How Can I Correctly Add A Footer Row To The CSV Programmatically?

Introduction

When working with CSV exports in Drupal 10, especially when using Views, it's common to need to add a footer row to the exported file. This footer row can contain various information, such as the total number of records, the last updated date, or any other relevant data. In this article, we'll explore how to add a footer row to a CSV programmatically using the hook_views_data_export_row_alter() hook in Drupal 10.

Understanding the hook_views_data_export_row_alter() Hook

The hook_views_data_export_row_alter() hook is a powerful tool in Drupal 10 that allows developers to modify the data exported by Views. This hook is called after the data has been retrieved from the database but before it's exported to the file. By using this hook, you can add, remove, or modify data in the exported file.

Adding a Footer Row to the CSV

To add a footer row to the CSV, you'll need to use the hook_views_data_export_row_alter() hook. This hook takes three arguments: $view, $data, and $row. The $view argument is an instance of the Drupal\views\ViewExecutable class, the $data argument is an array containing the data to be exported, and the $row argument is an array containing the current row of data.

Here's an example of how you can use the hook_views_data_export_row_alter() hook to add a footer row to the CSV:

use Drupal\views\ViewExecutable;
use Drupal\views\Row;
/**

Implements hook_views_data_export_row_alter().
*/
function mymodule_views_data_export_row_alter(ViewExecutable view, &data, Row row) {
// Get the total number of records.
total_records = $view->display_handler->get_option('total_records');

// Add a footer row to the data array.
$footer_row = [
'total_records' => $total_records,
'last_updated' => \Drupal::time()->getRequestTime(),
];
// Add the footer row to the data array.
$data[] = $footer_row;
}

In this example, we're getting the total number of records from the view's display handler and adding a footer row to the data array. The footer row contains two fields: total_records and last_updated. The last_updated field is set to the current request time using the Drupal::time()->getRequestTime() method.

Displaying the Footer Row in the CSV

To display the footer row in the CSV, you'll need to modify the CSV export settings in the View. To do this, follow these steps:

1. Go to the View's settings page.
2. Click on the "Export" tab.
3. Click on the "CSV" export format.
4. In the "CSV settings" section, click on the "Advanced" tab.
5. In the "Footer row" section, select the "Add a footer row" option.
6. In the "Footer row fields" section, select the fields you want to display in the footer row.

Example Use Case

Let's say you have a View that exports a list of products, and you want to add a footer row to the CSV that shows the total number of products and the last updated date. To do this, you can use the hook_views_data_export_row_alter() hook to add a footer row to the data array, and then modify the CSV export settings in the View to display the footer row.

Here's an example of how you can use the hook_views_data_export_row_alter() hook to add a footer row to the CSV:

use Drupal\views\ViewExecutable;
use Drupal\views\Row;
/**

Implements hook_views_data_export_row_alter().
*/
function mymodule_views_data_export_row_alter(ViewExecutable view, &data, Row row) {
// Get the total number of records.
total_records = $view->display_handler->get_option('total_records');

// Add a footer row to the data array.
$footer_row = [
'total_records' => $total_records,
'last_updated' => \Drupal::time()->getRequestTime(),
];
// Add the footer row to the data array.
$data[] = $footer_row;
}

In this example, we're getting the total number of records from the view's display handler and adding a footer row to the data array. The footer row contains two fields: total_records and last_updated. The last_updated field is set to the current request time using the Drupal::time()->getRequestTime() method.

Conclusion

Q: What is the hook_views_data_export_row_alter() hook?

A: The hook_views_data_export_row_alter() hook is a powerful tool in Drupal 10 that allows developers to modify the data exported by Views. This hook is called after the data has been retrieved from the database but before it's exported to the file.

Q: How do I use the hook_views_data_export_row_alter() hook to add a footer row to a CSV?

A: To use the hook_views_data_export_row_alter() hook to add a footer row to a CSV, you'll need to implement the hook in your module's mymodule.module file. Here's an example of how you can use the hook to add a footer row to a CSV:

use Drupal\views\ViewExecutable;
use Drupal\views\Row;
/**

Implements hook_views_data_export_row_alter().
*/
function mymodule_views_data_export_row_alter(ViewExecutable view, &data, Row row) {
// Get the total number of records.
total_records = $view->display_handler->get_option('total_records');

// Add a footer row to the data array.
$footer_row = [
'total_records' => $total_records,
'last_updated' => \Drupal::time()->getRequestTime(),
];
// Add the footer row to the data array.
$data[] = $footer_row;
}

Q: How do I display the footer row in the CSV?

A: To display the footer row in the CSV, you'll need to modify the CSV export settings in the View. To do this, follow these steps:

1. Go to the View's settings page.
2. Click on the "Export" tab.
3. Click on the "CSV" export format.
4. In the "CSV settings" section, click on the "Advanced" tab.
5. In the "Footer row" section, select the "Add a footer row" option.
6. In the "Footer row fields" section, select the fields you want to display in the footer row.

Q: Can I add multiple footer rows to a CSV?

A: Yes, you can add multiple footer rows to a CSV by modifying the hook_views_data_export_row_alter() hook to add multiple rows to the data array. Here's an example of how you can add multiple footer rows to a CSV:

use Drupal\views\ViewExecutable;
use Drupal\views\Row;
/**

Implements hook_views_data_export_row_alter().
*/
function mymodule_views_data_export_row_alter(ViewExecutable view, &data, Row row) {
// Get the total number of records.
total_records = $view->display_handler->get_option('total_records');

// Add multiple footer rows to the data array.
$footer_rows = [
[
'total_records' => $total_records,
'last_updated' => \Drupal::time()->getRequestTime(),
],
[
'total_records' => $total_records,
'last_updated' => \Drupal::time()->getRequestTime() - 86400, // 1 day ago
],
];
// Add the footer rows to the data array.
$data[] = $footer_rows;
}

Q: Can I customize the appearance of the footer row?

A: Yes, you can customize the appearance of the footer row by modifying the CSV export settings in the View. To do this, follow these steps:

1. Go to the View's settings page.
2. Click on the "Export" tab.
3. Click on the "CSV" export format.
4. In the "CSV settings" section, click on the "Advanced" tab.
5. In the "Footer row" section, select the "Customize appearance" option.
6. In the "Footer row fields" section, select the fields you want to display in the footer row and customize their appearance as needed.

Q: Can I use the hook_views_data_export_row_alter() hook to add a footer row to other types of exports?

A: Yes, you can use the hook_views_data_export_row_alter() hook to add a footer row to other types of exports, such as JSON or XML exports. However, you'll need to modify the hook to accommodate the specific export format and data structure.

Conclusion

Adding a footer row to a CSV programmatically in Drupal 10 is a powerful tool that can help you customize the exported data to meet your needs. By using the hook_views_data_export_row_alter() hook, you can add, remove, or modify data in the exported file. In this article, we've explored some common questions and answers related to using the hook_views_data_export_row_alter() hook to add a footer row to a CSV.