PHP SimpleXML Undefined Member Error

I can't figure out why this is an error. Everything makes sense to me. $logFile is a SimpleXMLElement and theirfore should be able to use the getName() method.

Error:

Fatal error: Call to a member function getName() on a non-object in C:\xampp\htdocs\objLogParser.php on line 29

I've marked the error in my code.

<?php
class objLogParser
{
    private $fileName;
    private $logFile;

    //Constructor
    public function __construct($varFileName)
    {
        $this->fileName = $varFileName;
        //Load as string
        $xmlstr = file_get_contents($varFileName);
        $logFile = new SimpleXMLElement($xmlstr);

        //Load as file
        $logFile = new SimpleXMLElement($varFileName,null,true);
    }

    public function printNodes()
    {

        $this->printHelper($this->logFile,0);
    }


    public function printHelper($currentNode, $offset)
    {

        echo $this->offset($offset);
        echo $currentNode->getName();  ////////////////////LINE 29 ERROR
        if($currentNode->attributes()->count() > 0)
            echo "({$currentNode->attributes()})";
        echo " {$currentNode}"; 

        foreach ($currentNode->children() as $child) {
            echo "开发者_StackOverflow<br>";
            printHelper($child, ($offset+1));
        }
    }

    function offset($offset)
    {
        for ($i = 0; $i < $offset; $i++)
            echo "_ ";
    }



}
?>

It should be $this->logFile->getName();. Essentially, replace $logFile with logFile.

$this->logFile is never being set. $logFile is set in __construct(), but is never actually used. $this->logFile and $logFile aren't the same variable. $logFile is limited to the scope of __construct(); you can't access it outside that method. $this->logFile can be accessed by any method in the class. Try changing $logFile in __construct() to $this->logFile.