefix

Préfixe d'espace de noms ou URI.

isPrefix

true si namespaceOrPrefix est un préfix, false sinon. Valeur par défaut : false.

Erreurs / Exceptions

Produit un message d'erreur de type E_WARNING pour chaque erreur trouvée dans les données XML et lance également une exception si les données XML ne peuvent être analysées.

Astuce

Utilisez la fonction libxml_use_internal_errors() pour supprimer toutes les erreurs XML et la fonction libxml_get_errors() pour les parcourir.

Exemples

Note:

Les exemples listés incluent parfois example.php, ceci fait référence à la chaine XML du premier exemple de l'utilisation de base.

Exemple #1 Crée un objet SimpleXMLElement

<?php

include 'example.php';

$sxe = new SimpleXMLElement($xmlstr);
echo
$sxe->movie[0]->title;

?>

L'exemple ci-dessus va afficher :

PHP: Behind the Parser

Exemple #2 Crée un objet SimpleXMLElement à partir d'un URL

<?php

$sxe
= new SimpleXMLElement('http://example.org/document.xml', 0, true);
echo
$sxe->asXML();

?>

Voir aussi

add a note

User Contributed Notes 7 notes

up
9
rowan dot collins at gmail dot com
7 years ago
The manual doesn't really explain what the $ns argument (and the accompanying $is_prefix) are for.

What they do is similar to the ->children() method: they set the context of the returned object to that namespace, so that access via ->elementName and ['attributeName'] refer to elements and attributes in that namespace.

In particular, they do *not* change the namespaces which exist on the document.

See this example:

<?php
// This XML contains two elements called <child>
// One is in the namespace http://example.com, with local prefix 'ws'
// The other has no namespace (no prefix, and no default namespace declared)
$xml = '<ws:example xmlns:ws="http://example.com"><child>Not in namespace</child><ws:child>In example namespace</ws:child></ws:example>';

$sx0 = new SimpleXMLElement($xml, 0, false);
$sx1 = new SimpleXMLElement($xml, 0, false, 'http://example.com');
$sx2 = new SimpleXMLElement($xml, 0, false, 'ws', true);

echo
"
Without:
{$sx0->child}
By namespace:
{$sx1->child}
By prefix:
{$sx2->child}
"
;
?>

Output:

Without: Not in namespace
By namespace: In example namespace
By prefix: In example namespace
up
9
tudor at culise dot net
17 years ago
This class is extendable, but it's too bad that its constructor cannot be overriden (PHP says it's a final method). Thus the class should be wrapped using the delegation principle rather that extended.
up
6
ahmad dot mayahi at gmail dot com
8 years ago
You won't be able to load an XML file without root element:

//This will throw an exception
$xml = new SimpleXMLElement('<?xml version="1.0" encoding="UTF-8"?>', null, false);

//Here is the solution
$xml = new SimpleXMLElement('<?xml version="1.0" encoding="UTF-8"?><root></root>', null, false);
up
4
info at ensostudio dot ru
3 years ago
Extended SimpleXMLElement:
<?php
class XmlElement extends \SimpleXMLElement
{
public static function
factory(string $root): self
{
return new static(
'<?xml version="1.0" encoding="UTF-8"?><'.$root.'/>', LIBXML_BIGLINES | LIBXML_COMPACT);
}

/**
* @param iterable $attributes An array of element attributes as name/value pairs
* @return $this
*/
public function addAttributes(iterable $attributes)
{
foreach (
$attributes as $name => $value) {
$this->addAttribute($name, $value);
}

return
$this;
}

/**
* @param string $name The sub-element name
* @param string|array|null $valueOrAttributes The sub-element value or an array of attributes
* @param string|null $namespace The sub-element namespace
* @return static|null
*/
public function addChild($name, $valueOrAttributes = null, $namespace = null)
{
if (
is_array($valueOrAttributes)) {
$child = parent::addChild($name, null, $namespace);
foreach (
$valueOrAttributes as $name => $value) {
$child->addAttribute($name, $value);
}
} else {
$child = parent::addChild($name, $valueOrAttributes, $namespace);
}

return
$child;
}

/**
* @param iterable $childs An array of sub-elements as name/value(or attributes) pairs
* @return $this
*/
public function addChilds(iterable $childs)
{
foreach (
$childs as $name => $value) {
$this->addChild($name, $value);
}

return
$this;
}
}
?>
up
4
bertolini dot cedric at me dot com
10 years ago
It's worth noting that the behavior of SimpleXmlElement::__construct is not exactly the same as simplexml_load_string, regarding libxml_use_internal_errors().

In my case,

<?php
libxml_use_internal_errors
(true);
new
\SimpleXmlElement($data);
?>

was still throwing error. But as soon as I switched to

<?php
libxml_use_internal_errors
(true);
simplexml_load_string($data);
?>

everything worked fine and I stopped getting an error.
up
5
kumarldh at gmail dot com
13 years ago
Using libxml_use_internal_errors() may suppress errors but Exception still requires decent handling. I used following code snippet.

<?php
libxml_use_internal_errors
(true);
try{
$xmlToObject = new SimpleXMLElement($notSoWellFormedXML);
} catch (
Exception $e){
echo
'Please try again later...';
exit();
}
?>
up
0
uramihsayibok, gmail, com
15 years ago
As I was filling out a bug report, I realized why (speculation here) the constructor is final: so that functions like simplexml_load_file and simplexml_load_string can work. I imagine the PHP-ized code looks something like

<?php

function simplexml_load_file($filename, $class_name = "SimpleXMLElement", $options = 0, $ns = "", $is_prefix = false) {
return new
$class_name($filename, $options, true, $ns, $is_prefix);
}

?>

If we were to use a different $class_name and change the constructor's definition these functions wouldn't work.

There's no easy, sensible solution that keeps simplexml_load_file and simplexml_load_string.
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