DOMDocument::registerNodeClass()
(PHP 5 >= 5.2.0, PHP 7)
Register extended class used to create base node type
说明
public DOMDocument::registerNodeClass(string $baseclass,string $extendedclass): bool
This method allows you to register your own extended DOM class to be used afterward by the PHP DOM extension.
This method is not part of the DOM standard.
参数
- $baseclass
The DOM class that you want to extend. You can find a list of these classes in the chapter introduction.
- $extendedclass
Your extended class name. If
NULL
is provided, any previously registered class extending$baseclasswill be removed.
返回值
成功时返回TRUE
,或者在失败时返回FALSE
。
更新日志
版本 | 说明 |
---|---|
5.2.2 | Prior to 5.2.2, a previously registered$extendedclasshad to be unregistered before being able to register a new class extending the same$baseclass. |
范例
Example #1 Adding a new method to DOMElement to ease our code
<?php class myElement extends DOMElement { function appendElement($name) { return $this->appendChild(new myElement($name)); } } class myDocument extends DOMDocument { function setRoot($name) { return $this->appendChild(new myElement($name)); } } $doc = new myDocument(); $doc->registerNodeClass('DOMElement', 'myElement'); // From now on, adding an element to another costs only one method call ! $root = $doc->setRoot('root'); $child = $root->appendElement('child'); $child->setAttribute('foo', 'bar'); echo $doc->saveXML(); ?>
以上例程会输出:
<?xml version="1.0"?> <root><child foo="bar"/></root>
Example #2 Retrieving elements as custom class
<?php class myElement extends DOMElement { public function __toString() { return $this->nodeValue; } } $doc = new DOMDocument; $doc->loadXML("<root><element><child>text in child</child></element></root>"); $doc->registerNodeClass("DOMElement", "myElement"); $element = $doc->getElementsByTagName("child")->item(0); var_dump(get_class($element)); // And take advantage of the __toString method.. echo $element; ?>
以上例程会输出:
string(9) "myElement" text in child
Example #3 Retrieving owner document
When instantiating a custom DOMDocument theownerDocumentproperty will refer to the instantiated class, meaning there is no need(and in fact not possible)to use DOMDocument::registerNodeClass() with DOMDocument
<?php class myDOMDocument extends DOMDocument { } class myOtherDOMDocument extends DOMDocument { } // Create myDOMDocument with some XML $doc = new myDOMDocument; $doc->loadXML("<root><element><child>text in child</child></element></root>"); $child = $doc->getElementsByTagName("child")->item(0); // The current owner of the node is myDOMDocument var_dump(get_class($child->ownerDocument)); // Import a node from myDOMDocument $newdoc = new myOtherDOMDocument; $child = $newdoc->importNode($child); // The new owner of the node has changed to myOtherDOMDocument var_dump(get_class($child->ownerDocument)); ?>
以上例程会输出:
string(13) "myDOMDocument" string(18) "myOtherDOMDocument"
Creating innerHTML and outerHTML <?php class DOMHTMLElement extends DOMElement { function __construct() { parent::__construct();} public function innerHTML() { $doc = new DOMDocument(); foreach ($this->childNodes as $child){ $doc->appendChild($doc->importNode($child, true)); } $content = $doc->saveHTML(); return $content; } public function outerHTML() { $doc = new DOMDocument(); $doc->appendChild($doc->importNode($this, true)); $content = $doc->saveHTML(); return $content; } } $dom = DOMDocument::loadHTMLFile($file); $dom->registerNodeClass('DOMElement','DOMHTMLElement'); if($dom) { $xpath = new DOMXpath($dom); $regions = $xpath->query("//*[contains(@class, 'editable')]"); $content = ''; foreach($regions as $region){ $content .= $region->outerHTML(); } return $content; }else{ throw new Exception('Cannot parse HTML. Please verify the syntax is correct.'); } ?>
Note than save and saveXML are not affected by __toString().