<?php
<?

Class QuizXMLReader
{
	
	private $reader;
	private $tag;
	
	// if $ignoreDepth == 1 then will parse just first level, else parse 2th level too
	/*
	 * Example:
	 * 			parseBlock('quiz_question'):
	 *
	 * 				<quiz_question>
						<question_text><![CDATA[]]></question_text>
						<question_image><![CDATA[]]></question_image>
						<question_info>
							<question_date></question_date>
							<question_rating></question_rating>
						</question_info>
					</quiz_question>

				$ignoreDepth = 1
				return
					array(
							[question_text]
							[question_image]
					)

				$ignoreDepth = 0
					return
						array(
							[question_text]
							[question_image]
							[question_info] = array (
												[question_date]
												[question_rating]
											)
						)
	 */
	private function parseBlock($name, $ignoreDepth = 1) {
		if ($this->reader->name == $name && $this->reader->nodeType == XMLReader::ELEMENT) {
			$result = array();
			while (!($this->reader->name == $name && $this->reader->nodeType == XMLReader::END_ELEMENT)) {
				//echo $this->reader->name. ' - '.$this->reader->nodeType." - ".$this->reader->depth."\n";
				switch ($this->reader->nodeType) {
					case 1:
						if ($this->reader->depth > 3 && !$ignoreDepth) {
							$result[$nodeName] = (isset($result[$nodeName]) ? $result[$nodeName] : array());
							while (!($this->reader->name == $nodeName && $this->reader->nodeType == XMLReader::END_ELEMENT)) {
								$resultSubBlock = $this->parseBlock($this->reader->name, 1);
								
								if (!empty($resultSubBlock))
									$result[$nodeName][] = $resultSubBlock;
								
								unset($resultSubBlock);
								$this->reader->read();
							}
						}
						$nodeName = $this->reader->name;
						if ($this->reader->hasAttributes) {
							$attributeCount = $this->reader->attributeCount;
							
							for ($i = 0; $i < $attributeCount; $i++) {
								$this->reader->moveToAttributeNo($i);
								$result['attr'][$this->reader->name] = $this->reader->value;
							}
							$this->reader->moveToElement();
						}
						break;
					
					case 3:
					case 4:
						$result[$nodeName] = $this->reader->value;
						$this->reader->read();
						break;
				}
				
				$this->reader->read();
			}
			return $result;
		}
	}
	
	private function quiz_categories() {
		
		if ($this->reader->name == 'quiz_categories') {
			// while not found end tag read blocks
			while (!($this->reader->name == 'quiz_categories' && $this->reader->nodeType == XMLReader::END_ELEMENT)) {
				$quiz_category = $this->parseBlock('quiz_category');
				//DO SOMETHING
				unset($quiz_category);
				$this->reader->read();
			}
			
			$this->reader->read();
		}
	}
	
	private function quiz_certificates() {
		if ($this->reader->name == 'quiz_certificates') {
			$quiz_certificates = $this->parseBlock('quiz_certificates');
			//DO SOMETHING
		}
	}
	
	public function parse($filename) {
		
		if (!$filename) return array();
		
		$this->reader = new XMLReader();
		$this->reader->open($filename);
		
		// begin read XML
		while ($this->reader->read()) {
			
			$this->quiz_categories();
			$this->quiz_certificates();
			
		} // while
	} // func
}

$xmlr = new QuizXMLReader();
$r = $xmlr->parse('export.xml');