SimpleXMLElement::asXML

(PHP 5, PHP 7, PHP 8)

SimpleXMLElement::asXML — Return a well-formed XML string based on SimpleXML element

Description

public SimpleXMLElement::asXML(?string $filename = null): string|bool

The asXML method formats the parent object's data in XML version 1.0.

Parameters

filename: If a string value is provided, the function writes the data to the file rather than returning it.

Return Values

If the filename isn't specified, this function returns a string on success and false on error. If the parameter is specified, it returns true if the file was written successfully and false otherwise.

Changelog

Version	Description
8.0.0	`filename` is nullable now.

Examples

Example #1 Get XML

<?php
$string = <<<XML
<a>
 <b>
  <c>text</c>
  <c>stuff</c>
 </b>
 <d>
  <c>code</c>
 </d>
</a>
XML;

$xml = new SimpleXMLElement($string);

echo $xml->asXML();

?>

The above example will output:

<?xml version="1.0"?>
<a>
 <b>
  <c>text</c>
  <c>stuff</c>
 </b>
 <d>
  <c>code</c>
 </d>
</a>

asXML also works on Xpath results:

Example #2 Using asXML() on SimpleXMLElement::xpath() results

<?php
// Continued from example XML above.

/* Search for <a><b><c> */
$result = $xml->xpath('/a/b/c');

foreach ($result as $node) {
    echo $node->asXML();
}
?>

The above example will output:

<c>text</c><c>stuff</c>

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User Contributed Notes 2 notes

down

andreas dot theissen at t-online dot de ¶

11 years ago

To prevent asXML from encoding vowels unwantedly, simply use an approriate XML header with encoding in advance.

If you do so, asXML will happily leave your vowels (and the header) entirely untouched.

<?php

$xmlstr =
'<?xml version="1.0" encoding="UTF-8"?>
<keys>
  <key lang="en">&lt;Insert&gt;</key>
  <key lang="de">&lt;Einfügen&gt;</key>
</keys>';

$sxe = new SimpleXMLElement($xmlstr);

$output = $sxe->asXML();

?>

$xmlstr and $output are identical now.

The subsequent use of html_entity_decode() (as proposed in the very beginning in another post) has several drawbacks:

1. It is slow
2. It is expensive
3. If there are already encoded arrow brackets or double quotes in your source for instance (as shown in the above example), markup will be broken.