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File: xml_domit_getelementsbypath.php

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  Classes of John Heinstein  >  DOMIT XML parser  >  xml_domit_getelementsbypath.php  >  Download  
File: xml_domit_getelementsbypath.php
Role: Class source
Content type: text/plain
Description: Allows the retreival of DOM elements using simple path-like expressions
Class: DOMIT XML parser
A Document Object Model (DOM) compliant xml parser
Author: By
Last change:
Date: 9 years ago
Size: 8,768 bytes
 

Contents

Class file image Download
<?php
/**
* @package domit-xmlparser
* @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/domit/ DOMIT! Home Page
* DOMIT! is Free Software
**/

if (!defined('DOMIT_INCLUDE_PATH')) {
   
define('DOMIT_INCLUDE_PATH', (dirname(__FILE__) . "/"));
}

/** Separator for elements path */
define('GET_ELEMENTS_BY_PATH_SEPARATOR', '/');
/** Constant for an absolute path search (starting at the document root) */
define('GET_ELEMENTS_BY_PATH_SEARCH_ABSOLUTE', 0);
/** Constant for a relative path search (starting at the level of the calling node) */
define('GET_ELEMENTS_BY_PATH_SEARCH_RELATIVE', 1);
/** Constant for a variable path search (finds all matches, regardless of place in the hierarchy) */
define('GET_ELEMENTS_BY_PATH_SEARCH_VARIABLE', 2);

/**
* getElementsByPath is a simple utility for path-based access to nodes in a DOMIT! document.
*/
class DOMIT_GetElementsByPath {
   
/** @var Object The node from which the search is called */
   
var $callingNode;
   
/** @var int The type of search to be performed, i.e., relative, absolute, or variable */
   
var $searchType;
   
/** @var Object The node that is the current parent of the search */
   
var $contextNode;
   
/** @var array An array containing a series of path segments for which to search */
   
var $arPathSegments = array();
   
/** @var Object A DOMIT_NodeList of matching nodes */
   
var $nodeList;
   
/** @var Object The index of the current node of the search */
   
var $targetIndex;
   
/** @var Object if true, the search will be aborted once the first match is found */
   
var $abortSearch = false;
   
   
/**
    * Constructor - creates an empty DOMIT_NodeList to store matching nodes
    */
   
function DOMIT_GetElementsByPath() {
        require_once(
DOMIT_INCLUDE_PATH . 'xml_domit_nodemaps.php');
       
$this->nodeList = new DOMIT_NodeList();
    }
//DOMIT_GetElementsByPath
   
    /**
    * Parses the supplied "path"-based pattern
    * @param Object The node from which the search is called
    * @param string The pattern
    * @param int The node level of the current search
    * @return Object The NodeList containing matching nodes
    */
   
function &parsePattern(&$node, $pattern, $nodeIndex = 0) {
       
$this->callingNode =& $node;
       
$pattern = trim($pattern);
       
       
$this->determineSearchType($pattern);
       
$this->setContextNode();
       
$this->splitPattern($pattern);
   
       
$this->targetIndex = $nodeIndex;
       
$totalSegments = count($this->arPathSegments);
       
        if (
$totalSegments > 0) {
            if (
$this->searchType == GET_ELEMENTS_BY_PATH_SEARCH_VARIABLE) {
               
$arContextNodes =& $this->contextNode->ownerDocument->getElementsByTagName($this->arPathSegments[0]);
               
$totalContextNodes = $arContextNodes->getLength();
               
                for (
$i = 0; $i < $totalContextNodes; $i++) {
                   
$this->selectNamedChild($arContextNodes->item($i), 1);
                }
            }
            else {
                if (
$this->searchType == GET_ELEMENTS_BY_PATH_SEARCH_ABSOLUTE) {
                    if (
$this->contextNode->nodeName == $this->arPathSegments[0]) {
                        if (
count($this->arPathSegments) == 1) {
                           
$this->nodeList->appendNode($this->contextNode);
                        }
                        else {
                           
$this->selectNamedChild($this->contextNode, 1);
                        }
                    }
                }
                else if (
$this->searchType == GET_ELEMENTS_BY_PATH_SEARCH_RELATIVE) {
                   
$this->selectNamedChild($this->contextNode, 0);
                }
            }
        }
   
        if (
$nodeIndex > 0) {
            if (
$nodeIndex <= $this->nodeList->getLength()) {
                return
$this->nodeList->item(($nodeIndex - 1));
            }
            else {
               
$null = null;
                return
$null;
            }
        }
       
        return
$this->nodeList;
    }
//parsePattern
   
    /**
    * Determines the type of search to be performed: absolute, relative, or variable
    * @param string The pattern
    */
   
function determineSearchType($pattern) {
       
$firstChar = $pattern{0};
       
        if (
$firstChar != GET_ELEMENTS_BY_PATH_SEPARATOR) {
           
//relative path
           
$this->searchType = GET_ELEMENTS_BY_PATH_SEARCH_RELATIVE;
        }
        else {
           
$secondChar = $pattern{1};
               
            if (
$secondChar != GET_ELEMENTS_BY_PATH_SEPARATOR) {
               
//absolute path
               
$this->searchType = GET_ELEMENTS_BY_PATH_SEARCH_ABSOLUTE;
            }
            else {
               
