[3.x]: GraphQL collision when making two queries in different parameters

[eduardoalonsoalbella]

What happened?

Description

If I make a query over two parameters (featured and branches), one call takes over the other one:

Steps to reproduce

1. Create a entry query with

featured: children(hasDescendants: false) {
   title
}
branches: children(hasDescendants: true) {
   title
}

The results of both results will be the same and it should not

Expected behavior

Both results should be different

Actual behavior

Craft CMS version

3.7.61

PHP version

8.1

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

[brianjhanson]

Hey @eduardoalonsoalbella! I’ve been looking into this and just wanted to provide an update.

This is a side effect of how we eager load elements when handling a graphql request. To make things as performant as possible, when a query comes in, we traverse and parse the query and look for any and all elements that we can eager load. Eager loadable elements are thrown into an eager loading plan to be executed when the query is run.

Critically, for a handful of fields we don’t differentiate the eager loading plans based on the alias. Tracking down the original reason for that is something I need to dig into further, but in the meantime the EVENT_REGISTER_GQL_EAGERLOADABLE_FIELDS event will let you enable the aliases for children if you want, which seems to resolve the issue for me.

use craft\events\RegisterGqlEagerLoadableFields;
use craft\fields\BaseRelationField;
use craft\gql\ElementQueryConditionBuilder;

Event::on(
    ElementQueryConditionBuilder::class,
    ElementQueryConditionBuilder::EVENT_REGISTER_GQL_EAGERLOADABLE_FIELDS,
    function(RegisterGqlEagerLoadableFields $event) {
        $event->fieldList['children'] = [BaseRelationField::class, 'canBeAliased' => true];
    }
);

I need to ask around internally before I know if that’s a change we can or should implement for everyone, but hopefully, it will get you over this issue for now. It will likely have performance implications, but it’s hard to know how severe they’ll be since that will depend on your particular project.

[brandonkelly]

Craft 3.7.63 and 4.3.6 are out with #12494 merged in, allowing children fields to be aliased.