[5.x]: Fix Typed property craft\base\FieldLayoutComponent::$elementType must not be accessed before initialization error with Kint and element queries

[engram-design]

What happened?

Refer to verbb/kint#8 but since Craft 5, the plugin cannot dump ElementQuery objects anymore. This is due to an error: Typed property craft\base\FieldLayoutComponent::$elementType must not be accessed before initialization.

To reproduce this, add an Entries field to an Entry, then use Kint to output the ElementQuery (not an element collection or single element): {{ d(craft.entries.id(123).one().entriesField) }}

Disregarding the Kint factor here, I feel like this might be a Craft issue.

Taking a deep-dive into things, this seems to be due to the craft\fieldlayoutelements\CustomField (our Entries field) doesn't have an elementType associated with it yet. It's also during this investigation that I've found when settings elements on a FieldLayoutTab that it's own elementType isn't set.

I'm not 110% sure, but shouldn't the elementType for the FieldLayoutTab and resulting CustomField objects be inherited from the FieldLayout::type property? The element type that the field layout is for?

public function setElements(array $elements): void
{
    $fieldsService = Craft::$app->getFields();
    $pluginsService = Craft::$app->getPlugins();
    $this->_elements = [];

+    // Set the element type based on the field layout's element type
+    $this->elementType = $this->layout->type;
+
    foreach ($elements as $layoutElement) {
        if (is_array($layoutElement)) {
            try {
+               // Ensure that layout elements know which element type this is for
+               $layoutElement['elementType'] = $this->elementType;
                $layoutElement = $fieldsService->createLayoutElement($layoutElement);

Which seems to fix my issue. I didn't do a PR, purely because I'm not really sure if this is right, expected behaviour or otherwise.

Craft CMS version

5.1.7

PHP version

8.2.0

Operating system and version

MacOS 14.1

Database type and version

MySQL 8

Image driver and version

No response

Installed plugins and versions

• Kint 4

[brandonkelly]

This is definitely a Kint bug. Replacing d() with dump() works fine, and shows the elementType property is set as expected for the relational query:

To be extra sure, I installed Kint and set a breakpoint in the d() handler, and elementType is definitely set at the time the query is passed to the function:

The field layout/tab/element’s elementType property has nothing to do with the element query; that is identifying the element type the field layout was created for. The element query’s elementType property is the element type the relational field’s element query is meant to fetch (e.g. craft\elements\Asset if it’s an Assets field).

[engram-design]

So the elementType not being set is actually on the custom field's layoutElement inside the element query, not on the element query itself - which you've shown is set correctly. It's hard to show in a single screenshot without it being massive, but you can check in the tree:

That's me just calling {% dd craft.entries.id(123).one().entries %} in a template.

It's the eagerLoadSourceElement, the entries field (my Entries custom field) and the field's layoutElement

I'm keenly aware that this is probably a "my problem" sort of issue, as dump() and event the similar s() (in Kint) function works correctly. It's clearly something to do with how Kint treats objects.

[brandonkelly]

Ah ok, sorry, got confused. I just set that property to null by default, which fixes that error. However now the page is timing out, so guessing there’s an infinite recursion bug or something. I’ll leave that to you :)

[engram-design]

Thanks for that, yeah probably my issue to figure out now. It's likely all to do with the kint-twig package just being stupid, but that's my problem now 😄

[brandonkelly]

Craft 5.1.8 is out with that fix.