Exclude taxonomy term from select list on node add page

Question

I have a view that shows guest user generated articles grouped by taxonomy terms. There is just one taxonomy term which I don't want that users add articles with (only logged in users should). So how can I exclude this taxonomy term from the select list on the node add page? I suppose by some function in the theme file?

Answer 1

You need to implement hook_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) inside a custom module.

https://api.drupal.org/api/drupal/core%21lib%21Drupal%21Core%21Form%21form.api.php/function/hook_form_alter/8.2.x

Inside the form parameter you should be able to unset the specific option that you don't want to be displayed.