UPSXML error with null result in xmldocument class

[lankeeyankee]

I am trying to get this module working since it can be used to pull Surepost rates. But I am getting an error from the xmldocument class file. I looked up the error message and it indicates it's because the getName() function is returning a null value. The error message in the debug log is:

PHP Fatal error:  Call to a member function getName() on a non-object in /xxx/includes/classes/xmldocument.php on line 68

My PHP knowledge is sooooo rusty, I haven't been able to figure out a fix after trying several different things and reading online about this error. Can anyone please help with figuring this out? Here's the class file, the problem is in the function getValueByPath and the line is

if ($pathArray[0] == $this->root->getName()) { 

<?php
/*
    $Id: xmldocument.php,v 1.5 2003/06/27 01:03:03 torinwalker Exp $
    Written by Torin Walker
    [email protected]

    Original copyright (c) 2003 Torin Walker
    Copyright(c) 2003 by Torin Walker, All rights reserved.

    Released under the GNU General Public License
    This program is free software; you can redistribute it and/or modify it 
    under the terms of the GNU General Public License as published by the Free 
    Software Foundation; either version 2 of the License, or (at your option) 
    any later version. This program is distributed in the hope that it will be 
    useful, but WITHOUT ANY WARRANTY; without even the implied warranty of 
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General 
    Public License for more details. You should have received a copy of the 
    GNU General Public License along with this program; If not, you may obtain 
    one by writing to and requesting one from:
    The Free Software Foundation, Inc.,
    59 Temple Place, Suite 330,
    Boston, MA 02111-1307 USA
*/

define("ELEMENT", 0);
define("TEXTELEMENT", 1);

//*****************
class XMLDocument {
    var $root;
    var $children;

    function XMLDocument() {
    }

    function createElement($name) {
        $node = new Node();
        $node->setName($name);
        $node->setType(ELEMENT);
        return $node;
    }

    function createTextElement($text) {
        $node = new Node();
        $node->setType(TEXTELEMENT);
        $node->setValue($text);
        return $node;
    }

    function getRoot() {
        return $this->root;
    }

    function setRoot($node) {
        $this->root = $node;
    }

    function toString() {
        if ($this->root) {
            return $this->root->toString();
        } else {
            return "DOCUMENT ROOT NOT SET";
        }
    }

    function getValueByPath($path) {
        $pathArray = split("/", $path);
        if ($pathArray[0] == $this->root->getName()) {
            //print_r("Looking for " . $pathArray[0] . "<br>");
            array_shift($pathArray);
            $newPath = implode("/", $pathArray);
            return $this->root->getValueByPath($newPath);
        }
    }
}

//**********
class Node {
    var $name;
    var $type;
    var $text;
    var $parent;
    var $children;
    var $attributes;

    function Node() {
        $this->children = array();
        $this->attributes = array();
    }

    function getName() {
        return $this->name;
    }

    function setName($name) {
        $this->name = $name;
    }

    function setParent(&$node) {
        $this->parent =& $node;
    }

    function &getParent() {
        return $this->parent;
    }

    function &getChildren() {
        return $this->children;
    }

    function getType() {
        return $this->type;
    }

    function setType($type) {
        $this->type = $type;
    }

    function getElementByName($name) {
        for ($i = 0; $i < count($this->children); $i++) {
            if ($this->children[$i]->getType() == ELEMENT) {
                if ($this->children[$i]->getName() == $name) {
                    return $this->children[$i];
                }
            }
        }
        return null;
    }

    function getElementsByName($name) {
        $elements = array();
        for ($i = 0; $i < count($this->children); $i++) {
            if ($this->children[$i]->getType() == ELEMENT) {
                if ($this->children[$i]->getName() == $name) {
                    $elements[] = $this->children[$i];
                }
            }
        }
        return $elements;
    }

    function getValueByPath($path) {
        $pathArray = split('/', $path);
        $node = $this;
        for ($i = 0; $i < count($pathArray); $i++) {
            //print_r("Looking for " . $pathArray[$i] ."<br>");
            if ($node->getChildren()) {
                for ($j = 0; $j < count($node->getChildren()); $j++) {
                    if ($node->children[$j]->getType() == ELEMENT) {
                        if ($node->children[$j]->getName() == $pathArray[$i]) {
                            //print_r("Found " . $pathArray[$i] ."<br>");
                            $node = $node->children[$j];
                        }
                    }
                }
            }
        }
        return $node->getValue();
    } 

