Currently, the validator will traverse objects that implement\Traversable if

• the object was reached via aValid constraint withtraverse set totrue
• the parameter$traverse was set totrue when callingValidator::validate()

This has two negative consequences:

• it's impossible to specify only once that a specific class should never/always be traversed
• it's impossible to specify whether an object should be traversed whenValidator::validate() is not called manually, but through another system (e.g. the Form component - see[Form][Bug] Embedded form validation bubbling #8557)

A solution would be to add configuration parameters for specifying the traversal policy on a class level, for example:

// not traversed by defaultclass Fooimplements \IteratorAggregate{// ...}// traversed/** @Assert\Traverse */class Barimplements \IteratorAggregate{}// traversed recursively/** @Assert\Traverse(deep=true) */class Bazimplements \IteratorAggregate{}