lib/passive_record/associations/has_many_through.rb
module PassiveRecord
module Associations
class HasManyThroughAssociation < Struct.new(:parent_class, :child_class_name, :target_name_symbol, :through_class, :base_association, :habtm)
def to_relation(parent_model)
HasManyThroughRelation.new(self, parent_model)
end
end
class HasManyThroughRelation < HasManyRelation
def <<(child)
if nested_association.is_a?(HasManyAssociation)
intermediary_id =
child.send(association.base_association.target_name_symbol.to_s.singularize + "_id")
if intermediary_id
intermediary_relation.child_class.find(intermediary_id).
send(:"#{parent_model_id_field}=", parent_model.id)
else
nested_ids_field = nested_association.children_name_sym.to_s.singularize + "_ids"
intermediary_model = intermediary_relation.singular? ?
intermediary_relation.lookup_or_create :
intermediary_relation.where(parent_model_id_field => parent_model.id).first_or_create
intermediary_model.update(
nested_ids_field => intermediary_model.send(nested_ids_field) + [ child.id ]
)
end
else
intermediary_model = intermediary_relation.
where(
association.target_name_symbol.to_s.singularize + "_id" => child.id).
first_or_create
end
self
end
def create(attrs={})
child = child_class.create(attrs)
send(:<<, child)
child
end
def nested_class
module_name = association.parent_class.name.deconstantize
module_name = "Object" if module_name.empty?
(module_name.constantize).
const_get("#{association.base_association.child_class_name.singularize}")
end
def nested_association
nested_class.associations.detect { |assn|
assn.child_class_name == association.child_class_name ||
assn.child_class_name == association.child_class_name.singularize ||
(assn.parent_class_name == association.child_class_name rescue false) ||
(assn.parent_class_name == association.child_class_name.singularize rescue false) ||
assn.target_name_symbol == association.target_name_symbol.to_s.singularize.to_sym
}
end
def all
join_results = intermediate_results
if intermediate_results && !join_results.empty?
final_results = join_results.flat_map(&nested_association.target_name_symbol)
if final_results.first.is_a?(Associations::Relation)
final_results.flat_map(&:all).compact
else
Array(final_results.compact)
end
else
[]
end
end
def intermediary_relation
@intermediary_relation ||= association.base_association.to_relation(parent_model)
end
def intermediate_results
if intermediary_relation.singular?
Array(intermediary_relation.lookup)
else
intermediary_relation.all
end
end
def where(conditions={})
Core::HasManyThroughQuery.new(
child_class,
parent_model,
association.target_name_symbol,
conditions
)
end
end
end
end