dom_import_simplexml - PHP code example

Using the PHP Function DOM_Import_Simplexml()

PHP has a lot of functionality for working with XML documents. One of the more powerful functions is the SimpleXMLElement::importNode() function, which allows you to import a DOM node into a SimpleXMLElement object. In this article, we’ll take a look at this function and how it can be used in your code.

DOM stands for Document Object Model, which is a set of classes that represent the underlying structure of an XML document. The DOM library also provides several interfaces for accessing the underlying structure via methods such as XPath.

The dom_import_simplexml() function in SimpleXML is similar to DOMDocument::getElementsByTagName(), except that it searches for an element by its unique id value, rather than by its name. The result is an array of SimpleXMLElement objects containing the nodes in the document that match the specified id.

SimpleXML is usually easier to work with than DOM, but there are times when DOM’s comprehensiveness lets you do something that’s hard or impossible in SimpleXML. For instance, SimpleXML doesn’t allow you to discover the name of a root element, while DOM can do this with ease.

The dom_import_simplexml() method in SimpleXML helps you to work around this limitation by allowing you to convert any DOM object into a SimpleXMLElement, then use the SimpleXMLElement::importNode() method to turn the SimpleXMLElement into a DOM node. This method is an invaluable tool for any developer who works with XML in PHP. I hope that this article has been helpful to you, and if you have any questions or comments, please feel free to leave them below!

dom_import_simplexml example

/** * Tests the value being passed and decide what sort of element to create. * * @throws NotEncodableValueException */
    private function selectNodeType(\DOMNode $node, mixed $val, string $format, array $context): bool
    {
        if (\is_array($val)) {
            return $this->buildXml($node, $val, $format, $context);
        } elseif ($val instanceof \SimpleXMLElement) {
            $child = $node->ownerDocument->importNode(dom_import_simplexml($val), true);
            $node->appendChild($child);
        } elseif ($val instanceof \Traversable) {
            $this->buildXml($node, $val, $format, $context);
        } elseif ($val instanceof \DOMNode) {
            $child = $node->ownerDocument->importNode($val, true);
            $node->appendChild($child);
        } elseif (\is_object($val)) {
            if (null === $this->serializer) {
                throw new BadMethodCallException(sprintf('The serializer needs to be set to allow "%s()" to be used with object data.', __METHOD__));
            }

$child = $xml->addChild($sectionName);

                    if (isset($extends[$sectionName])) {
                        $child->addAttribute('zf:extends', $extends[$sectionName], Zend_Config_Xml::XML_NAMESPACE);
                    }

                    $this->_addBranch($data, $child, $xml);
                }
            }
        }

        $dom = dom_import_simplexml($xml)->ownerDocument;
        $dom->formatOutput = true;

        $xmlString = $dom->saveXML();

        return $xmlString;
    }

    /** * Add a branch to an XML object recursively * * @param Zend_Config $config * @param SimpleXMLElement $xml * @param SimpleXMLElement $parent * @return void */

$config[$key] = $value;
                }
            }
        }

        // Search for local 'const' nodes and replace them         if (count($xmlObject->children(self::XML_NAMESPACE)) > 0) {
            if (count($xmlObject->children()) > 0) {
                throw new Zend_Config_Exception("A node with a 'const' childnode may not have any other children");
            }

            $dom                 = dom_import_simplexml($xmlObject);
            $namespaceChildNodes = array();

            // We have to store them in an array, as replacing nodes will             // confuse the DOMNodeList later             foreach ($dom->childNodes as $node) {
                if ($node instanceof DOMElement && $node->namespaceURI === self::XML_NAMESPACE) {
                    $namespaceChildNodes[] = $node;
                }
            }

            foreach ($namespaceChildNodes as $node) {