Allow nested attributes to be set for the given associations. Options:

• :destroy - Allow destruction of nested records.
• :fields - If provided, should be an Array. Restricts the fields allowed to be modified through the association_attributes= method to the specific fields given.
• :limit - For *_to_many associations, a limit on the number of records that will be processed, to prevent denial of service attacks.
• :remove - Allow disassociation of nested records (can remove the associated object from the parent object, but not destroy the associated object).
• :strict - Set to false to not raise an error message if a primary key is provided in a record, but it doesn‘t match an existing associated object.

If a block is provided, it is passed each nested attribute hash. If the hash should be ignored, the block should return anything except false or nil.

[Source]

    # File lib/sequel/plugins/nested_attributes.rb, line 43
43:         def nested_attributes(*associations, &block)
44:           include(self.nested_attributes_module ||= Module.new) unless nested_attributes_module
45:           opts = associations.last.is_a?(Hash) ? associations.pop : {}
46:           reflections = associations.map{|a| association_reflection(a) || raise(Error, "no association named #{a} for #{self}")}
47:           reflections.each do |r|
48:             r[:nested_attributes] = opts
49:             r[:nested_attributes][:reject_if] ||= block
50:             def_nested_attribute_method(r)
51:           end
52:         end