In order to add a node to any group in Drupal 8, I use the following code.
$group->addContent($node, 'group_node:article');
Now, for removing content from a group, I have tried $group->removeContent($node, 'group_node:article');
and $group->removeContent($node);
without success. All I obtained is the following error message.
Error: Call to undefined method Drupal\group\Entity\Group::removeContent() in Drupal\my_valetop_extras\Plugin\WebformHandler\CustomWebformHandler->submitForm()
Finally, I have managed to remove content from a group using this code.
$type = 'group_node:' . $node->getType();
$current_node = $group->getContent($type, ['entity_id' => $node_id]);
$content = array_values($current_node)[0];
$content->delete();
But believe I can remove a single node from a group with a simple line of code.
How can I achieve it?