Helper para exportar dados para Excel

excel.php

<?php 

class ExcelHelper extends AppHelper 
{
	var $filename = 'arquive.csv';
	
	var $rows = array();
	
	var $header = "<?xml version=\"1.0\" encoding=\"UTF-8\"?\>
<Workbook xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\"
 xmlns:x=\"urn:schemas-microsoft-com:office:excel\"
 xmlns:ss=\"urn:schemas-microsoft-com:office:spreadsheet\"
 xmlns:html=\"http://www.w3.org/TR/REC-html40\">";
 
	var $footer = "</Workbook>";
	
	var $worksheet_title = "Table";
	
	function getHeaders () {
		header("Content-Type: application/vnd.ms-excel; charset=UTF-8");
		header("Content-Disposition: inline; filename=\"" . $this->filename . ".xls\"");
	}
	
	function addRow ($data = array()) {
		
		foreach($data as $key => $value) {
			$data[$key] = "<Cell><Data ss:Type=\"String\">" . $value . "</Data></Cell>\n"; 
		}
		
		$this->rows[] = $data;
	}
	
	function setTitle ($title) {
		$title = preg_replace ("/[\\\|:|\/|\?|\*|\[|\]]/", "", $title);
		$title = substr ($title, 0, 31);
		$this->worksheet_title = $title;
	}
	
	function render ($file = null) {
		$this->filename = ($file) ? $file : $this->filename;
		$this->getHeaders();
		
		$out = array();
		foreach($this->rows as $row) {
			$out[] = "<Row>\n" . implode('', $row) . "</Row>\n";
		}
		
		$data = implode("\n", $out);
		
		echo stripslashes ($this->header);
		echo "\n<Worksheet ss:Name=\"" . $this->worksheet_title . "\">\n<Table>\n";
		echo "<Column ss:Index=\"1\" ss:AutoFitWidth=\"0\" ss:Width=\"110\"/>\n";
		echo $data;
		echo "</Table>\n</Worksheet>\n";
		echo $this->footer;
		
		echo $data;
	}
}