Add edit mode option to expand only paragraph types with paragraph field

I added the new edit mode "Closed, expand nested" to the widget settings and a test to check, if only the top level container is opened, when using this new mode.

+++ b/src/Plugin/Field/FieldWidget/ParagraphsWidget.php
@@ -384,6 +385,17 @@ class ParagraphsWidget extends WidgetBase {
 
+    if ($default_edit_mode == 'closed_expand_nested' && $form_state->getTriggeringElement() === NULL) {
+      $field_definitions = $paragraphs_entity->getFieldDefinitions();
+
+      foreach ($field_definitions as $field_definition) {
+        if ($field_definition->getType() == 'entity_reference_revisions' && $field_definition->getSetting('target_type') == 'paragraph') {
+          $item_mode = 'edit';
+          break;
+        }
+      }
+    }

So this relies on overwriting the default if this is no submission by relying on the trigger element. Interesting approach.

Wondering if it would be easier to follow if you'd instead embed it into the logic above, something like this:

elseif (closed) {
closed
}
elseif (closed_expand_nested) {
default to closed then the code you have.

Other than that, this looks great, even has test coverage for nested containers to ensure that if you do want to have nested expanded too, you can do that with the widget settings there.

It is easier and I wanted to do it like you described, but first getting the field definitions in that elseif, didn't want to work exactly how it should've, so I went with the solution I uploaded before, But after rechecking everything now, it works fine, so I updated the code.

For next time: When updating a patch, you should provide an interdiff, so that it is easier to review the changes you did. See https://www.drupal.org/documentation/git/interdiff. I usually just do that by working on a branch, and committing each version, then the interdiff is just git diff HEAD~1.

Trying to set a better title, this has nothing to do with the autocollapse feature, only the regular edit mode.

And the current label for the option is also not confusing, I suggested that and I'm not sure what else to use. We don't expand nested paragraphs, we expand paragraphs that *have* nested paragraphs :)

Miro?