allow cache even if a closure get used for query_builder

[dominikzogg]

Q	A
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets
License	MIT
Doc PR

Using entity types within a collection, can get very slow, if a query_builder option is set.

Without this option, the doctrine type handles everything itself, and makes it calls against the manager registry, but using this, calls the getLoader method, which ends in build the choice list again for each collection element, which makes more than twice the time for a page load within my energycalculator.

https://github.com/dominikzogg/symfony/blob/2.7/src/Symfony/Bridge/Doctrine/Form/Type/DoctrineType.php#L68

https://github.com/dominikzogg/symfony/blob/2.7/src/Symfony/Bridge/Doctrine/Form/Type/DoctrineType.php#L108

https://github.com/dominikzogg/energycalculator/blob/master/src/Dominikzogg/EnergyCalculator/Form/ComestibleType.php

[dominikzogg]

@fabpot any news on this? if its to weird, i would suggest a compromise, which only caches if $queryBuilder is a QueryBuilder instance.

[Tobion]

AFAIK, the caching of query builder has been previously removed because it could return a different query each time. So if this new caching implementation compensates this, it needs to be tested.

[dominikzogg]

#13864