How can I change the label on the "Add media" button in media field widget?

Question

I would like to change the label on the button named "Add media" on the media field widget. For instance to write "Add image" or "Add document". How can I change it?

Answer 1

During the form construction process, there are a bunch of times that Drupal allows your own modules to hook in and alter things like this.

Here's one, which you would implement in a custom module, that hooks in when the media library widget is being prepared and alters it everywhere it's used:

function MYMODULE_field_widget_media_library_widget_form_alter(&$element, \Drupal\Core\Form\FormStateInterface $form_state, $context) {
  $element["open_button"]["#value"] = t('Add image');
}

Here's another one that hooks in during the construction of any node form, which might be more appropriate if I only want to make this change for a particular field or entity type:

function MYMODULE_form_node_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) {
  if (isset($form["field_my_media"])) {
    $form["field_my_media"]["widget"]["open_button"]["#value"] = t('Add image');
  }
}