QuiteSimpleXMLElement

The QuiteSimpleXMLElement class is a small wrapper built around the SimpleXMLElement class that adds some convenience methods and makes it easier to work with namespaces. The main reason for developing the class was to let objects returned by the xpath() method inherit namespaces from the original object. The package was formerly known as CustomXMLElement.

QuiteSimpleXMLElement supports PHP 5.6 and 7.x. If you need PHP 5.3 support, use the 0.4.* version range as PHP 5.3 support was removed in version 0.5.

The library is actively maintained and pull requests are welcome.

Why this library was developed

Taking an example document,

$xml = '<root xmlns:dc="http://purl.org/dc/elements/1.1/">
    <dc:a>
      <dc:b >
        1.9
      </dc:a>
    </dc:b>
  </root>';

Using SimpleXMLElement I found myself having to register namespaces over and over again:

$root = new SimpleXMLElement($xml);
$root->registerXPathNamespace('d', 'http://purl.org/dc/elements/1.1/');
$a = $root->xpath('d:a');
$a[0]->registerXPathNamespace('d', 'http://purl.org/dc/elements/1.1/');
$b = $a[0]->xpath('d:b');

When using QuiteSimpleXMLElement, it should only be necessary to register the namespaces once and for all.

$node = new QuiteSimpleXMLElement($xml);
$node->registerXPathNamespace('d', 'http://purl.org/dc/elements/1.1/');
$a = $node->xpath('d:a');
$b = $a->xpath('d:b');

The namespaces can also be defined using the alternative constructor QuiteSimpleXMLElement::make:

$node = QuiteSimpleXMLElement::make($xml, ['d' => 'http://purl.org/dc/elements/1.1/']);
$a = $node->xpath('d:a');
$b = $a->xpath('d:b');

A note on the design: I would have preferred to extend the original SimpleXMLElement class, but the constructor is static, which is why I wrote a wrapper instead.

Helper methods

The library defines some new methods to support less typing and cleaner code.

attr($name)

Returns the value of an attribute as a string. Namespace prefixes are supported.

echo $node->attr('id');

text($xpath)

Returns the text content of the node

echo $node->text('d:a/d:b');

first($xpath)

Returns the first node that matches the given path, or null if none.

$node = $node->first('d:a/d:b');

all($xpath)

Returns all nodes that matches the given path, or an empty array if none.

$node = $node->all('d:a/d:b');

has($xpath)

Returns true if the node exists, false if not

if ($node->has('d:a/d:b') {
	…
}

setValue($value)

Sets the value of a node

$node->setValue('Hello world');

replace($newNode)

Replaces the current node with a new one. Example:

$book = new QuiteSimpleXMLElement('
<book>
	<chapter>
		<title>Chapter one</title>
	</chapter>
	<chapter>
		<title>Chapter two</title>
	</chapter>
</book>
');

$introduction = new QuiteSimpleXMLElement('
	<introduction>
		<title>Introduction</title>
	</introduction>
');

$firstChapter = $book->first('chapter');
$firstChapter->replace($introduction);

gives

<?xml version="1.0"?>
<book>
    <introduction>
        <title>Introduction</title>
    </introduction>
    <chapter>
        <title>Chapter two</title>
    </chapter>
</book>

Works with namespaces as well, but any namespaces used in the replacement node must be specified in that document as well. See QuiteSimpleXMLElementTest.php for an example.

danmichaelo/quitesimplexmlelement