README

About

Handy utility functions to query XML. Was initially written to simplify dealing with raw SOAP responses, but can also be useful in general, enabling a more functinal style of extracting data from XML.

Installation

Requires PHP 5.3+ and Composer.

composer require ikr/xml-fu:~1.1

API

Core

XmlFu\value($xml, $xpath, $default)

Searches the $xml string for the first node matching the given $xpath, and returns its string value. If the node wasn't found, the $default value is returned.

XmlFu\firstNode($xml, $xpath)

Returns a SimpleXMLElement instance for the first node matching the given $xpath in the given $xml string.

XmlFu\chunks($xml, $xpath)

Finds all the nodes in the passed $xml string matching the given $xpath, and returns an array of their asXML() serializations -- strings.

XmlFu\attrValues($xml, $elementXpath, $attrName)

Finds all the elements in the passed $xml string matching the given $elementXpath, and returns an array of their $attrName attribute values -- one string value per element.

Core without parsing

There are *Impl versions of the core functions, accepting $rootElement-s -- SimpleXMLElement instances instead of the $xml strings.

XmlFu\valueImpl($rootElement, $xpath, $default)
XmlFu\firstNodeImpl($rootElement, $xpath)
XmlFu\chunksImpl($rootElement, $xpath)
XmlFu\attrValuesImpl($rootElement, $elementXpath, $attrName)

That way you can avoid unnecessary multiple parsing runs when querying for multiple values.

Dealing with the default namespace

SimpleXMLElement::xpath() have some quirks dealing with the default XML namespace declaration: the xmlns="..." attribute. As soon as it's present, all the nodes contained by the element with xmlns declared, and the declaring element itself must be prefixed with a namespace in XPath queries. XmlFu conveniently aliases the default namespace with underscore -- _

Thus,

$xml = <<<XML
    <OTA_PingRS xmlns="http://www.opentravel.org/OTA/2003/05">
        <Success />
        <EchoData>Hey!</EchoData>
    </OTA_PingRS>    
XML;

echo XmlFu\value($xml, '//_:EchoData', null); // 'Hey!'

Extras

XmlFu\removeXmlProcessingInstruction($xml)

Removes the <?xml ... declaration from the passed $xml string. The removal is done in a safe way: no reg-exps, honest parsing.

XmlFu\rootTagName($xml)

The name of the topmost XML element in the passed $xml string.

Development status

Used in production.