symfony/symfony — pull request #8861 by Inori (2013-08-26 18:28:44+00:00)
Title: [Bridge][Doctrine][Validator] allow UniqueEntity constraint to be set on external class

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

Use case for this feature would be if you want to validate data on a DTO before actually mapping it to the Entity itself.