Generate CSV File and Force Browser to Download It in CodeIgniter

So, as the title implies, this is not general PHP approach, it is about how to do that in CodeIgniter.

Here is the solution found from the Internet: Excel CSV helper for CodeIgniter

But this snippet won't work for UTF-8 encoded characters. So I copied the code in the comment (posted by [e-mail]) discussing that issue:

if ($download != "")
{
	/*
	header('Content-Encoding: UTF-8');
	header('Content-Type: text/csv; charset=UTF-8');
	//header('Content-Type: application/csv; charset=UTF-8');
	header('Content-Disposition: attachment; filename="' . $download . '"');
	echo "\xEF\xBB\xBF"; // UTF-8 BOM
	*/

	header('Content-Description: File Transfer');
	//header('Content-Type: application/octet-stream');
	header("Content-Type: application/vnd.ms-excel; charset=UTF-16LE");
	header('Content-Disposition: attachment; filename='.$download);
	header('Content-Transfer-Encoding: binary');
	header('Expires: 0');
	header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
	header('Pragma: public');
	//echo "\xEF\xBB\xBF"; // UTF-8 BOM
	echo "\xFF\xFE"; // UTF-16 LE
}

My final code came to be:

if ( ! function_exists('array_to_csv'))
{
	function array_to_csv($array, $download = "")
	{
		$CI =& get_instance();
		
		if ($download != "")
		{	
			header('Content-Encoding: UTF-8');
			header('Content-Type: text/csv; charset=UTF-8');
			header('Content-Disposition: attachment; filename="' . $download . '"');
			echo "\xEF\xBB\xBF"; // UTF-8 BOM
		}		

		ob_start();
		$f = @fopen('php://output', 'w');
		if (FALSE === $f)
		{
			$this->CI->app88log->log_message('csv', 'error', "Can't open php://output");
			show_error($this->CI->lang->line('admin_export_excel_error_message'));
		}
		
		$n = 0;		
		foreach ($array as $line)
		{
			$n++;
			try {
				$res = fputcsv($f, $line);
				if (FALSE === $res) 
				{
					$this->CI->app88log->log_message('csv', 'error', 'Can not write line' . $n );
					show_error($this->CI->lang->line('admin_export_excel_error_message'));
				}
			}
			catch (Exception $e) {
				$this->CI->app88log->log_message('csv', 'error', $e->getMessage());
				show_error($this->CI->lang->line('admin_export_excel_error_message'));
			}
		}
		
		fclose($f);
		$str = ob_get_contents();
		ob_end_clean();

		if ($download == "")
		{
			return $str;	
		}
		else
		{
			echo $str;
		}		
	}
}

And it was saved under /application/helper/.

Then load it in controllers' constructor, and call it in method:

		$fileName = 'product-' . gmdate('Y-m-d') . '.csv';
		array_to_csv($csvData, $fileName);
		exit;

Pass the two-dimension array of data to the function and let it take care of all the job left.