Class: AssociationScope::Scope::ThroughReflection

Inherits:
Scope
  • Object
show all
Defined in:
lib/association_scope/scope/through_reflection.rb

Instance Method Summary collapse

Instance Method Details

#apply ⇒ Object 



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# File 'lib/association_scope/scope/through_reflection.rb', line 6

def apply
  association = @association
  class_name = begin
    reflection_details.klass
  rescue ActiveRecord::AmbiguousSourceReflectionForThroughAssociation
    # Rails cannot resolve an omitted source when multiple source
    # reflections exist; retain the historical association-name
    # fallback for this inherently ambiguous case.
    association.singularize.camelize.constantize
  end
  source = begin
    reflection_details.source_reflection
  rescue ActiveRecord::AmbiguousSourceReflectionForThroughAssociation
    nil
  end
  validate_scope!(reflection_details)
  source ||= reflection_details.through_reflection.klass.reflections.values.find do |candidate|
    candidate.name.to_s == association.to_s && candidate.klass == class_name && candidate.through_reflection?
  end
  if source&.through_reflection?
    first_join = source.options[:through]
    second_join = reflection_details.options[:through].to_sym
  else
    first_join = inverse_reflection(class_name)&.options&.fetch(:through, nil) || inverse_reflection(class_name)&.options&.fetch(:source, nil)
    second_join = compute_second_join class_name
  end

  raise AssociationMissingError.new missing_in: class_name, association: inverse unless inverse_reflection(class_name)
  through_reflection = reflection_details.through_reflection
  through_table = through_reflection.klass.table_name
  through_key = through_reflection.belongs_to? ? through_reflection.association_primary_key : through_reflection.foreign_key
  source_key = through_reflection.belongs_to? ? through_reflection.foreign_key : through_reflection.active_record_primary_key
  owner_key = model.arel_table[source_key]
  partition_key = through_reflection.klass.arel_table[through_key]
  association_scope = reflection_details.scope
  source_scope = source&.scope
  validate_scope!(source) if source
  singular = reflection_details.macro == :has_one

  model.scope association.pluralize, -> do
    relation = Scope.target_relation(class_name, source_scope, association_scope)
      .joins(first_join => second_join)
      .where(through_table => {through_key => reselect(owner_key)})
    singular ? Scope.one_per_owner(relation, partition_key) : relation.distinct
  end
end