<?php
/**
* SAXY_Parser_Base is a base class for SAXY and SAXY Lite
* @package saxy-xmlparser
* @version 1.0
* @copyright (C) 2004 John Heinstein. All rights reserved
* @license http://www.gnu.org/copyleft/lesser.html LGPL License
* @author John Heinstein <johnkarl@nbnet.nb.ca>
* @link http://www.engageinteractive.com/saxy/ SAXY Home Page
* SAXY is Free Software
**/

/** the initial characters of a cdata section */
define('SAXY_SEARCH_CDATA', '![CDATA[');
/** the length of the initial characters of a cdata section */
define('SAXY_CDATA_LEN', 8);
/** the initial characters of a notation */
define('SAXY_SEARCH_NOTATION', '!NOTATION');
/** the initial characters of a doctype */
define('SAXY_SEARCH_DOCTYPE', '!DOCTYPE');
/** saxy parse state, just before parsing an attribute */
define('SAXY_STATE_ATTR_NONE', 0);
/** saxy parse state, parsing an attribute key */
define('SAXY_STATE_ATTR_KEY', 1);
/** saxy parse state, parsing an attribute value */
define('SAXY_STATE_ATTR_VALUE', 2);

/**
* The base SAX Parser class
*
* @package saxy-xmlparser
* @author John Heinstein <johnkarl@nbnet.nb.ca>
*/
class SAXY_Parser_Base {
	/** @var int The current state of the parser */
	var $state;
	/** @var int A temporary container for parsed characters */
	var $charContainer;
	/** @var Object A reference to the start event handler */
	var $startElementHandler;
	/** @var Object A reference to the end event handler */
	var $endElementHandler;
	/** @var Object A reference to the data event handler */
	var $characterDataHandler;
	/** @var Object A reference to the CDATA Section event handler */
	var $cDataSectionHandler = null;
	/** @var boolean True if predefined entities are to be converted into characters */
	var $convertEntities = true;
	/** @var Array Translation table for predefined entities */
	var $predefinedEntities = array('&amp;' => '&', '&lt;' => '<', '&gt;' => '>',
							'&quot;' => '"', '&apos;' => "'"); 
	/** @var Array User defined translation table for entities */
	var $definedEntities = array();
	/** @var boolean True if whitespace is to be preserved during parsing. NOT YET IMPLEMENTED! */
	var $preserveWhitespace = false;
	
		
	/**
	* Constructor for SAX parser
	*/					
	function __construct() {
		$this->charContainer = '';
	} //SAXY_Parser_Base
	
	/**
	* Sets a reference to the handler for the start element event 
	* @param mixed A reference to the start element handler 
	*/
	function xml_set_element_handler($startHandler, $endHandler) {
		$this->startElementHandler = $startHandler;
		$this->endElementHandler = $endHandler;
	} //xml_set_element_handler
	
	/**
	* Sets a reference to the handler for the data event 
	* @param mixed A reference to the data handler 
	*/
	function xml_set_character_data_handler($handler) {
		$this->characterDataHandler =& $handler;
	} //xml_set_character_data_handler
	
	/**
	* Sets a reference to the handler for the CDATA Section event 
	* @param mixed A reference to the CDATA Section handler 
	*/
	function xml_set_cdata_section_handler($handler) {
		$this->cDataSectionHandler =& $handler;
	} //xml_set_cdata_section_handler
	
	/**
	* Sets whether predefined entites should be replaced with their equivalent characters during parsing
	* @param boolean True if entity replacement is to occur 
	*/
	function convertEntities($truthVal) {
		$this->convertEntities = $truthVal;
	} //convertEntities
	
	/**
	* Appends an array of entity mappings to the existing translation table
	* 
	* Intended mainly to facilitate the conversion of non-ASCII entities into equivalent characters 
	* 
	* @param array A list of entity mappings in the format: array('&amp;' => '&');
	*/
	function appendEntityTranslationTable($table) {
		$this->definedEntities = $table;
	} //appendEntityTranslationTable
	

	/**
	* Gets the nth character from the end of the string
	* @param string The text to be queried 
	* @param int The index from the end of the string
	* @return string The found character
	*/
	function getCharFromEnd($text, $index) {
		$len = strlen($text);
		$char = $text{($len - 1 - $index)};
		
		return $char;
	} //getCharFromEnd
	
	/**
	* Parses the attributes string into an array of key / value pairs
	* @param string The attribute text
	* @return Array An array of key / value pairs
	*/
	function parseAttributes($attrText) {
		$attrText = trim($attrText);	
		$attrArray = array();
		$maybeEntity = false;			
		
