registerXPathNamespace()

SimpleXMLElement::saveXML()

SimpleXML is a PHP extension that provides a simple and easy-to-use API for working with XML documents. The SimpleXMLElement::saveXML() method is one of the core functions provided by SimpleXML. It allows you to export an XML document represented by a SimpleXMLElement object as a string.

Understanding the SimpleXMLElement::saveXML() method

The SimpleXMLElement::saveXML() method exports an XML document. The syntax for modern PHP is as follows:

saveXML ( ?SimpleXMLElement $node = null, int $options = 0 ) : string|false

Here, $node is an optional parameter specifying a child node to export. If omitted, the entire document is exported. $options accepts bitwise flags from the LIBXML_* constants (e.g., LIBXML_NOEMPTYTAG) to control formatting and output behavior. The method returns the XML string on success, or false on failure. (Note: The nullable parameter syntax ?SimpleXMLElement requires PHP 7.1 or later.)

Example Usage

The following example demonstrates string output and saving to a file, along with basic error handling:

<?php

$xml = new SimpleXMLElement('<book><title>PHP Basics</title></book>');

// Return as a string
$xmlString = $xml->saveXML();
if ($xmlString !== false) {
    echo $xmlString;
}

// Save to a file
$xmlString = $xml->saveXML();
if ($xmlString !== false) {
    file_put_contents('output.xml', $xmlString);
    echo "XML saved successfully.";
} else {
    echo "Failed to save XML.";
}
?>

In the example above, we first create a SimpleXMLElement object representing an XML document with a book element containing a title child. We then call saveXML() without arguments to retrieve the XML as a string. Next, we pass that string to file_put_contents() to save the document directly to disk. The if checks ensure we handle potential false returns gracefully. (Note: Saving to a file requires write permissions for the target directory.)

Conclusion

The SimpleXMLElement::saveXML() method is an essential tool for working with XML in PHP. It provides a straightforward way to export XML data as a string using object-oriented syntax. By understanding its parameters and return values, developers can reliably manage XML documents in their applications.

Practice