module Hanami
module Model
# Mapped proxy for ROM relations.
#
# It eliminates the need to use #as for repository queries
#
# @since 1.0.0
# @api private
class MappedRelation < SimpleDelegator
# Mapper name.
#
# With ROM mapping there is a link between the entity class and a generic
# reference for it. Example: BookRepository references Book
# as :entity.
#
# @since 1.0.0
# @api private
MAPPER_NAME = :entity
# @since 1.0.0
# @api private
def self.mapper_name
MAPPER_NAME
end
# @since 1.0.0
# @api private
def initialize(relation)
@relation = relation
super(relation.as(self.class.mapper_name))
end
# Access low level relation's attribute
#
# @param attribute [Symbol] the attribute name
#
# @return [ROM::SQL::Attribute] the attribute
#
# @raise [Hanami::Model::UnknownAttributeError] if the attribute cannot be found
#
# @since 1.2.0
#
# @example
# class UserRepository < Hanami::Repository
# def by_matching_name(name)
# users
# .where(users[:name].ilike(name))
# .map_to(User)
# .to_a
# end
# end
def [](attribute)
@relation[attribute]
rescue KeyError => e
raise UnknownAttributeError.new(e.message)
end
end
end
end