[DI] ContainerInterface lacks documentation regarding behavior constants

[kiler129]

\Symfony\Component\DependencyInjection\ContainerInterface contains the following constants:

    const EXCEPTION_ON_INVALID_REFERENCE = 1;
    const NULL_ON_INVALID_REFERENCE = 2;
    const IGNORE_ON_INVALID_REFERENCE = 3;
    const IGNORE_ON_UNINITIALIZED_REFERENCE = 4;

The documentation for their usage with get() is nowhere to be found. I tried looking for their usage in the Symfony code, but deciphering what they precisely do (and what's the actual intention of using them) is rather hard.

Maybe we should document that?

[nicolas-grekas]

For reference, uninitialized refs have been introduced in symfony/symfony#24033
4.1 also introduced \RUNTIME_EXCEPTION_ON_INVALID_REFERENCE = 0` in symfony/symfony#26627

Up for a doc PR @kiler129?

[geek-merlin]

This is an issue for me when i want to inject an optional service via static constructor injection in Drupal. (Not sure if this is the richt component though, maybe it should be filed against DI component.)

[carsonbot]

Thank you for this issue.
There has not been a lot of activity here for a while. Has this been resolved?

[carsonbot]

Friendly reminder that this issue exists. If I don't hear anything I'll close this.

[geek-merlin]

Yes, this is still an issue.

[carsonbot]

Thank you for this issue.
There has not been a lot of activity here for a while. Has this been resolved?