Exporting Laravel Model to Excel but with modification of created_at column to only date not datetime - excel

Question

i tried to modify a collection before returning it to be exported with maatwebsite Excel. The column i tried to modify is the created_date column (the default created_date of laravel) so that when exported to excel, i only get the date not datetime.
i tried:
namespace App\Exports;
use App\Invoice;
use Maatwebsite\Excel\Concerns\FromCollection;
class InvoicesExport implements FromCollection
{
public function collection()
{
$temp = Invoice::all();
$len = count($temp);
for($i=0;$i<$len;$i+=1){
$temp[$i]->created_at = $temp[$i]->created_at->format('m/d/Y')
}
return $temp;
}
}
in the controller:
public function export()
{
return Excel::download(new InvoicesExport, 'invoices.xlsx');
}
but, when exported, the result in the excel file is, for example: '07/26/2016T00:00:00.000000Z'
i noticed that the time become zero, and when i tried:
$temp[$i]->created_at = "some random string"
the laravel in webpage return error said that "some random string" cannot be parsed to datetime by Carbon Class constructor.
how can i make the exporting does not construct datetime with the string i give in the 'created_at' column, but just return the plain string instead? if let's say, i can't modify the database so i can't create extra column and extra column for this simple thing is too much, i think.

Answer 1

If you are using Maatwebsite\Excel 2.1 try column formatting by the setColumnFormat($array) method.
If Maatwebsite\Excel 3.1, try with the WithMapping interface.

Answer 2

created_at is marked as 'datetime' in the $cast property of your model by default so when you set it it's automatically cast as date (with Carbon::parse('the value you gave'))
If you want to export your collection with some values formatted you should not mutate the objects of the original objects but create new dedicated objects/arrays that will not interfere with model behavior nor corrupt your existing objects.