method

configure_dependency_for_has_many

Ruby on Rails latest stable (v2.3.4) - 0 notes - Class: ActiveRecord::Associations::ClassMethods

configure_dependency_for_has_many(reflection, extra_conditions = nil) private

Creates before_destroy callback methods that nullify, delete or destroy has_many associated objects, according to the defined :dependent rule.

See HasManyAssociation#delete_records. Dependent associations delete children, otherwise foreign key is set to NULL.

The extra_conditions parameter, which is not used within the main Active Record codebase, is meant to allow plugins to define extra finder conditions.

Show source

# File activerecord/lib/active_record/associations.rb, line 1408
        def configure_dependency_for_has_many(reflection, extra_conditions = nil)
          if reflection.options.include?(:dependent)
            # Add polymorphic type if the :as option is present
            dependent_conditions = []
            dependent_conditions << "#{reflection.primary_key_name} = \#{record.quoted_id}"
            dependent_conditions << "#{reflection.options[:as]}_type = '#{base_class.name}'" if reflection.options[:as]
            dependent_conditions << sanitize_sql(reflection.options[:conditions], reflection.quoted_table_name) if reflection.options[:conditions]
            dependent_conditions << extra_conditions if extra_conditions
            dependent_conditions = dependent_conditions.collect {|where| "(#{where})" }.join(" AND ")
            dependent_conditions = dependent_conditions.gsub('@', '\@')
            case reflection.options[:dependent]
              when :destroy
                method_name = "has_many_dependent_destroy_for_#{reflection.name}".to_sym
                define_method(method_name) do
                  send(reflection.name).each { |o| o.destroy }
                end
                before_destroy method_name
              when :delete_all
                module_eval %Q{
                  before_destroy do |record|                  # before_destroy do |record|
                    delete_all_has_many_dependencies(record,  #   delete_all_has_many_dependencies(record,
                      "#{reflection.name}",                   #     "posts",
                      #{reflection.class_name},               #     Post,
                      %@#{dependent_conditions}@)             #     %@...@) # this is a string literal like %(...)
                  end                                         # end
                }
              when :nullify
                module_eval %Q{
                  before_destroy do |record|                  # before_destroy do |record|
                    nullify_has_many_dependencies(record,     #   nullify_has_many_dependencies(record,
                      "#{reflection.name}",                   #     "posts",
                      #{reflection.class_name},               #     Post,
                      "#{reflection.primary_key_name}",       #     "user_id",
                      %@#{dependent_conditions}@)             #     %@...@) # this is a string literal like %(...)
                  end                                         # end
                }
              else
                raise ArgumentError, "The :dependent option expects either :destroy, :delete_all, or :nullify (#{reflection.options[:dependent].inspect})"
            end
          end
        end

configure_dependency_for_has_many

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