    function getText() {
        return $this->text();
    }

    function setValue($text) {
        $this->text = $text;
    }

    function getValue() {
        $value = NULL;
        if ($this->getType() == ELEMENT) {
            for ($i = 0; $i < count($this->children); $i++) {
                $value .= $this->children[$i]->getValue();
            }
        } elseif ($this->getType() == TEXTELEMENT) {
            $value .= $this->text;
        }
        return $value;
    }

    function setAttribute($name, $value) {
        $attributes[$name] = $value;
    }

    function getAttribute($name) {
        return $attributes[$name];
    }

    function addNode(&$node) {
        $this->children[] =& $node;
        $node->parent =& $this;
    }

    function parentToString($node) {
        while($node->parent) {
            //print_r("Node " . $node->name . " has parent<br>");
            $node = $node->parent;
        }
        //print_r("Node contents from root: " . $node->toString() . "<br>");
    }

    function toString() {
        $string = NULL;    
        //print_r("toString child count " . $this->name . " contains " . count($this->children) . "<br>");    
        if ($this->type == ELEMENT) {
            $string .= '{' . $this->name . '}';
            for ($i = 0; $i < count($this->children); $i++) {
                $string .= $this->children[$i]->toString();
            }
            $string .= '{/' . $this->name . '}';
        } else {
            $string .= $this->getValue();
        }
        return $string;
    }
}

//**************
class XMLParser {
    var $xp;
    var $document;
    var $current;
    var $error;

    function XMLParser() {
        $this->document = new XMLDocument();
        $this->error = array();
    }

    function setDocument($document) {
        $this->document = $document;
    }

    function getDocument() {
        return $this->document;
    }

    function destruct(){
        xml_parser_free($this->xp);
    }

    // return 1 for an error, 0 for no error
    function hasErrors() {
        if (sizeof($this->error) > 0) {
            return 1;
        } else {
            return 0;
        }
    }

    // return array of error messages
    function getError() {
        return $this->error;
    }

    // process xml start tag
    function startElement($xp, $name, $attrs) {
        //print_r("Found Start Tag: " . $name . "<br>");
        $node =& $this->document->createElement($name);
        if ($this->document->getRoot()) {
            $this->current->addNode($node);
        } else {
            $this->document->root =& $node;
        }
        $this->current =& $node;
    }

    // process xml end tag
    function endElement($xp, $name){
        //print_r("Found End Tag: " . $name . "<br>");
        if ($this->current->getParent()) {
            $this->current =& $this->current->getParent();
        }
    }

    // process data between xml tags
    function dataHandler($xp, $text) {
        //print_r("Adding Data: \"" . $text . "\"<br>");
        $node =& $this->document->createTextElement($text);
        $this->current->addNode($node);
    }

    // parse xml document from string
    function parse($xmlString) {
        if(!($this->xp = @xml_parser_create())) {
            $this->error['description'] = 'Could not create xml parser';
        }
        if(!$this->hasErrors()) {
            if(!@xml_set_object($this->xp, $this)) {
                $this->error['description'] = 'Could not set xml parser for object';
            }
        }
        if(!$this->hasErrors()) {
            if(!@xml_set_element_handler($this->xp, 'startElement', 'endElement')) {
                $this->error['description'] = 'Could not set xml element handler';
            }
        }
        if(!$this->hasErrors()) {
            if(!@xml_set_character_data_handler($this->xp, 'dataHandler')) {
                $this->error['description'] = 'Could not set xml character handler';
            }
        } 
        xml_parser_set_option($this->xp, XML_OPTION_CASE_FOLDING, false);
        if (!$this->hasErrors()) {
            if(!@xml_parse($this->xp, $xmlString)) {
                $this->error['description'] = xml_error_string(xml_get_error_code($this->xp));
                $this->error['line'] = xml_get_current_line_number($this->xp);
            }
        }
    }
}
?>