Overview

s9e\SweetDOM is a library that extends PHP's DOM extension to make DOM manipulation easier, with a particular emphasis on XSLT 1.0 templates. It adds syntactic sugar for the most common DOM operations, improves compatibility across PHP versions, and implements polyfills for some of the newer methods.

Installation

composer require s9e/sweetdom

API

s9e\SweetDOM\Document

The s9e\SweetDOM\Document class extends DOMDocument and provides quick access to DOMXPath's evaluate and query methods. The firstOf method evaluates the XPath query and returns the first node of the list, or null if the list is empty.

mixed       evaluate(string $expression, ?DOMNode $contextNode = null, bool $registerNodeNS = true)
?DOMNode    firstOf(string $expression, ?DOMNode $contextNode = null, bool $registerNodeNS = true)
DOMNodeList query(string $expression, ?DOMNode $contextNode = null, bool $registerNodeNS = true)

The s9e\SweetDOM\Document class has a $nodeCreator property that provides a set of methods to create elements with an emphasis on XSL elements commonly used in templates. See s9e\SweetDOM\NodeCreator for the full content.

Comment createComment(string $data)
Element createElement(string $nodeName, string $textContent = '')
Element createElementNS(?string $namespace, string $nodeName, string $textContent = '')
Element createXslApplyTemplates(string $select = null, string $mode = null)
Element createXslAttribute(string $name, string $textContent = '', string $namespace = null)
Element createXslChoose()
Element createXslComment(string $textContent = '')
Element createXslCopyOf(string $select)
Element createXslElement(string $name, string $namespace = null, string $useAttributeSets = null)
Element createXslIf(string $test, string $textContent = '')
Element createXslOtherwise(string $textContent = '')
Element createXslText(string $textContent = '', string $disableOutputEscaping = null)
Element createXslValueOf(string $select, string $disableOutputEscaping = null)
Element createXslVariable(string $name, string $select = null)
Element createXslWhen(string $test, string $textContent = '')

s9e\SweetDOM\Element

The s9e\SweetDOM\Element class extends DOMElement and provides a set of magic methods to simultaneously create a node and insert it relative to the element. For each method from the s9e\SweetDOM\NodeCreator class, exist five corresponding methods on the s9e\SweetDOM\Element.

For instance, the createXslText method from s9e\SweetDOM\NodeCreator is declined into the afterXslText, appendXslText, beforeXslText, prependXslText, and replaceWithXslText methods in s9e\SweetDOM\Element. Each method creates a node, performs the DOM action, then returns the node. The following example illustrates where each xsl:text element is inserted relative to the span element from which they are created, then replaces the br element.

$xsl = '<xsl:template xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <p><span><br/></span></p>
</xsl:template>';

$dom                     = new s9e\SweetDOM\Document;
$dom->formatOutput       = true;
$dom->preserveWhiteSpace = false;
$dom->loadXML($xsl);

$span    = $dom->firstOf('//span');
$methods = ['afterXslText', 'appendXslText', 'beforeXslText', 'prependXslText'];
foreach ($methods as $methodName)
{
	$span->$methodName($methodName);
}
$dom->firstOf('//br')->replaceWithXslText('replaceWithXslText');
echo $dom->saveXML($dom->documentElement);

<xsl:template xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <p>
    <xsl:text>beforeXslText</xsl:text>
    <span>
      <xsl:text>prependXslText</xsl:text>
      <xsl:text>replaceWithXslText</xsl:text>
      <xsl:text>appendXslText</xsl:text>
    </span>
    <xsl:text>afterXslText</xsl:text>
  </p>
</xsl:template>

XPath methods are also accessible at the element level and use the element itself as context node:

$dom = new s9e\SweetDOM\Document;
$dom->loadXML('<x id="1"><x id="2"/></x>');

var_dump($dom->firstOf('//x')->getAttribute('id'));
var_dump($dom->firstOf('//x')->firstOf('x')->getAttribute('id'));

string(1) "1"
string(1) "2"

Elements can be easily created and added relative to the context node via the following API:

Element afterElement(string $nodeName, string $textContent = '')
Element appendElement(string $nodeName, string $textContent = '')
Element beforeElement(string $nodeName, string $textContent = '')
Element prependElement(string $nodeName, string $textContent = '')

$dom                     = new s9e\SweetDOM\Document;
$dom->formatOutput       = true;
$dom->preserveWhiteSpace = false;
$dom->loadXML('<p><span><br/></span></p>');

$span    = $dom->firstOf('//span');
$methods = ['afterElement', 'appendElement', 'beforeElement', 'prependElement'];
foreach ($methods as $methodName)
{
	$span->$methodName('i', $methodName);
}
echo $dom->saveXML($dom->documentElement);

<p>
  <i>beforeElement</i>
  <span>
    <i>prependElement</i>
    <br/>
    <i>appendElement</i>
  </span>
  <i>afterElement</i>
</p>

Document fragments can be used to batch operations, or insert XML in a DOM.

$dom = new s9e\SweetDOM\Document;
$dom->loadXML('<x/>');

$x = $dom->firstOf('//x');
$x->appendDocumentFragment(
	// The callback will be executed before the fragment is appended
	fn($fragment) => $fragment->appendXML('<y/><z/>')
);

echo $dom->saveXML($x);

<x><y/><z/></x>

Other extended nodes

The following DOM nodes are automatically extended and augmented with XPath methods as well as whichever magic methods are supported by the node type, usually via the DOMChildNode and DOMParentNode interfaces.

• s9e\SweetDOM\Attr extends DOMAttr
• s9e\SweetDOM\CdataSection extends DOMCdataSection
• s9e\SweetDOM\Comment extends DOMComment
• s9e\SweetDOM\DocumentFragment extends DOMDocumentFragment
• s9e\SweetDOM\Element extends DOMElement
• s9e\SweetDOM\Text extends DOMText

Backward and forward compatibility with older and future versions of PHP

In order to improve compatibility with older versions of PHP as well as future versions of PHP, this library uses a different set of classes to implement node types depending on the PHP version. The base classes are those listed above, in the s9e\SweetDOM namespace, and only those classes should be used when checking for class types.

Backward compatibility with older versions of PHP

Polyfills for the following methods are provided for PHP < 8.3:

• Node::isEqualNode
• ParentNode::insertAdjacentElement
• ParentNode::insertAdjacentText
• ParentNode::replaceChildren

On PHP older than 8.1.23, and on PHP versions from 8.2.0 to 8.2.9, the following methods are emulated:

• ChildNode::after
• ChildNode::before
• ChildNode::replaceWith
• ParentNode::append
• ParentNode::prepend

Forward compatibility with future versions of PHP

The following methods have been modified to match PHP 8.3's behaviour with regards to disconnected nodes (nodes with no parent) and align with the DOM specification.

• ChildNode::after
• ChildNode::before
• ChildNode::replaceWith