Currently, there is no way to alter the exported rows within one operation, just the way to alter a single row by this call:
\Drupal::moduleHandler()->alter('views_data_export_row', $output, $row, $this->view);
But, in some cases, it's helpful to receive all the rows as arguments and alter them by some conditions. For example, case of my project:
I need to append some external data from API for each exported row (so kind of an extra column). But I need to perform 1*N (number of rows) API requests within the existing implementation and that is not so good in terms of performance/API limitations.
Add another alter hook that will be called right after the loop over the view rows is finished (similar to what other modules do), here - views_data_export/src/Plugin/views/style/DataExport.php:244.
No
A new alter hook.
Needs review
1.0
Code
Added a patch with a new alter hook. Please, review.
@quadrexdev Thanks,
The patch works as expected.