Programmatically removing value from multi-valued field of a content type

Question

I have a custom content type with a field (id is field_link_to_persona) that is multi-valued text. In my UI I have checkboxes that correspond to values in that field and if I uncheck the box and save I want to remove the value from the field.

I load the node like this:

$nodes = \Drupal::entityTypeManager()
            ->getStorage('node')
            ->loadByProperties(['type' => 'document', 'nid' => $docID ]);

            $node = reset($nodes);

I can add new values like this:

$node->field_link_to_persona[] = $newValue;

But how do I remove one? I tried

$node->field_link_to_persona->removeItem($id);

But I keep getting exceptions about the index not existing.

Any help would be appreciated. I'm somewhat new to drupal so no detail is too trivial :)

Answer 1

I recently ran into this same issue. Here is how I was able to make this work. In my case, I was working with a user but it can be easily updated for a node as well.

$user = User::load(\Drupal::currentUser()->id());
$id_to_remove = '81' // Make sure to update this to be the actual id you want to remove through something like $term->id().

// Get the field
$my_field = $user->get('field_my_field');
$my_field_values = $my_field->getValue();

// Get the index to remove
$index_to_remove = array_search($id_to_remove,array_column($my_field_values,'target_id'));

// Actually remove the item
$my_field->removeItem($index_to_remove);

// save the user
$user->save();