phpexcel removecolumn taking too much time - phpexcel

Question

I will write my requirements and how I write code to achieve it.
I have to generate and save excel file on server with specific styles and formulae. Which user will later download. User will have to select which columns he want when generating excel.
logic I wrote
I placed an excel file with similar styling already on server but with empty cells which I will fill later. That way I can avoid code of styling all those required cells.
Then I am filling all the columns with data from database. Now I read list of columns that needs to be deleted in a posted array and deleting in reverse order to make sure I delete right columns. This works but It takes too much time to delete each column. it is taking atleast 4 to 5 mins to delete single column if column number increases , deleting time is increasing exponentially.
Code
$objReader = PHPExcel_IOFactory::createReader('Excel5');
$objPHPExcel = $objReader->load($inputFileName);
$objPHPExcel->getProperties()->setCreator(user_data('name'))
->setLastModifiedBy(user_data('name'))
->setTitle("Grid file")
->setSubject("Grid file")
->setDescription("Grid file")
->setKeywords("Grid file")
->setCategory("Grids");
$col = 0;
$worksheet = $objPHPExcel->getActiveSheet();
for ($i = 19; $i < count($grid_items) + 19; $i++) {
$col = 0;
foreach ($grid_items[$i - 19] as $columnname => $value) {
$coval = PHPExcel_Cell::stringFromColumnIndex($col) . ($i);
$worksheet->setCellValue($coval, $value);
$col++;
}
}
$worksheet->removeColumnByIndex(11);
$worksheet->removeColumnByIndex(12);
$worksheet->removeColumnByIndex(13);
$worksheet->removeColumnByIndex(14);
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
$finalFilename = 'Master_Grid_excel_' . $this->job_id . '-' . date('Y-m-d-H-i-s') . '.xls';
$objWriter->save(SITE_ROOT . 'uploads/rfp/' . $finalFilename);
return ;

Answer 1

Well removeColumn() is computationally intensive anyway; but you are calling it 4 times when you only need to call it once. The removeColumn() and removeColumnByIndex() methods accept an optional second argument specifying the number of columns to remove, defaulting to 1; but if you want to remove a number of consecutive columns (such as 11, 12, 13 and 14) then you can do:
$worksheet->removeColumnByIndex(11, 4);
and that 1 call will be 4 times faster than 4 individual calls.
Note that the same additional argument applies to removing rows as well as columns; and to inserting columns and rows as well.
However: if you modified the logic of your
foreach ($grid_items[$i - 19] as $columnname => $value) {
loop so that it didn't write those columns in the first place, and you removed any unnecessary columns to eliminate the header line entries before that loop; then you wouldn't be executing the removeColumn() against a fully populated spreadsheet.

Answer 2

when you run $worksheet->removeColumnByIndex(11) and next column is 12 change to =>11
so you can try to use ..php function array_reverse() big=>small
$d= array_reverse(sort($chk));
foreach ($d as $v){
$worksheet->removeColumnByIndex($v);
}