After extensive search and experiment, this code worked for me:
use Drupal\taxonomy\Entity\Term;
use Drupal\views\ViewExecutable;
/**
* Implements hook_views_pre_build().
*/
function YOUR_MODULE_NAME_views_pre_build(ViewExecutable $view) {
if ($view->id() == 'YOUR_VIEW_ID' && $view->current_display == 'YOUR_DISPLAY_ID') {
// Get the exposed filter for the taxonomy terms.
$filter = $view->display_handler->getHandler('filter', 'YOUR_FILTER_ID');
if ($filter) {
// Query the database for taxonomy terms with a weight of 0.
$query = \Drupal::entityQuery('taxonomy_term');
$query->condition('weight', 0);
$term_ids = $query->execute();
if (!empty($term_ids)) {
// Load the first term found with a weight of 0.
$term = Term::load(array_shift($term_ids));
if ($term) {
// Set the default value for the exposed filter to the term's ID.
$filter->options['value'] = $term->id();
}
}
}
}
}
This code will query the database for taxonomy terms with a weight of 0 when the specified view is pre-built and set the default value for the exposed filter to the ID of the first term it finds. If no terms are found with a weight of 0, it will not change the default value.
