reading large file in chunks with phpExcel - php

Question

I'm using phpExcel to read a rather large XML file. I'm trying to do this in chunks, as is indicated in the examples. But no matter what I try, the "$objPHPExcel = $objReader->load($inputFileName)" always fails and results in an error saying that memory is exhausted.
I have seen http://phpexcel.codeplex.com/discussions/242712?ProjectName=phpexcel and How to read large worksheets from large Excel files (27MB+) with PHPExcel? but every code I tried failed at the same load method.
This is a part of the code I'm currently using:
set_include_path(get_include_path() . PATH_SEPARATOR . '../../../Classes/');
/** PHPExcel_IOFactory */
include 'PHPExcel/IOFactory.php';
$inputFileType = 'Excel5';
// $inputFileType = 'Excel2007';
// $inputFileType = 'Excel2003XML';
// $inputFileType = 'OOCalc';
// $inputFileType = 'Gnumeric';
$inputFileName = 'testfile.xls';
/** Define a Read Filter class implementing PHPExcel_Reader_IReadFilter */
class chunkReadFilter implements PHPExcel_Reader_IReadFilter
{
private $_startRow = 0;
private $_endRow = 0;
/** We expect a list of the rows that we want to read to be passed into the constructor */
public function __construct($startRow, $chunkSize) {
$this->_startRow = $startRow;
$this->_endRow = $startRow + $chunkSize;
}
public function readCell($column, $row, $worksheetName = '') {
// Only read the heading row, and the rows that were configured in the constructor
if (($row == 1) || ($row >= $this->_startRow && $row < $this->_endRow)) {
return true;
}
return false;
}
}
$objReader = PHPExcel_IOFactory::createReader($inputFileType);
$objReader->setReadDataOnly(true);
echo '<hr />';
/** Define how many rows we want for each "chunk" **/
$chunkSize = 5;
/** Loop to read our worksheet in "chunk size" blocks **/
for ($startRow = 2; $startRow <= 240; $startRow += $chunkSize) {
echo 'Loading WorkSheet using configurable filter for headings row 1 and for rows ',$startRow,' to ',($startRow+$chunkSize-1),'<br />';
/** Create a new Instance of our Read Filter, passing in the limits on which rows we want to read **/
$chunkFilter = new chunkReadFilter($startRow,$chunkSize);
/** Tell the Reader that we want to use the new Read Filter that we've just Instantiated **/
$objReader->setReadFilter($chunkFilter);
/** Load only the rows that match our filter from $inputFileName to a PHPExcel Object **/
echo "before load <br />";
$objPHPExcel = $objReader->load($inputFileName);
echo "after load";
// Do some processing here
$sheetData = $objPHPExcel->getActiveSheet()->toArray(null,true,true,true);
var_dump($sheetData);
echo '<br /><br />';
}
So I wonder if anyone has an idea why none of the solutions in the other topics work?
Thanks,
Grtz