FOSElasticaBundle _parent mapping

config.yml

    indexes:
        projects:
            client: default
            finder: ~
            types:
                github_repository:
                    mappings:
                        name:
                            type: string
                            index: not_analyzed
                        full_name:
                            type: string
                            index: not_analyzed
                        owner_login:
                            type: string
                            index: not_analyzed

                github_pull:
                    mappings:
                        user_login:
                            type: string
                            index: not_analyzed
                        assignee_login:
                            type: string
                            index: not_analyzed
                        milestone_title:
                            type: string
                            index: not_analyzed
                        updated_at:
                            type: date
                    _parent:
                        type: github_repository
                        property: repository
                        identifier: id