//variable path
               
$this->searchType = GET_ELEMENTS_BY_PATH_SEARCH_VARIABLE;
            }
        }
    }
//determineSearchType
   
   
    /**
    * Sets the context node, i.e., the node from which the search begins
    */
   
function setContextNode() {
        switch(
$this->searchType) {
            case
GET_ELEMENTS_BY_PATH_SEARCH_ABSOLUTE:
               
$this->contextNode =& $this->callingNode->ownerDocument->documentElement;
                break;
               
            case
GET_ELEMENTS_BY_PATH_SEARCH_RELATIVE:
                if (
$this->callingNode->uid != $this->callingNode->ownerDocument->uid) {
                   
$this->contextNode =& $this->callingNode;
                }
                else {
                   
$this->contextNode =& $this->callingNode->ownerDocument->documentElement;
                }
                break;

            case
GET_ELEMENTS_BY_PATH_SEARCH_VARIABLE:
               
$this->contextNode =& $this->callingNode->ownerDocument->documentElement;
                break;
        }
    }
//setContextNode
   
    /**
    * Splits the supplied pattern into searchable segments
    * @param string The pattern
    */
   
function splitPattern($pattern) {
        switch(
$this->searchType) {
            case
GET_ELEMENTS_BY_PATH_SEARCH_ABSOLUTE:
               
$lastIndex = 1;
                break;
               
            case
GET_ELEMENTS_BY_PATH_SEARCH_RELATIVE:
               
$lastIndex = 0;
                break;

            case
GET_ELEMENTS_BY_PATH_SEARCH_VARIABLE:
               
$lastIndex = 2;
                break;
        }
       
       
$this->arPathSegments = explode(GET_ELEMENTS_BY_PATH_SEPARATOR, substr($pattern, $lastIndex));
    }
//splitPattern
   
    /**
    * Matches the current path segment against the child nodes of the current context node
    * @param Object The context node
    * @param int The index in the arPathSegments array of the current path segment
    */
   
function selectNamedChild(&$node, $pIndex) {
        if (!
$this->abortSearch) {
            if (
$pIndex < count($this->arPathSegments)) { //not at last path segment
               
$name = $this->arPathSegments[$pIndex];
               
$numChildren = $node->childCount;
           
                for (
$i = 0; $i < $numChildren; $i++) {
                   
$currentChild =& $node->childNodes[$i];
       
                    if (
$currentChild->nodeName == $name) {
                       
$this->selectNamedChild($currentChild, ($pIndex + 1));
                    }
                }
            }
            else {
               
$this->nodeList->appendNode($node);
               
                if (
$this->targetIndex == $this->nodeList->getLength()) {
                   
$this->abortSearch = true;
                }
            }
        }
    }
//selectNamedChild
} //DOMIT_GetElementsByPath



/**
* getElementsByAttributePath is a temporary utility requested by a DOMIT! user for path-based access to attributes in a DOMIT! document.
* This class may be absent from future versions of DOMIT!
*/
class DOMIT_GetElementsByAttributePath {
   
/** @var Object A DOMIT_NodeList of matching attribute nodes */
   
var $nodeList;

   
/**
    * Constructor - creates an empty DOMIT_NodeList to store matching nodes
    */
   
function DOMIT_GetElementsByAttributePath() {
        require_once(
DOMIT_INCLUDE_PATH . 'xml_domit_nodemaps.php');
       
$this->nodeList = new DOMIT_NodeList();
    }
//DOMIT_GetElementsByAttributePath
   
    /**
    * Matches the current path segment against the child nodes of the current context node
    * @param Object The context node
    * @param string The pattern
    * @param int The index of the current path segment
    */
   
function &parsePattern(&$node, $pattern, $nodeIndex = 0) {
       
$beginSquareBrackets = strpos($pattern, '[');
       
        if (
$beginSquareBrackets != 0) {
           
$path = substr($pattern, 0, $beginSquareBrackets);
           
           
$attrPattern = substr($pattern, (strpos($pattern, '@') + 1));
           
$attrPattern = substr($attrPattern, 0, strpos($attrPattern, ')'));

           
$commaIndex = strpos($attrPattern, ',');
           
$key = trim(substr($attrPattern, 0, $commaIndex));
           
$value = trim(substr($attrPattern, ($commaIndex + 1)));
           
$value = substr($value, 1, (strlen($value) - 2));

           
$gebp = new DOMIT_GetElementsByPath();
           
$myResponse =& $gebp->parsePattern($node, $path);

           
$total = $myResponse->getLength();
           
            for (
$i = 0; $i < $total; $i++) {
               
$currNode =& $myResponse->item($i);
               
                if (
$currNode->hasAttribute($key)) {
                    if (
$currNode->getAttribute($key) == $value) {
                       
$this->nodeList->appendNode($currNode);
                    }
                }
            }
        }

        if (
$nodeIndex == 0) {
            return
$this->nodeList;
        }
        else {
            if (
$nodeIndex <= $this->nodeList->getLength()) {
                return
$this->nodeList->item(($nodeIndex - 1));
            }
            else {
               
$this->nodeList = new DOMIT_NodeList();
                return
$this->nodeList;
            }
        }
    }
//parsePattern
} //DOMIT_GetElementsByAttributePath
?>