Undefined Entity Issue

I'm experiencing the same issue:

Patch #1 by @Tristanwellz didn't fix the error in my case.

After all, there are chances that $entity can't be retrieved in this final check either:

    if (!isset($entity) && \Drupal::request()->attributes->has('entity')) {
      $entity = \Drupal::request()->attributes->get('entity');
    }

Which is what happens in my case, when entities are rendered in a preprocess query for entities indexed by Search API.

In short, I think it's necessary to add a final check before we return the $entity:

return isset($entity) ? $entity : null;

Attached patch with this solution fixes the problem for me.

Hi. I also have the same issue and I tested patch from #3. It applied successfully and solved the issue. Logs are clear. Changing status to RTBC.

Thank you for the contribution! I would like some tests to cover the case where this error shows up; can a test be added? Or if not, if someone can tell me how to recreate the error, I can look at writing the test myself.

Another example of creating the error where the entity variable can't be retrieved is in layout builder. For example, I have a layout for node type Article.

1. Enable layout builder
2. Manage form display for Article (/admin/structure/types/manage/article/display)
3. Select Use Layout Builder under Layout options
4. Create new block view with "Format: Entity Pager" with circular enabled in Settings
5. Add some fields, filters, sort criteria (optional)
6. Add block view to Article layout

In layout builder, there is no entity variable as we're not viewing an entity/node. Entity pager does not know where we are in the pagination. So we get the following errors:

Notice: Undefined variable: entity in Drupal\entity_pager\EntityPager->getEntity() (line 119 of modules\contrib\entity_pager\src\EntityPager.php).
Notice: Undefined variable: entity in Drupal\entity_pager\EntityPager->getEntity() (line 123 of modules\contrib\entity_pager\src\EntityPager.php).

I've tested patch in #3 against 1.x-dev today and it is working. No more undefined variable errors.

@Wongjn Can we set this to RTBC? I've outlined an example of how to recreate the error. The patch is a fairly simple one.

Still needs tests please! If no one does write any, I can have a look soon.