SimpleXMLElement::__construct

(PHP 5 >= 5.0.1)

SimpleXMLElement::__construct Creates a new SimpleXMLElement object

Description

final public SimpleXMLElement::__construct ( string $data [, int $options = 0 [, bool $data_is_url = false [, string $ns = "" [, bool $is_prefix = false ]]]] )

Creates a new SimpleXMLElement object.

Parameters

data

A well-formed XML string or the path or URL to an XML document if data_is_url is TRUE.

options

Optionally used to specify additional Libxml parameters.

data_is_url

By default, data_is_url is FALSE. Use TRUE to specify that data is a path or URL to an XML document instead of string data.

ns

Namespace prefix or URI.

is_prefix

TRUE if ns is a prefix, FALSE if it's a URI; defaults to FALSE.

Return Values

Returns a SimpleXMLElement object representing data.

Errors/Exceptions

Produces an E_WARNING error message for each error found in the XML data and additionally throws an Exception if the XML data could not be parsed.

Tip

Use libxml_use_internal_errors() to suppress all XML errors, and libxml_get_errors() to iterate over them afterwards.

Examples

Note:

Listed examples may include example.php, which refers to the XML string found in the first example of the basic usage guide.

Example #1 Create a SimpleXMLElement object

<?php

include 'example.php';

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

?>

The above example will output:

PHP: Behind the Parser

Example #2 Create a SimpleXMLElement object from a URL

<?php

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

?>

Changelog

Version Description
5.2.0 Added the ns and is_prefix parameters.
5.1.2 Added the options and data_is_url parameters.

See Also

Коментарии

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.
2007-11-20 05:35:02
http://php5.kiev.ua/manual/ru/simplexmlelement.construct.html
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$optionstrue$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.
2009-08-16 21:52:58
http://php5.kiev.ua/manual/ru/simplexmlelement.construct.html
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();
}
?>
2011-03-23 00:50:21
http://php5.kiev.ua/manual/ru/simplexmlelement.construct.html
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.
2014-06-16 14:07:33
http://php5.kiev.ua/manual/ru/simplexmlelement.construct.html
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);
2016-06-08 00:36:56
http://php5.kiev.ua/manual/ru/simplexmlelement.construct.html
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>';

$sx0 = new SimpleXMLElement($xml0false);
$sx1 = new SimpleXMLElement($xml0false'http://example.com');
$sx2 = new SimpleXMLElement($xml0false'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
2017-04-22 18:23:01
http://php5.kiev.ua/manual/ru/simplexmlelement.construct.html
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)) {
           
$child parent::addChild($namenull$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;
    }
}
?>
2021-08-20 19:22:19
http://php5.kiev.ua/manual/ru/simplexmlelement.construct.html

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