query_hint_resolver.md

Resolving of ORM query hints

The Query Hint Resolver service has been introduced to make the building of a configuration based queries (like grids, API, etc) easier and more flexible.

To map a hint to a custom tree walker you can use DI container configuration, for example:

    oro_security.query_hint.filter_by_current_user:
        public: false
        abstract: true
        tags:
            -
                name: oro_entity.query_hint
                hint: oro_security.filter_by_current_user
                alias: HINT_FILTER_BY_CURRENT_USER
                tree_walker: Oro\Bundle\SecurityBundle\ORM\Walker\CurrentUserWalker
                walker_hint_provider: oro_security.walker_hint_provider.current_user

Please pay attention on walker_hint_provider attribute. It is optional and can be used to provide a service to be used to set additional query hints required to work the walker specified in the attribute tree_walker. This service must implement QueryWalkerHintProviderInterface and must be registered in DI container, for example:

    oro_security.walker_hint_provider.current_user:
        public: false
        class: Oro\Bundle\SecurityBundle\ORM\Walker\CurrentUserWalkerHintProvider
        arguments:
             - @security.context

To map a hint to a custom output walker use the attribute output_walker instead of tree_walker in DI container configuration, for example:

    oro_translation.query_hint.translatable:
        public: false
        abstract: true
        tags:
            -
                name: oro_entity.query_hint
                hint: oro_translation.translatable
                alias: HINT_TRANSLATABLE
                output_walker: %oro_translation.translation_walker.class%

The following example shows how hints can be used in YAML configuration files:

datagrids:
    my-email-origins-grid:
        source:
            type: orm
            query:
                select:
                    - origin
                from:
                    - { table: %oro_email.email_origin.entity.class%, alias: origin }
            hints:
                - HINT_FILTER_BY_CURRENT_USER