		$total = strlen($attrText);
		$keyDump = '';
		$valueDump = '';
		$currentState = SAXY_STATE_ATTR_NONE;
		$quoteType = '';
		
		for ($i = 0; $i < $total; $i++) {								
			$currentChar = $attrText{$i};
			
			if ($currentState == SAXY_STATE_ATTR_NONE) {
				if (trim($currentChar != '')) {
					$currentState = SAXY_STATE_ATTR_KEY;
				}
			}
			
			switch ($currentChar) {
				case "\t":
					if ($currentState == SAXY_STATE_ATTR_VALUE) {
						$valueDump .= $currentChar;
					}
					else {
						$currentChar = '';
					}
					break;
				
				case "\x0B": //vertical tab	
				case "\n":
				case "\r":
					$currentChar = '';
					break;
					
				case '=':
					if ($currentState == SAXY_STATE_ATTR_VALUE) {
						$valueDump .= $currentChar;
					}
					else {
						$currentState = SAXY_STATE_ATTR_VALUE;
						$quoteType = '';
						$maybeEntity = false;
					}
					break;
					
				case '"':
					if ($currentState == SAXY_STATE_ATTR_VALUE) {
						if ($quoteType == '') {
							$quoteType = '"';
						}
						else {
							if ($quoteType == $currentChar) {
								if ($this->convertEntities && $maybeEntity) {
								    $valueDump = strtr($valueDump, $this->predefinedEntities);
									$valueDump = strtr($valueDump, $this->definedEntities);
								}
								
								$keyDump = trim($keyDump);
								$attrArray[$keyDump] = $valueDump;
								$keyDump = $valueDump = $quoteType = '';
								$currentState = SAXY_STATE_ATTR_NONE;
							}
							else {
								$valueDump .= $currentChar;
							}
						}
					}
					break;
					
				case "'":
					if ($currentState == SAXY_STATE_ATTR_VALUE) {
						if ($quoteType == '') {
							$quoteType = "'";
						}
						else {
							if ($quoteType == $currentChar) {
								if ($this->convertEntities && $maybeEntity) {
								    $valueDump = strtr($valueDump, $this->predefinedEntities);
									$valueDump = strtr($valueDump, $this->definedEntities);
								}
								
								$keyDump = trim($keyDump);
								$attrArray[$keyDump] = $valueDump;
								$keyDump = $valueDump = $quoteType = '';
								$currentState = SAXY_STATE_ATTR_NONE;
							}
							else {
								$valueDump .= $currentChar;
							}
						}
					}
					break;
					
				case '&':
					//might be an entity
					$maybeEntity = true;
					$valueDump .= $currentChar;
					break;
					
				default:
					if ($currentState == SAXY_STATE_ATTR_KEY) {
						$keyDump .= $currentChar;
					}
					else {
						$valueDump .= $currentChar;
					}
			}
		}

		return $attrArray;
	} //parseAttributes		
	
	/**
	* Parses character data
	* @param string The character data
	*/
	function parseBetweenTags($betweenTagText) {
		if (trim($betweenTagText) != ''){
			$this->fireCharacterDataEvent($betweenTagText);
		}
	} //parseBetweenTags	
	
	/**
	* Fires a start element event
	* @param string The start element tag name
	* @param Array The start element attributes
	*/
	function fireStartElementEvent($tagName, $attributes) {
		call_user_func($this->startElementHandler, $this, $tagName, $attributes);
	} //fireStartElementEvent		
	
	/**
	* Fires an end element event
	* @param string The end element tag name
	*/
	function fireEndElementEvent($tagName) {
		call_user_func($this->endElementHandler, $this, $tagName);
	} //fireEndElementEvent
	
	/**
	* Fires a character data event
	* @param string The character data
	*/
	function fireCharacterDataEvent($data) {
		if ($this->convertEntities && ((strpos($data, "&") != -1))) {
			$data = strtr($data, $this->predefinedEntities);
			$data = strtr($data, $this->definedEntities);
		}
		
		call_user_func($this->characterDataHandler, $this, $data);
	} //fireCharacterDataEvent	
	
	/**
	* Fires a CDATA Section event
	* @param string The CDATA Section data
	*/
	function fireCDataSectionEvent($data) {
		call_user_func($this->cDataSectionHandler, $this, $data);
	} //fireCDataSectionEvent	
} //SAXY_Parser_Base

?>
