module ActiveRecord::AutosaveAssociation::ClassMethods

Private Instance Methods

add_autosave_association_callbacks(reflection) click to toggle source

Adds validation and save callbacks for the association as specified by the reflection.

For performance reasons, we don't check whether to validate at runtime. However the validation and callback methods are lazy and those methods get created when they are invoked for the very first time. However, this can change, for instance, when using nested attributes, which is called after the association has been defined. Since we don't want the callbacks to get defined multiple times, there are guards that check if the save or validation methods have already been defined before actually defining them.

# File lib/active_record/autosave_association.rb, line 182
def add_autosave_association_callbacks(reflection)
  save_method = :"autosave_associated_records_for_#{reflection.name}"
  validation_method = :"validate_associated_records_for_#{reflection.name}"
  collection = reflection.collection?

  unless method_defined?(save_method)
    if collection
      before_save :before_save_collection_association

      define_non_cyclic_method(save_method, reflection) { save_collection_association(reflection) }
      # Doesn't use after_save as that would save associations added in after_create/after_update twice
      after_create save_method
      after_update save_method
    else
      if reflection.macro == :has_one
        define_method(save_method) { save_has_one_association(reflection) }
        # Configures two callbacks instead of a single after_save so that
        # the model may rely on their execution order relative to its
        # own callbacks.
        #
        # For example, given that after_creates run before after_saves, if
        # we configured instead an after_save there would be no way to fire
        # a custom after_create callback after the child association gets
        # created.
        after_create save_method
        after_update save_method
      else
        define_non_cyclic_method(save_method, reflection) { save_belongs_to_association(reflection) }
        before_save save_method
      end
    end
  end

  if reflection.validate? && !method_defined?(validation_method)
    method = (collection ? :validate_collection_association : :validate_single_association)
    define_non_cyclic_method(validation_method, reflection) { send(method, reflection) }
    validate validation_method
  end
end
define_non_cyclic_method(name, reflection, &block) click to toggle source
# File lib/active_record/autosave_association.rb, line 154
def define_non_cyclic_method(name, reflection, &block)
  define_method(name) do |*args|
    result = true; @_already_called ||= {}
    # Loop prevention for validation of associations
    unless @_already_called[[name, reflection.name]]
      begin
        @_already_called[[name, reflection.name]]=true
        result = instance_eval(&block)
      ensure
        @_already_called[[name, reflection.name]]=false
      end
    end

    result
  end
end