[4.x] Eager loaded elements are null

[martinherweg]

Hey,

not sure if this is a bug or an issue on our side so a discussion rather then an issue.

We have quite a complicated page with some filtering, relations etc. where we have a problem with eager loading of an entries field.

Even if I simplify the query the problem is the same.

{% set newsQuery = craft.entries.section('news').with(['heroImage', 'topics', 'category']).limit(4).all() %}
{% for news in newsQuery %}
  {{ d(news.topics.one()) }}
{% endfor %}

The result of the dump is null for all elements, the topics are Entries and are surely set on these elements and the category for example works fine when eager loaded.
If I remove topics from the .with() I get results as wished.

Any hint on what might be the problem here and what I could look at?

Thanks.

EDIT:
Additional Info would be that it works in a different environment just fine.

[brianjhanson]

Edit because I was wrong.

Since Craft 4, eager loaded elements are returned as an craft\elements\ElementCollection which doesn't care if you use [0] or .one().

The (mostly) original answer below still applies to Craft 3 though.

You'll need to use the array syntax when accessing eager loaded elements.

{% set newsQuery = craft.entries.section('news').with(['heroImage', 'topics', 'category']).limit(4).all() %}
{% for news in newsQuery %}
  {{ d(news.topics[0]) }}
{% endfor %}

[martinherweg]

Hey @brianjhanson,

that is not correct, eager loaded elements are always a collection, your way only the newsQuery itself would also be collection.
Array syntax even throws an error Key "0" in object with ArrayAccess of class "craft\elements\ElementCollection" does not exist.

[brianjhanson]

Whoops you're right, I'll update my answer. Either way, you should still be able to access news.topics with either [0] or .one(). Can you open an issue for this so we can check it out? Any additional detail you can provide would be helpful as I'm not able to replicate with a simple project.